Pub Date : 2026-10-28DOI: 10.1021/accountsmr.6c00250
Kent J. Griffith
{"title":"Simultaneous Chemical and Isotopic Monitoring of Heterogeneous Nuclear Materials Separations with NMR Spectroscopy","authors":"Kent J. Griffith","doi":"10.1021/accountsmr.6c00250","DOIUrl":"https://doi.org/10.1021/accountsmr.6c00250","url":null,"abstract":"","PeriodicalId":72040,"journal":{"name":"Accounts of materials research","volume":"5 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2026-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149272058","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-10-28DOI: 10.1021/accountsmr.6c00189
Jacinta C. Conrad,Ryan Poling-Skutvik,Mohammadjavad Haji Rezaei,Shivraj B. Kotkar,Jeremy C. Palmer
Polymer solutions are essential materials both for their uses in industries ranging from energy storage to consumer products to additive manufacturing and as model physical systems that can mimic biological tissues and hydrogels with well-controlled structures, dynamics, and properties. Nanoparticles are commonly added to these solutions to impart functionality, deliver theranostics, or manipulate mechanical properties, all of which require a fundamental understanding of nanoparticle transport through the surrounding polymer mesh. Over recent decades, nanoparticle dynamics have been analyzed using the framework of microrheology to measure the local viscoelasticity of complex fluids. In contrast to homogeneous, Newtonian fluids in which particle dynamics are described through the Stokes–Einstein-Sutherland (SES) relationship, the structural heterogeneity and viscoelasticity of polymer solutions lead to significant deviations with nanoparticles transporting up to 1,000× faster than expected from the bulk solution viscosity. These deviations dramatically alter how nanoparticles disperse and distribute through complex environments and introduce significant discrepancies between microrheological measurements and bulk mechanical properties. The vast combinatorial library of polymer chemistries, architectures, and solution formulations necessitates predictive understanding of nanoparticle transport and how it relates to the underlying physicochemical interactions. In this Account, we describe theoretical advances and summarize experimental and simulation findings that build a comprehensive understanding of nanoparticle transport in polymer solutions. The key insight is that nanoparticle transport can be better understood by considering the local dynamics and structure of the polymer solution rather than the bulk viscoelasticity. Specifically, we show that nanoparticles violate the SES relationship because they are comparable in size to structural heterogeneities and instead exhibit a size-dependent diffusivity. Using theoretical predictions derived from polymer scaling theory, the faster dynamics are related to the ratio between nanoparticle size and the polymer correlation length ξ because the nanoparticles couple to segmental fluctuations of the polymer mesh. Despite the success of this coupling theory in describing the long-time diffusivity of nanoparticles, it does not capture the dynamics on short time scales, on which nanoparticles move subdiffusively. On these time scales, the nanoparticles not only couple to segmental fluctuations but also to the center-of-mass dynamics of the polymer coils. To expand these findings across the formulation library, we detail some impacts of nanoparticle surface interactions and polymer conformation and chemistry on this modified coupling theory. The stiffness and charge of the surrounding polymer and the softness of the particle all affect how nanoparticle dynamics couple to those of the polymers. Looking forward
{"title":"Nanoparticle Transport in Polymer Solutions","authors":"Jacinta C. Conrad,Ryan Poling-Skutvik,Mohammadjavad Haji Rezaei,Shivraj B. Kotkar,Jeremy C. Palmer","doi":"10.1021/accountsmr.6c00189","DOIUrl":"https://doi.org/10.1021/accountsmr.6c00189","url":null,"abstract":"Polymer solutions are essential materials both for their uses in industries ranging from energy storage to consumer products to additive manufacturing and as model physical systems that can mimic biological tissues and hydrogels with well-controlled structures, dynamics, and properties. Nanoparticles are commonly added to these solutions to impart functionality, deliver theranostics, or manipulate mechanical properties, all of which require a fundamental understanding of nanoparticle transport through the surrounding polymer mesh. Over recent decades, nanoparticle dynamics have been analyzed using the framework of microrheology to measure the local viscoelasticity of complex fluids. In contrast to homogeneous, Newtonian fluids in which particle dynamics are described through the Stokes–Einstein-Sutherland (SES) relationship, the structural heterogeneity and viscoelasticity of polymer solutions lead to significant deviations with nanoparticles transporting up to 1,000× faster than expected from the bulk solution viscosity. These deviations dramatically alter how nanoparticles disperse and distribute through complex environments and introduce significant discrepancies between microrheological measurements and bulk mechanical properties. The vast combinatorial library of polymer chemistries, architectures, and solution formulations necessitates predictive understanding of nanoparticle transport and how it relates to the underlying physicochemical interactions.\u0000In this Account, we describe theoretical advances and summarize experimental and simulation findings that build a comprehensive understanding of nanoparticle transport in polymer solutions. The key insight is that nanoparticle transport can be better understood by considering the local dynamics and structure of the polymer solution rather than the bulk viscoelasticity. Specifically, we show that nanoparticles violate the SES relationship because they are comparable in size to structural heterogeneities and instead exhibit a size-dependent diffusivity. Using theoretical predictions derived from polymer scaling theory, the faster dynamics are related to the ratio between nanoparticle size and the polymer correlation length ξ because the nanoparticles couple to segmental fluctuations of the polymer mesh. Despite the success of this coupling theory in describing the long-time diffusivity of nanoparticles, it does not capture the dynamics on short time scales, on which nanoparticles move subdiffusively. On these time scales, the nanoparticles not only couple to segmental fluctuations but also to the center-of-mass dynamics of the polymer coils. To expand these findings across the formulation library, we detail some impacts of nanoparticle surface interactions and polymer conformation and chemistry on this modified coupling theory. The stiffness and charge of the surrounding polymer and the softness of the particle all affect how nanoparticle dynamics couple to those of the polymers. Looking forward","PeriodicalId":72040,"journal":{"name":"Accounts of materials research","volume":"254 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2026-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149272056","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-10-26DOI: 10.1021/accountsmr.6c00177
Shengyang Zhou,Zhixiang Dai,Jingyu Cao,Chao Xu
Conductive metal–organic frameworks (c-MOFs) represent a distinct class of porous conductive materials. Compared with conventional MOFs, c-MOFs integrate intrinsically high electrical conductivity with a high surface area and an ordered porous structure, enabling efficient electron and ion transport. Engineering c-MOFs into continuous and flexible films offers a promising strategy for translating their properties into practical devices. Key strategies for film engineering include solution processing, interfacial growth, and chemical vapor deposition, which allow precise control over the film morphology, thickness, and alignment of conductive channels. Thin-film fabrication preserves structural integrity and pore connectivity, enhances interfacial contact, and facilitates device integration, thereby promoting coupled ionic and electronic transport. These properties render c-MOF films suitable for multimodal energy transformation. In energy storage, their mechanical compliance, flexibility, and high porosity enable conformal integration with deformable and wearable devices while maintaining rapid charge transport and long-term cycling stability. In energy harvesting and conversion, their ordered porous networks, tunable electronic structures, and freestanding mechanically flexible architectures enable efficient adaptation to diverse energy inputs, facilitating energy conversion involving electrical, mechanical, chemical, thermal, and optical processes while maintaining the structural integrity under dynamic deformation. This versatility supports the development of integrated systems capable of simultaneously storing, harvesting, and converting multiple energy modalities for wearable and portable devices. This Account highlights our recent studies on the nanoengineering of c-MOFs on the surface of cellulose nanofibers (CNFs) through interfacial synthesis, enabling the fabrication of freestanding, flexible, and mechanically robust CNF@c-MOF nanopapers, as well as their applications in energy harvesting, conversion, and storage. We discuss the fundamental principles governing the interfacial growth of c-MOF nanostructures on flexible nanofibrous substrates, including the regulation of metal–ligand coordination and interfacial chemical interactions that govern hierarchical assembly toward functional flexible architectures. This Account also summarizes recent advances in the fabrication of flexible c-MOF films, covering representative preparation strategies, structural design approaches, and their unique roles in emerging energy technologies. Future progress in metal center selection, ligand electronic modulation, pore architecture optimization, interface engineering, and composite integration will further improve electron–ion transport, mechanical durability, and device-level compatibility. By combining flexible substrates with multiscale hierarchical structures, flexible c-MOF films can establish interconnected transport networks and adaptive function
{"title":"Interface-Engineered Flexible Conductive Metal–Organic Framework Films for Multimodal Energy Applications","authors":"Shengyang Zhou,Zhixiang Dai,Jingyu Cao,Chao Xu","doi":"10.1021/accountsmr.6c00177","DOIUrl":"https://doi.org/10.1021/accountsmr.6c00177","url":null,"abstract":"Conductive metal–organic frameworks (c-MOFs) represent a distinct class of porous conductive materials. Compared with conventional MOFs, c-MOFs integrate intrinsically high electrical conductivity with a high surface area and an ordered porous structure, enabling efficient electron and ion transport. Engineering c-MOFs into continuous and flexible films offers a promising strategy for translating their properties into practical devices. Key strategies for film engineering include solution processing, interfacial growth, and chemical vapor deposition, which allow precise control over the film morphology, thickness, and alignment of conductive channels. Thin-film fabrication preserves structural integrity and pore connectivity, enhances interfacial contact, and facilitates device integration, thereby promoting coupled ionic and electronic transport. These properties render c-MOF films suitable for multimodal energy transformation. In energy storage, their mechanical compliance, flexibility, and high porosity enable conformal integration with deformable and wearable devices while maintaining rapid charge transport and long-term cycling stability. In energy harvesting and conversion, their ordered porous networks, tunable electronic structures, and freestanding mechanically flexible architectures enable efficient adaptation to diverse energy inputs, facilitating energy conversion involving electrical, mechanical, chemical, thermal, and optical processes while maintaining the structural integrity under dynamic deformation. This versatility supports the development of integrated systems capable of simultaneously storing, harvesting, and converting multiple energy modalities for wearable and portable devices.\u0000This Account highlights our recent studies on the nanoengineering of c-MOFs on the surface of cellulose nanofibers (CNFs) through interfacial synthesis, enabling the fabrication of freestanding, flexible, and mechanically robust CNF@c-MOF nanopapers, as well as their applications in energy harvesting, conversion, and storage. We discuss the fundamental principles governing the interfacial growth of c-MOF nanostructures on flexible nanofibrous substrates, including the regulation of metal–ligand coordination and interfacial chemical interactions that govern hierarchical assembly toward functional flexible architectures. This Account also summarizes recent advances in the fabrication of flexible c-MOF films, covering representative preparation strategies, structural design approaches, and their unique roles in emerging energy technologies. Future progress in metal center selection, ligand electronic modulation, pore architecture optimization, interface engineering, and composite integration will further improve electron–ion transport, mechanical durability, and device-level compatibility. By combining flexible substrates with multiscale hierarchical structures, flexible c-MOF films can establish interconnected transport networks and adaptive function","PeriodicalId":72040,"journal":{"name":"Accounts of materials research","volume":"34 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2026-10-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149248511","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-10-23Epub Date: 2026-09-25DOI: 10.1021/accountsmr.6c00190
Mahni Fatahi, Eli Zysman-Colman
<p>Organiclight-emitting diodes (OLEDs) have becomea cornerstonetechnology in modern displays, yet their dominant manufacturing route,vacuum deposition (VD), remains cost-intensive and intrinsically wasteful.Solution processing (SP) offers an attractive alternative becauseit enables high-throughput fabrication, reduced material loss, andcompatibility with large-area and flexible substrates. Organic thermallyactivated delayed fluorescence (TADF) emitters are uniquely positionedfor SP-OLEDs, as they can harvest both singlet and triplet excitons,providing a route to near-unity device internal quantum efficiency,without the need for scarce heavy metals. The key challenge, however,is that the performance of SP TADF OLEDs still lags behind VD devicesin both maximum external quantum efficiency and efficiency roll-off.These performance gaps originate from SP-specific constraints suchas unoptimized film morphology, aggregation-caused quenching (ACQ),limited control over transition dipole orientation, and charge imbalancein multilayer stacks. Consequently, closing the VD–SP performancedivide requires coordinated progress in molecular engineering anddevice engineering.</p><p>This Account summarizes recent materials-designstrategies forhigh-performance SP TADF OLEDs, with emphasis on multiresonant TADF(MR-TADF) emitters and TADF dendrimers. Small-molecule donor–acceptor(D-A) TADF emitters, though compatible for SP-OLEDs, often show broademission resulting from their emissive long-range charge-transfer(LRCT) states and large reorganization energies, compromising colorpurity. MR-TADF emitters address this limitation, providing narrowbandemission from a short-range charge-transfer (SRCT) state resultingfrom the alternating HOMO/LUMO density on adjacent atoms. Yet evenstate-of-the-art MR-TADF materials that deliver outstanding VD-OLEDperformance yield SP-OLEDs showing a marked drop in performance, evidencingthat processing-induced disorder and bimolecular quenching becomedominant in these devices. We therefore highlight how contemporaryMR-TADF emitter design has shifted beyond solubility improvementstoward deliberate control of film-state organization (e.g., liquid-crystallineself-assembly to induce preferential horizontal dipole orientationand improve outcoupling) and excited-state kinetics (e.g., multichromophorecoupling and intramolecular FRET concepts to accelerate effectivetriplet harvesting and reduce roll-off while retaining narrow emission).</p><p>In parallel, TADF dendrimers combine the high solubility and film-formingability of polymers with the high purities possible with small molecules.This leads to SP devices showing comparable performance to VD ones.We discuss how dendrimer design has progressed from early low-performingprototype devices to SP-OLEDs showing <em>EQE</em><sub>max</sub> approaching 30%. We discuss how dendrimer design provides additionallevers to modulate charge balance and efficiency roll-off. Importantly,dendrimers have also proven
{"title":"Closing the Gap: Multiresonant TADF Emitters and TADF Dendrimers in Solution-Processed OLEDs","authors":"Mahni Fatahi, Eli Zysman-Colman","doi":"10.1021/accountsmr.6c00190","DOIUrl":"10.1021/accountsmr.6c00190","url":null,"abstract":"<p>Organiclight-emitting diodes (OLEDs) have becomea cornerstonetechnology in modern displays, yet their dominant manufacturing route,vacuum deposition (VD), remains cost-intensive and intrinsically wasteful.Solution processing (SP) offers an attractive alternative becauseit enables high-throughput fabrication, reduced material loss, andcompatibility with large-area and flexible substrates. Organic thermallyactivated delayed fluorescence (TADF) emitters are uniquely positionedfor SP-OLEDs, as they can harvest both singlet and triplet excitons,providing a route to near-unity device internal quantum efficiency,without the need for scarce heavy metals. The key challenge, however,is that the performance of SP TADF OLEDs still lags behind VD devicesin both maximum external quantum efficiency and efficiency roll-off.These performance gaps originate from SP-specific constraints suchas unoptimized film morphology, aggregation-caused quenching (ACQ),limited control over transition dipole orientation, and charge imbalancein multilayer stacks. Consequently, closing the VD–SP performancedivide requires coordinated progress in molecular engineering anddevice engineering.</p><p>This Account summarizes recent materials-designstrategies forhigh-performance SP TADF OLEDs, with emphasis on multiresonant TADF(MR-TADF) emitters and TADF dendrimers. Small-molecule donor–acceptor(D-A) TADF emitters, though compatible for SP-OLEDs, often show broademission resulting from their emissive long-range charge-transfer(LRCT) states and large reorganization energies, compromising colorpurity. MR-TADF emitters address this limitation, providing narrowbandemission from a short-range charge-transfer (SRCT) state resultingfrom the alternating HOMO/LUMO density on adjacent atoms. Yet evenstate-of-the-art MR-TADF materials that deliver outstanding VD-OLEDperformance yield SP-OLEDs showing a marked drop in performance, evidencingthat processing-induced disorder and bimolecular quenching becomedominant in these devices. We therefore highlight how contemporaryMR-TADF emitter design has shifted beyond solubility improvementstoward deliberate control of film-state organization (e.g., liquid-crystallineself-assembly to induce preferential horizontal dipole orientationand improve outcoupling) and excited-state kinetics (e.g., multichromophorecoupling and intramolecular FRET concepts to accelerate effectivetriplet harvesting and reduce roll-off while retaining narrow emission).</p><p>In parallel, TADF dendrimers combine the high solubility and film-formingability of polymers with the high purities possible with small molecules.This leads to SP devices showing comparable performance to VD ones.We discuss how dendrimer design has progressed from early low-performingprototype devices to SP-OLEDs showing <em>EQE</em><sub>max</sub> approaching 30%. We discuss how dendrimer design provides additionallevers to modulate charge balance and efficiency roll-off. Importantly,dendrimers have also proven","PeriodicalId":72040,"journal":{"name":"Accounts of materials research","volume":"7 10","pages":"1103–1116"},"PeriodicalIF":14.1,"publicationDate":"2026-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149050001","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
<p>Cell populationsare inherentlyheterogeneous, and the molecularmechanisms that govern cellular plasticity and fate operate acrossbroad spatial and temporal scales. Early signaling events emerge withinseconds to minutes, whereas phenotypic transitions associated withdifferentiation, adaptation, and disease progression may unfold overhours, days, or longer. Elucidating these dynamic processes requiresmolecular imaging tools capable of quantitatively monitoring biochemicalevents with high spatial resolution, temporal precision, and molecularspecificity in living systems. However, achieving this goal demandsthe integration of multiple design principles that are rarely realizedwithin a single molecular platform. Therefore, the development ofsuch tools remains a central challenge in chemical biology becausemolecular recognition, fluorescence signaling, organelle targeting,and photostability must be integrated within a single molecular architecture.In this Account, we present a historical overview of the evolutionof our unique molecular imaging toolbox, tracing its development from <em>fundamental studies</em> of molecular recognition in artificialsystems to multiplex visualization of organelle dynamics in livingcells, and ultimately to their successful translation into <em>bioimaging probes</em>. Our early efforts established how <em>hydrogen-bonding interactions at artificial lipid membrane interfaces</em> can be exploited to <em>enhance biomolecular recognition</em> under aqueous conditions. These studies further revealed that tuningmembrane mechanical properties provides a powerful strategy for <em>discriminating structurally similar nucleotide targets</em> andregulating selective molecular recognition. The principles derivedfrom these artificial systems were subsequently extended to fluorescencesensing platforms for recognition of biologically relevant analytes.Building upon these molecular recognition strategies, we developedheteroatom-containing <em>π</em>-conjugated fluorophoresin which <em>phosphorus, sulfur, and nitrogen elements</em> were strategically incorporated into <em>ladder-type π-conjugated compounds</em> to modulate electronic structure, fluorescenceproperties, and bioimaging performance. Systematic molecular engineeringtransformed these fluorophores from <em>intracellular ion sensors</em> into highly selective <em>organelle-targeting probes</em> and, ultimately, <em>multiplex imaging platforms</em> capableof simultaneously visualizing dynamic interactions among multiplesubcellular compartments. Importantly, heteroatom engineering alsoenabled exceptional photostability, allowing long-term imaging ofgradual cellular transitions that are inaccessible with conventionalprobes. A recurring theme throughout this work is the rational integrationof molecular components to bridge chemical structure and biologicalfunction. Through precise tuning of fluorophore scaffolds, linkerarchitectures, molecular recognition motifs, and organelle-target
{"title":"Ladder-Type π-Conjugated Heteroatom-Reinforced Nanoarchitectonics: Transformative Materials for Imaging of Cellular Components","authors":"Linawati Sutrisno, Masayasu Taki, Katsuhiko Ariga, Shigehiro Yamaguchi","doi":"10.1021/accountsmr.6c00184","DOIUrl":"10.1021/accountsmr.6c00184","url":null,"abstract":"<p>Cell populationsare inherentlyheterogeneous, and the molecularmechanisms that govern cellular plasticity and fate operate acrossbroad spatial and temporal scales. Early signaling events emerge withinseconds to minutes, whereas phenotypic transitions associated withdifferentiation, adaptation, and disease progression may unfold overhours, days, or longer. Elucidating these dynamic processes requiresmolecular imaging tools capable of quantitatively monitoring biochemicalevents with high spatial resolution, temporal precision, and molecularspecificity in living systems. However, achieving this goal demandsthe integration of multiple design principles that are rarely realizedwithin a single molecular platform. Therefore, the development ofsuch tools remains a central challenge in chemical biology becausemolecular recognition, fluorescence signaling, organelle targeting,and photostability must be integrated within a single molecular architecture.In this Account, we present a historical overview of the evolutionof our unique molecular imaging toolbox, tracing its development from <em>fundamental studies</em> of molecular recognition in artificialsystems to multiplex visualization of organelle dynamics in livingcells, and ultimately to their successful translation into <em>bioimaging probes</em>. Our early efforts established how <em>hydrogen-bonding interactions at artificial lipid membrane interfaces</em> can be exploited to <em>enhance biomolecular recognition</em> under aqueous conditions. These studies further revealed that tuningmembrane mechanical properties provides a powerful strategy for <em>discriminating structurally similar nucleotide targets</em> andregulating selective molecular recognition. The principles derivedfrom these artificial systems were subsequently extended to fluorescencesensing platforms for recognition of biologically relevant analytes.Building upon these molecular recognition strategies, we developedheteroatom-containing <em>π</em>-conjugated fluorophoresin which <em>phosphorus, sulfur, and nitrogen elements</em> were strategically incorporated into <em>ladder-type π-conjugated compounds</em> to modulate electronic structure, fluorescenceproperties, and bioimaging performance. Systematic molecular engineeringtransformed these fluorophores from <em>intracellular ion sensors</em> into highly selective <em>organelle-targeting probes</em> and, ultimately, <em>multiplex imaging platforms</em> capableof simultaneously visualizing dynamic interactions among multiplesubcellular compartments. Importantly, heteroatom engineering alsoenabled exceptional photostability, allowing long-term imaging ofgradual cellular transitions that are inaccessible with conventionalprobes. A recurring theme throughout this work is the rational integrationof molecular components to bridge chemical structure and biologicalfunction. Through precise tuning of fluorophore scaffolds, linkerarchitectures, molecular recognition motifs, and organelle-target","PeriodicalId":72040,"journal":{"name":"Accounts of materials research","volume":"7 10","pages":"1074–1088"},"PeriodicalIF":14.1,"publicationDate":"2026-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149013709","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-10-23Epub Date: 2026-09-07DOI: 10.1021/accountsmr.6c00197
Yanuo Zhu, Hanlin Gan, Yuguang Ma, Qinglin Jiang
<p>Organic ferromagnetic semiconductors(OFMS), which would unitelong-range spin order with semiconducting charge transport in a purelyorganic lattice, offer a potential pathway to transcend the limitsof Moore’s law. Yet the field has long faced three coupledobstacles. First, the Curie temperatures of reported systems remainfar below room temperature (<10 K), because intermolecular ferromagneticcoupling is weaker than ambient thermal fluctuations. Second, thesaturation magnetization is extremely low in the few systems thatorder near room temperature (∼10<sup>–3</sup> emu g<sup>–1</sup>): only a small fraction of radicals (<1%) adoptferromagnetic configurations, while most remain nonferromagnetic.Third, charge transport is largely absent, as radical spins are typicallylocalized and intermolecular transport pathways remain underdeveloped.Underlying all three is a single gap: the absence of a mechanisticunderstanding linking aggregation structure to intermolecular spincoupling.</p><p>This Account recounts, in the order it unfolded, howour groupconfronted that gap. Working on rylene diimide-based semiconductors─chosenfor their large conjugated cores, tunable substitution, and relativelystable anion radicals─we developed an ionization-induced reconstructionstrategy that, unexpectedly, produced room-temperature ferromagnetismin perylene diimide radical aggregates, with a saturation magnetizationexceeding 1 emu g<sup>–1</sup>. Although this corresponds toonly ∼8% of the theoretical maximum, it already exceeds previouslyreported values by 3 orders of magnitude. After impurity-driven artifactswere excluded, orbital-resolved spectroscopy confirmed that the magnetismarises from spin-polarized π electrons. The ferromagnetism,however, appeared only within an exceptionally narrow processing window,which drove us to ask how aggregation structure governs spin coupling.Using single-crystal, molecular-cluster, and periodic models, we establishedthat ferromagnetism requires a specific combination of intermoleculartwist and slip that suppresses anti-ferromagnetic exchange, an effectamplified cooperatively in many-body assemblies. Exchange-couplingmaps computed as functions of the π-π distance, twistangle, and slip displacement further translate this geometric criterioninto a first-generation quantitative design diagram for rylene diimideradical assemblies. Crucially, this understanding revealed that theprincipal obstacle was not molecular but a processing conflict: insolution, radical generation and ordered assembly are inseparable.We therefore decoupled the two through a topochemical reduction strategyand obtained OFMS films with a room-temperature saturation magnetizationexceeding 10 emu g<sup>–1</sup> (∼73% of the theoreticalmaximum), 4 orders of magnitude above previously reported values,together with a conductivity of 1.05 S cm<sup>–1</sup>.</p><p>Looking back across these studies, we distill a multiscale structure-spin-functionframework: SOMO delocalizati
有机铁磁半导体（OFMS）将在纯有机晶格中把远距离自旋有序与半导体电荷输运结合起来，为超越摩尔定律的极限提供了一条潜在的途径。然而，该领域长期以来一直面临着三个双重障碍。首先，所报道的系统的居里温度仍然远低于室温（<10 K），因为分子间铁磁耦合弱于环境热波动。其次，在少数接近室温（~ 10-3 emu g-1）的体系中，饱和磁化强度极低：只有一小部分自由基（<1%）采用铁磁性构型，而大多数自由基仍是非铁磁性的。第三，电荷输运在很大程度上是不存在的，因为自由基自旋通常是局部的，分子间的输运途径仍然不发达。这三者的基础是一个单一的缺口：缺乏将聚集结构与分子间旋耦合联系起来的机制理解。本帐户按照展开的顺序，叙述了我们小组如何面对这一差距。研究基于二甲苯二亚胺的半导体──因其大的共轭核、可调的取代和相对稳定的阴离子自由基而被选中──我们开发了一种电离诱导的重建策略，出乎意料地，产生了室温下的铁磁二亚胺二亚胺自由基聚集体，饱和磁化强度超过1emu g-1。虽然这只相当于理论最大值的8%，但它已经超过了先前报道的3个数量级。在排除杂质驱动的伪影后，轨道分辨光谱证实了自旋极化π电子的磁性。然而，铁磁性只出现在一个非常狭窄的处理窗口内，这促使我们问聚集结构如何控制自旋耦合。通过使用单晶、分子簇和周期模型，我们发现铁磁性需要分子间扭曲和滑移的特定组合来抑制反铁磁性交换，而反铁磁性交换在多体组合中被有效地放大。交换耦合图作为π-π距离，扭转角和滑移位移的函数计算，进一步将该几何准则转化为第一代二甲苯双圆柱组件的定量设计图表。至关重要的是，这种理解揭示了主要的障碍不是分子，而是加工冲突：不溶，自由基生成和有序组装是不可分割的。因此，我们通过拓扑化学还原策略将两者解耦，并获得室温饱和磁化超过10 emu g-1（理论最大值的约73%）的OFMS薄膜，比先前报道的值高4个数量级，同时电导率为1.05 S cm-1。回顾这些研究，我们提取了一个多尺度结构-自旋功能框架：分子水平的SOMO离域设置了可用的交换通道，聚集水平的扭转和滑移选择了反铁磁和铁磁耦合，加工水平的组装解耦产生决定了有多少自旋最终加入有序网络。我们希望这些见解将刺激有机自旋材料的进一步探索，并加速其向自旋电子器件的发展。
{"title":"Aggregation-Controlled Spin Coupling in Rylene Diimide-Based Ferromagnetic Semiconductors","authors":"Yanuo Zhu, Hanlin Gan, Yuguang Ma, Qinglin Jiang","doi":"10.1021/accountsmr.6c00197","DOIUrl":"https://doi.org/10.1021/accountsmr.6c00197","url":null,"abstract":"<p>Organic ferromagnetic semiconductors(OFMS), which would unitelong-range spin order with semiconducting charge transport in a purelyorganic lattice, offer a potential pathway to transcend the limitsof Moore’s law. Yet the field has long faced three coupledobstacles. First, the Curie temperatures of reported systems remainfar below room temperature (<10 K), because intermolecular ferromagneticcoupling is weaker than ambient thermal fluctuations. Second, thesaturation magnetization is extremely low in the few systems thatorder near room temperature (∼10<sup>–3</sup> emu g<sup>–1</sup>): only a small fraction of radicals (<1%) adoptferromagnetic configurations, while most remain nonferromagnetic.Third, charge transport is largely absent, as radical spins are typicallylocalized and intermolecular transport pathways remain underdeveloped.Underlying all three is a single gap: the absence of a mechanisticunderstanding linking aggregation structure to intermolecular spincoupling.</p><p>This Account recounts, in the order it unfolded, howour groupconfronted that gap. Working on rylene diimide-based semiconductors─chosenfor their large conjugated cores, tunable substitution, and relativelystable anion radicals─we developed an ionization-induced reconstructionstrategy that, unexpectedly, produced room-temperature ferromagnetismin perylene diimide radical aggregates, with a saturation magnetizationexceeding 1 emu g<sup>–1</sup>. Although this corresponds toonly ∼8% of the theoretical maximum, it already exceeds previouslyreported values by 3 orders of magnitude. After impurity-driven artifactswere excluded, orbital-resolved spectroscopy confirmed that the magnetismarises from spin-polarized π electrons. The ferromagnetism,however, appeared only within an exceptionally narrow processing window,which drove us to ask how aggregation structure governs spin coupling.Using single-crystal, molecular-cluster, and periodic models, we establishedthat ferromagnetism requires a specific combination of intermoleculartwist and slip that suppresses anti-ferromagnetic exchange, an effectamplified cooperatively in many-body assemblies. Exchange-couplingmaps computed as functions of the π-π distance, twistangle, and slip displacement further translate this geometric criterioninto a first-generation quantitative design diagram for rylene diimideradical assemblies. Crucially, this understanding revealed that theprincipal obstacle was not molecular but a processing conflict: insolution, radical generation and ordered assembly are inseparable.We therefore decoupled the two through a topochemical reduction strategyand obtained OFMS films with a room-temperature saturation magnetizationexceeding 10 emu g<sup>–1</sup> (∼73% of the theoreticalmaximum), 4 orders of magnitude above previously reported values,together with a conductivity of 1.05 S cm<sup>–1</sup>.</p><p>Looking back across these studies, we distill a multiscale structure-spin-functionframework: SOMO delocalizati","PeriodicalId":72040,"journal":{"name":"Accounts of materials research","volume":"7 10","pages":"1117–1130"},"PeriodicalIF":14.1,"publicationDate":"2026-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149233515","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-10-23Epub Date: 2026-09-24DOI: 10.1021/accountsmr.6c00183
Menghan Shang, Tingting Sun, Vladimir G. Kytin, Vladimir A. Kulbachinskii, Lianjun Wang, Wan Jiang
<p>Although maximizing the thermoelectricfigure of merit (<em>zT</em>) has long been the central objectivein thermoelectricresearch, our studies reveal that high intrinsic material performancealone cannot guarantee a stable and efficient thermoelectric outputin practical operating environments. During long-term device operation,interfacial degradation, elemental interdiffusion, thermomechanicalmismatch, and contact instability frequently induce severe performancedeterioration, indicating that practical applications require notonly high-performance materials but also stable electrical, thermal,and mechanical integration across the entire device architecture.</p><p>This evolution from material-centered optimization toward system-leveldesign has become increasingly important with the emergence of newapplication scenarios, particularly wearable electronics. Unlike conventionalwaste-heat recovery systems with large and stable temperature gradients,wearable thermoelectrics work at soft human–device interfacesunder ultralow, spatially heterogeneous and dynamically fluctuatingthermal conditions. In such working scenarios, thermoelectric performanceis no longer determined merely by intrinsic material efficiency, whileeffective heat utilization, interfacial thermal contact, mechanicaladaptability and stable output become equally essential. In this context,wearable thermoelectrics can be regarded as an extension of thermoelectrictechnology toward application-specific device architectures, wherethe optimization of material properties is coupled with interfacialengineering, heat utilization, and mechanical integration to meetthe stringent requirements of human-centered energy harvesting.</p><p>Driven by these demands, our research contributions have progressivelyexpanded in two interconnected directions. The first focused on developinghigh-performance and operationally stable traditional thermoelectricsystems through the coordinated regulation of carrier transport, phononscattering, interfacial diffusion, and module reliability. The secondextended thermoelectric system toward wearable applications requiresthat materials and devices simultaneously maintain energy conversioncapability, mechanical deformability, and stable thermal contact undercontinuous deformation and dynamic thermal environments.</p><p>ThisAccount first summarizes our progress in developing high-performancebulk thermoelectric materials and a stable device output. By adoptingcarbon modification, elemental doping, diffusion barrier construction,and optimized module design, we developed multiple strategies to optimizeelectrical transport, suppress thermal conduction, stabilize microstructures,and reduce interfacial electrical loss simultaneously.</p><p>We furtherdiscuss the advancement of flexible thermoelectric systemsdriven by wearable applications. Flexible thermoelectric devices arefabricated via heterogeneous interface engineering, printing techniques,and structural optimization to balance
{"title":"Thermoelectric Performance Optimization toward Practical and Wearable Applications","authors":"Menghan Shang, Tingting Sun, Vladimir G. Kytin, Vladimir A. Kulbachinskii, Lianjun Wang, Wan Jiang","doi":"10.1021/accountsmr.6c00183","DOIUrl":"10.1021/accountsmr.6c00183","url":null,"abstract":"<p>Although maximizing the thermoelectricfigure of merit (<em>zT</em>) has long been the central objectivein thermoelectricresearch, our studies reveal that high intrinsic material performancealone cannot guarantee a stable and efficient thermoelectric outputin practical operating environments. During long-term device operation,interfacial degradation, elemental interdiffusion, thermomechanicalmismatch, and contact instability frequently induce severe performancedeterioration, indicating that practical applications require notonly high-performance materials but also stable electrical, thermal,and mechanical integration across the entire device architecture.</p><p>This evolution from material-centered optimization toward system-leveldesign has become increasingly important with the emergence of newapplication scenarios, particularly wearable electronics. Unlike conventionalwaste-heat recovery systems with large and stable temperature gradients,wearable thermoelectrics work at soft human–device interfacesunder ultralow, spatially heterogeneous and dynamically fluctuatingthermal conditions. In such working scenarios, thermoelectric performanceis no longer determined merely by intrinsic material efficiency, whileeffective heat utilization, interfacial thermal contact, mechanicaladaptability and stable output become equally essential. In this context,wearable thermoelectrics can be regarded as an extension of thermoelectrictechnology toward application-specific device architectures, wherethe optimization of material properties is coupled with interfacialengineering, heat utilization, and mechanical integration to meetthe stringent requirements of human-centered energy harvesting.</p><p>Driven by these demands, our research contributions have progressivelyexpanded in two interconnected directions. The first focused on developinghigh-performance and operationally stable traditional thermoelectricsystems through the coordinated regulation of carrier transport, phononscattering, interfacial diffusion, and module reliability. The secondextended thermoelectric system toward wearable applications requiresthat materials and devices simultaneously maintain energy conversioncapability, mechanical deformability, and stable thermal contact undercontinuous deformation and dynamic thermal environments.</p><p>ThisAccount first summarizes our progress in developing high-performancebulk thermoelectric materials and a stable device output. By adoptingcarbon modification, elemental doping, diffusion barrier construction,and optimized module design, we developed multiple strategies to optimizeelectrical transport, suppress thermal conduction, stabilize microstructures,and reduce interfacial electrical loss simultaneously.</p><p>We furtherdiscuss the advancement of flexible thermoelectric systemsdriven by wearable applications. Flexible thermoelectric devices arefabricated via heterogeneous interface engineering, printing techniques,and structural optimization to balance ","PeriodicalId":72040,"journal":{"name":"Accounts of materials research","volume":"7 10","pages":"1057–1073"},"PeriodicalIF":14.1,"publicationDate":"2026-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149050003","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-10-23DOI: 10.1021/accountsmr.6c00138
Jinhua Li,Jiawei Liu,Yongxin Pan
Magnetotactic bacteria (MTB) are prokaryotes that biomineralize membrane-bound intracellular magnetite (Fe3O4) or greigite (Fe3S4) nanocrystals, termed magnetosomes. These crystals commonly form chains that function as nanoscale compass needles. As naturally evolved living magnetic nanomaterial systems, MTB connect intracellular biomineralization, magnetic-field-guided behavior, microbial ecology, geological recording, and biomimetic materials design. Their hierarchical magnetosome architecture couples weak geomagnetic fields to cellular magnetic torque, directed motility, and redox-niche positioning, while preserved magnetosomes can enter sedimentary records as magnetofossils. This Account traces MTB from modern cells to ancient rocks and engineered materials. We first show how correlative single-cell microscopy, sequencing, and magnetic analyses link uncultured lineages with cell morphology, magnetosome crystal habit, chain architecture, genomic background, and magnetic properties, extending MTB research beyond a few cultivable models. These studies reveal that magnetosome biomineralization is genetically constrained yet environmentally responsive, providing a reference framework for magnetofossil interpretation and biomimetic magnetic-material design. We next extend the view of MTB beyond magnetosome production. Many MTB also accumulate nonmagnetic mineral and storage phases containing sulfur, phosphorus, silicon, carbonates, and trace metals. Their coexistence with magnetosomes indicates that magnetic navigation is embedded within broader cellular processes involving redox metabolism, nutrient storage, metal homeostasis, and environmental adaptation. MTB can therefore be viewed as intracellular biogeochemical reactors at aquatic redox interfaces, where geomagnetic-field-guided movement may facilitate repeated access to separated oxidants and reductants. Magnetosomal magnetic particles are also geologically important as nanoscale magnetic fossils. When sufficiently preserved, magnetofossils can constitute a “triple archive” of paleomagnetic information, paleoenvironmental redox conditions, and ancient microbial activity. Realizing this potential requires quantitative, carrier-resolved identification in complex magnetic mineral assemblages. We therefore emphasize workflows combining rock magnetism with microscopy, crystallography, nanoscale chemical analysis, and calibration against modern MTB to distinguish biogenic signals from detrital, authigenic, and diagenetic overprints and assess magnetofossil preservation. Finally, we frame MTB and magnetosome systems as a cross-scale platform for functional magnetic materials. At the particle scale, magnetosome core chemistry, crystal morphology, and membrane interfaces can be modified through controlled cultivation, chemical substitution, genetic programming, and heterologous biosynthesis. At the chain scale, regulated particle size, spacing, alignment, and dipolar interactions generate collective an
{"title":"Magnetotactic Bacteria at the Earth-Life-Materials Interface","authors":"Jinhua Li,Jiawei Liu,Yongxin Pan","doi":"10.1021/accountsmr.6c00138","DOIUrl":"https://doi.org/10.1021/accountsmr.6c00138","url":null,"abstract":"Magnetotactic bacteria (MTB) are prokaryotes that biomineralize membrane-bound intracellular magnetite (Fe3O4) or greigite (Fe3S4) nanocrystals, termed magnetosomes. These crystals commonly form chains that function as nanoscale compass needles. As naturally evolved living magnetic nanomaterial systems, MTB connect intracellular biomineralization, magnetic-field-guided behavior, microbial ecology, geological recording, and biomimetic materials design. Their hierarchical magnetosome architecture couples weak geomagnetic fields to cellular magnetic torque, directed motility, and redox-niche positioning, while preserved magnetosomes can enter sedimentary records as magnetofossils. This Account traces MTB from modern cells to ancient rocks and engineered materials. We first show how correlative single-cell microscopy, sequencing, and magnetic analyses link uncultured lineages with cell morphology, magnetosome crystal habit, chain architecture, genomic background, and magnetic properties, extending MTB research beyond a few cultivable models. These studies reveal that magnetosome biomineralization is genetically constrained yet environmentally responsive, providing a reference framework for magnetofossil interpretation and biomimetic magnetic-material design. We next extend the view of MTB beyond magnetosome production. Many MTB also accumulate nonmagnetic mineral and storage phases containing sulfur, phosphorus, silicon, carbonates, and trace metals. Their coexistence with magnetosomes indicates that magnetic navigation is embedded within broader cellular processes involving redox metabolism, nutrient storage, metal homeostasis, and environmental adaptation. MTB can therefore be viewed as intracellular biogeochemical reactors at aquatic redox interfaces, where geomagnetic-field-guided movement may facilitate repeated access to separated oxidants and reductants. Magnetosomal magnetic particles are also geologically important as nanoscale magnetic fossils. When sufficiently preserved, magnetofossils can constitute a “triple archive” of paleomagnetic information, paleoenvironmental redox conditions, and ancient microbial activity. Realizing this potential requires quantitative, carrier-resolved identification in complex magnetic mineral assemblages. We therefore emphasize workflows combining rock magnetism with microscopy, crystallography, nanoscale chemical analysis, and calibration against modern MTB to distinguish biogenic signals from detrital, authigenic, and diagenetic overprints and assess magnetofossil preservation. Finally, we frame MTB and magnetosome systems as a cross-scale platform for functional magnetic materials. At the particle scale, magnetosome core chemistry, crystal morphology, and membrane interfaces can be modified through controlled cultivation, chemical substitution, genetic programming, and heterologous biosynthesis. At the chain scale, regulated particle size, spacing, alignment, and dipolar interactions generate collective an","PeriodicalId":72040,"journal":{"name":"Accounts of materials research","volume":"23 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2026-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149241561","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-10-23Epub Date: 2026-09-01DOI: 10.1021/accountsmr.6c00116
Rong Lin, Minghao Wan, Yanglong Hou, Shengcai Zhu
<p>The transformation of graphiteinto cubic diamond (CD) or hexagonaldiamond (HD) under high pressure represents a prototypical multipathwaysolid-state phase transition. However, the microscopic origin of phaseselectivity remains unclear, and whether HD can exist as a distinctcrystalline phase has long been a subject of ongoing debate. Althoughconventional theoretical frameworks based on thermodynamic stabilityand static energy barriers provide important insights into the dominantformation of CD, they fail to adequately describe the nonequilibriumtransformation kinetics under high-pressure high-temperature (HPHT)conditions and complex stress states and, thus, exhibit fundamentallimitations in accounting for the formation of HD in partially transformedproducts. To address this critical issue, we have recently combinedtheoretical simulations with experimental validation to propose anew mechanism governing phase selectivity. In this framework, phaseselection is governed not by final-state energetics but by the kineticsof the transformation pathway. This perspective bridges the long-standingdiscrepancy between theoretical predictions and experimental observationsand provides a unified physical picture for the competition betweenCD and HD. Within this kinetic framework, phase selectivity is dictatedby the evolution of stacking sequence and the amplitude of interlayersliding in graphite. Our results show that the formation of CD involveslong-range basal-plane sliding (∼1.03 Å), which reconstructsAB stacking into ABC stacking, whereas HD originates from short-rangesliding (∼0.39 Å) that preserves AB stacking. Consequently,conditions that promote interlayer sliding and bending favor the formationof CD, while those that suppress sliding and maintain AB stackingfavor the formation of HD. These findings provide an atomistic basisfor understanding phase selectivity and highlight the critical roleof transformation kinetics. Guided by this principle, we achievedthe synthesis of fine nano-polycrystalline CD under conditions thatpromote stacking disorder and interlayer sliding (<em>σ</em><sub><em>x</em></sub>, <em>σ</em><sub><em>y</em></sub> > <em>σ</em><sub><em>z</em></sub>) and high-purity bulk HD under martensitic transformationconditions (<em>σ</em><sub><em>z</em></sub> > <em>σ</em><sub><em>x</em></sub>, <em>σ</em><sub><em>y</em></sub>). In this Account, we systematicallysummarize the formation mechanisms and anisotropic growth behaviorof CD, as well as the formation mechanism of HD, and highlight twosynthesis strategies we have developed for producing high-purity bulkHD. These approaches realize indirect and direct transformations underultrahigh-pressure and relatively lower-pressure conditions, respectively,thereby providing evidence that HD is a distinct phase and providingpractical routes for its controlled synthesis. Finally, this kineticframework not only offers new theoretical guidance for the phase-selectivesynthesis of carbon allotropes but al
{"title":"Phase Transition Selectivity of Graphite Under High Pressure","authors":"Rong Lin, Minghao Wan, Yanglong Hou, Shengcai Zhu","doi":"10.1021/accountsmr.6c00116","DOIUrl":"https://doi.org/10.1021/accountsmr.6c00116","url":null,"abstract":"<p>The transformation of graphiteinto cubic diamond (CD) or hexagonaldiamond (HD) under high pressure represents a prototypical multipathwaysolid-state phase transition. However, the microscopic origin of phaseselectivity remains unclear, and whether HD can exist as a distinctcrystalline phase has long been a subject of ongoing debate. Althoughconventional theoretical frameworks based on thermodynamic stabilityand static energy barriers provide important insights into the dominantformation of CD, they fail to adequately describe the nonequilibriumtransformation kinetics under high-pressure high-temperature (HPHT)conditions and complex stress states and, thus, exhibit fundamentallimitations in accounting for the formation of HD in partially transformedproducts. To address this critical issue, we have recently combinedtheoretical simulations with experimental validation to propose anew mechanism governing phase selectivity. In this framework, phaseselection is governed not by final-state energetics but by the kineticsof the transformation pathway. This perspective bridges the long-standingdiscrepancy between theoretical predictions and experimental observationsand provides a unified physical picture for the competition betweenCD and HD. Within this kinetic framework, phase selectivity is dictatedby the evolution of stacking sequence and the amplitude of interlayersliding in graphite. Our results show that the formation of CD involveslong-range basal-plane sliding (∼1.03 Å), which reconstructsAB stacking into ABC stacking, whereas HD originates from short-rangesliding (∼0.39 Å) that preserves AB stacking. Consequently,conditions that promote interlayer sliding and bending favor the formationof CD, while those that suppress sliding and maintain AB stackingfavor the formation of HD. These findings provide an atomistic basisfor understanding phase selectivity and highlight the critical roleof transformation kinetics. Guided by this principle, we achievedthe synthesis of fine nano-polycrystalline CD under conditions thatpromote stacking disorder and interlayer sliding (<em>σ</em><sub><em>x</em></sub>, <em>σ</em><sub><em>y</em></sub> > <em>σ</em><sub><em>z</em></sub>) and high-purity bulk HD under martensitic transformationconditions (<em>σ</em><sub><em>z</em></sub> > <em>σ</em><sub><em>x</em></sub>, <em>σ</em><sub><em>y</em></sub>). In this Account, we systematicallysummarize the formation mechanisms and anisotropic growth behaviorof CD, as well as the formation mechanism of HD, and highlight twosynthesis strategies we have developed for producing high-purity bulkHD. These approaches realize indirect and direct transformations underultrahigh-pressure and relatively lower-pressure conditions, respectively,thereby providing evidence that HD is a distinct phase and providingpractical routes for its controlled synthesis. Finally, this kineticframework not only offers new theoretical guidance for the phase-selectivesynthesis of carbon allotropes but al","PeriodicalId":72040,"journal":{"name":"Accounts of materials research","volume":"7 10","pages":"1047–1056"},"PeriodicalIF":14.1,"publicationDate":"2026-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149233497","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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