Colloid and Polymer Science最新文献

The development of mesoporous hybrid materials with stimuli-responsive pore networks offers a promising platform for controlled release applications. In this study, we synthesize mesoporous silica microcapsules functionalized with poly(N-isopropylacrylamide) (PNIPAM) as thermally gated molecular valves for the controlled delivery of waste soybean cooking oil (WSCO) to rejuvenate aged bitumen. Using an oil-in-water emulsion and sol–gel polymerization, we produce microcapsules with a well-defined core–shell architecture, featuring a WSCO core and a mesoporous silica shell with pore sizes of 10 to 30 nm and a thickness of 100 to 300 nm. PNIPAM is incorporated within the mesopore network via hydrogen bonding between its amide groups and surface silanols, forming spatially distributed polymer domains that act as reversible gates. Below the lower critical solution temperature (LCST) of approximately 32 °C, the hydrated PNIPAM chains expand to block the mesopores, restricting WSCO diffusion. Above the LCST, chain collapse opens the pore networks, enabling rapid release. Franz diffusion cell measurements reveal a temperature-dependent release profile, with 85% cumulative release achieved at 60 °C following first order kinetics, while only 5% is released at − 10 °C with zero order kinetics. When incorporated into aged bitumen at a loading of 5.0 weight%, the microcapsules restore key performance properties, including a 70% recovery in penetration, a 10 °C reduction in softening point, and a 35% to 40% improvement in rutting resistance after activation at service relevant temperatures. This work demonstrates a robust mesoporous hybrid system that integrates pore architecture engineering with thermally responsive gating, providing a sustainable strategy for waste valorization and intelligent infrastructure material design.

This study reports the discovery of novel interfacial phenomena at the gas-liquid interface of rising bubbles in polymeric liquids. These phenomena are characterized by the formation of unique and exotic microstructures that extend from the bottom of the bubble. Experimental observations indicate that the morphology of these microstructures depends strongly on both the viscoelastic properties of the polymeric liquid and the bubble equivalent diameter. Significantly, the stability and complexity of these structures defy classical explanations based purely on surface tension, which would typically favor interface minimization. Instead, our findings highlight the critical role of localized molecular interactions between the gas phase and the polymeric liquid. This study provides new insights into the microscale coupling of polymer dynamics and interfacial physics, suggesting that local molecular interaction can dominate over bulk rheological properties in complex fluid systems.

Water-dispersible polyester (WPET), as an amphiphilic macromolecule, shows significant value in textile sizing applications. However, in alkaline environments, WPET undergoes simultaneous aggregation and hydrolysis, complicating its removal during fabric processing. This study systematically investigates the aggregation and hydrolysis kinetics of WPET with varying -SO₃^- and PEG contents in NaOH solution, along with their interaction mechanisms. By combining DLS, zeta potential, fluorescence spectroscopy, alkali consumption measurements, and product characterization, the interplay between NaOH concentration and WPET molecular structure in regulating solution stability and phase transitions is elucidated. The addition of NaOH triggers a competition for water molecules between the ions and the WPET chains: the strong hydration of Na⁺ and OH^- strips the hydration layer surrounding the sulfonate and PEG segments, exposing the hydrophobic backbones and leading to oligomer aggregation. This hydration‑layer evolution is the microscopic origin of the observed salting‑out effect. The conformational looseness of WPET chains, primarily governed by the sulfonate group content, serves as a key structural parameter: a more extended conformation facilitates NaOH penetration, thereby accelerating both aggregation and hydrolysis. NaOH concentration exhibits a critical threshold (approximately 0.2 M): below this concentration, hydrolysis predominates; above it, strong aggregation inhibits hydrolysis by forming dense aggregates that physically shield ester bonds. These findings provide a mechanistic guideline for practical textile desizing and alkali‑treatment processes, indicating that moderate rather than excessive alkali concentrations are more effective for WPET removal.

This study successfully synthesized a high-purity, nano-sized Al₂O₃/SiO₂ composite material with a high specific surface area and investigated the adsorption performance of novel material based on anionic surfactant, a sodium dodecyl sulfate (SDS)-modified Al₂O₃/SiO₂ nanocomposite for tetracycline (TC) removal from water. The characteristic features of Al₂O₃/SiO₂ nanocomposite were determined via XRD, TEM and EDX methods. Surface modification with the anionic surfactant SDS significantly enhanced TC removal compared to the untreated material due to increased hydrophobicity and improved electrostatic interactions. The optimal adsorption conditions were determined to be an adsorbent dosage of 2 mg/mL, pH 4, a contact time of 120 min and 1 mM NaCl. Under these conditions, SDS-modified Al₂O₃/SiO₂ nanocomposite presented a TC removal efficiency exceeding 95% and an adsorption capacity of approximately 137 mg/g. Freundlich adsorption isotherms model well fitted the adsorption data and the pseudo-second-order was the best kinetic model to describe TC adsorption, indicating that chemisorption dominated this process. Electrostatic attraction and hydrophobic interactions between the SDS-modified surface and TC molecules were key for TC adsorption as shown in zeta potential analyses and FT-IR spectroscopy. A partial desorption of SDS from the nanocomposite surface was why when increasing pH and ionic strength, adsorption capacity witnesses a fall. SDS-modified Al₂O₃/SiO₂ nanocomposite is an efficient and promising adsorbent for tetracycline antibiotics in water.

Graphical Abstract

Recovery of gold from secondary resources has garnered significant attention due to its vital role in the growing information industry. However, understanding the extraction mechanisms and enhancing the efficiency of microemulsions pose considerable challenges. Herein, two w/o microemulsions were formulated using commercial gemini surfactants, namely GC-B (with an amide group) and GC-A (without an amide group), as emulsifiers, supplemented with n-butanol as a cosurfactant, n-heptane as the oil phase, and NaCl solution as the internal phase for the extraction of gold(III) from hydrochloric acid solutions. The results indicated that GC-B microemulsion demonstrated significantly higher extraction efficiencies and was less sensitive to fluctuations in temperature (20 ~ 60 °C), surfactant/cosurfactant concentration (0.05 ~ 0.25 g/0.8 ~ 2.5 mL), and NaCl content (0 ~ 0.2 mol/L) than GC-A microemulsion. This enhanced performance is primarily attributed to the protonation of the amide groups in hydrochloric acid, which imparts a more pronounced positive charge to the microemulsion (evidenced by a higher binding constant of 2.46) and facilitates stronger intermolecular hydrogen bonding interactions. Under optimal conditions (0.05 g surfactant, 3.5 mL heptane, 0.025 mol/L NaCl, a water-emulsion ratio of 8, and 1.2 mL n-butanol), GC-B microemulsion achieved an extraction efficiency exceeding 95%. This study presents a viable approach for designing and selecting surfactants in microemulsion-based extraction processes for gold(III). However, the reuse of surfactants remains an issue that needs to be resolved.

To overcome physical blending limitations in polymer fracturing fluid thickeners, this study proposes a chemical cross-linking strategy based on the Schiff base condensation reaction. The base thickener (WPAM) was synthesized via inverse emulsion polymerization, while dialdehyde-modified cellulose nanofibers (QCNF) were prepared by modifying pristine cellulose nanofibers (CNF). A novel nano-organic composite thickener was subsequently fabricated via chemical cross-linking of WPAM and QCNF. Fourier transform infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM) verified the successful modification of QCNF and its integration into a dense, cross-linked multi-network with WPAM. Rheological evaluations demonstrated that a 1.4 wt% composite solution maintained a viscosity of 53 mPa·s in high-salinity brine (85,000 mg/L). Under a shear rate of 170 s⁻¹ in 8,850 mg/L brine, the fluid exhibited robust shear resistance, retaining viscosities of 56.55 mPa·s and 50.96 mPa·s at 120 °C and 140 °C, respectively. Furthermore, 0.2–0.4 wt% solutions achieved drag reduction rates exceeding 70%. The fluid also demonstrated superior proppant suspension capabilities; the static settling rate was less than 10% after 120 min, and dynamic simulations confirmed efficient proppant transport. Gel breaking tests revealed that adding 0.03 wt% ammonium persulfate at 90 °C reduced the fluid viscosity to 1.88 mPa·s within 2 h. Subsequent core displacement tests indicated minimal permeability damage (12.41%) from the broken fluid. This study offers a promising pathway for developing high-performance thickeners for high-temperature, high-salinity fracturing fluids, demonstrating significant application potential in deep oil and gas reservoir stimulation.

This study investigates the extraction, synthesis, and performance evaluation of a natural surfactant obtained from Sapindus mukorossi extract (SME) and its mixed system with copper oxide nanoparticles (CuO NPs) for surface-active properties. The surface-active properties of the SME-CuO NPs mixed system were compared with those of SME. Preliminary characterization using UV–visible spectroscopy showed a characteristic peak for CuO NPs and the presence of saponin in SME. A Shift in the absorption peak in the SME-CuO NPs mixed system suggests interaction taking place between SME and CuO NPs. The results revealed that the observed enhancement in parameters such as foaming ability, stability, emulsification, viscosity, and pH shows a strong dependence on the surfactant NPs concentration. SME-CuO NPs mixed system showed enhanced emulsification at a concentration range of 5.0×({10}^{-4}) to 4.0×({10}^{-2}) g/cc, higher foaming ability at 2.0×({10}^{-4}) to 2.0×({10}^{-3}) g/cc and increased viscosity at 5.0×({10}^{-3}) to 2.0×({10}^{-2}) g/cc as compared to SME. The critical micelle concentration (CMC) of the SME and SME-CuO NPs mixed system was determined by electrical conductivity, and its value was found to be 1.21×({10}^{-3}) g/cc and 1.86 ×({10}^{-3}) g/cc, respectively. SME-CuO NPs mixed system exhibited a slight increase in CMC as compared to SME, indicating the occurrence of micellization at slightly higher concentration for SME-CuO NPs mixed system. pH results indicated that the SME-CuO NPs mixed system is acidic at a lower concentration range of 3.0×({10}^{-5}) to 3.0×({10}^{-3}) g/cc as compared to SME. These findings demonstrate that the SME-CuO NPs mixed system effectively optimizes micelle formation and surface activity, highlighting its potential for applications in enhanced oil recovery, pharmaceuticals, food, and cosmetic formulations.

Polylactide (PLA) is brittle at ambient temperature and has insufficient barrier properties, which limits its packaging applications. Incorporating metal–organic frameworks offers an effective strategy to overcome these limitations. Zeolitic imidazolate framework-8 (ZIF-8) nanoparticles were synthesized at room temperature and incorporated into PLA matrices via solution casting method to create nanocomposite films. The ZIF-8/PLA composites were characterized using scanning electron microscopy, Fourier-transform infrared spectroscopy, X-ray diffraction, thermogravimetric analysis, mechanical testing, and permeability assessment. The ZIF-8 particles showed a rhombic dodecahedral morphology with an average size of ~ 200 nm and high crystallinity confirmed by XRD. The incorporation of ZIF-8 enhanced the toughness of PLA: elongation at break of the resultant PLA composites increased up to 9.47% at a loading of 0.2 phr of ZIF-8, representing a 2.7-fold improvement over neat PLA. A non-monotonic trend was observed for the barrier properties: the water vapor permeability decreased by up to 57% at 4.0 phr of ZIF-8, whereas the oxygen permeability peaked at six times that of pure PLA at 1.0 phr, respectively. These behaviors are explained by a newly proposed hydrophobicity–pore cooperative permeability model, which considers ZIF-8’s hydrophobicity, nanoporosity, and interfacial compatibility with the polymer matrix. The ZIF-8 modified PLA composites maintained high optical transparency (> 84% at 700 nm) and demonstrated balanced multifunctionality, highlighting their potential in advanced packaging, sensing, and responsive material applications, although the thermal stability decreased slightly owing to the catalytic effects.

Graphical abstract

This study presents a Pickering emulsion-templated strategy to fabricate SiOx/graphite@C composite microcapsules serving as high-performance anodes for lithium-ion batteries. Amphiphilic cellulose nanocrystal/carbon black (CNC/CB) nanohybrids dispersed in the aqueous phase act as solid emulsifiers to stabilize the emulsion droplets. The oil phase contains SiOx and graphite dispersed in a polyphenylene oxide (PPO)/toluene solution. The CNC/CB nanohybrids not only ensure emulsion stability but also contribute to the electrical conductivity of the carbon shell. The SiOx/graphite@C composite microcapsules enable uniform encapsulation of SiOx and graphite, addressing the challenges of low conductivity and volume expansion inherent to SiOx anodes. The main effort of this study lies in the systematic regulation of emulsion formulations (CB concentration, PPO concentration, and SiOx-to-graphite mass ratio) to tailor the microstructure, shell integrity, and electrochemical performance of the obtained anode samples. Optimal formulations yield composite microcapsules with enhanced structural integrity and electrochemical activity, demonstrating the potential of Pickering emulsion-based design for scalable and tunable fabrication of advanced composite anodes.

After long-term water flooding, high-permeability domains in heterogeneous reservoirs are typically characterized by high degrees of oil depletion and high water cut, whereas low-permeability domains retain high oil saturation and low water cut. This contrast further amplifies reservoir heterogeneity and makes it increasingly difficult for chemical flooding to enhance oil recovery (EOR) through balanced displacement. Here, we constructed an in situ emulsification system composed of an associating polymer, surfactant, and salt (APSS) for coupled profile control and oil displacement. The crude-oil emulsification behavior, microstructure and rheology of high-water-content emulsions, seepage characteristics in a 70% water-cut sand-packed plate model, and EOR performance in water-flooded parallel heterogeneous sand-pack models were systematically evaluated. A polyacrylamide/surfactant/salt system (PSS) with comparable apparent viscosity and oil–water interfacial tension was used as the control. The results show that APSS exhibits a distinctive water-cut-responsive emulsification behavior that requires the synergistic action of all three components. In the high-water-content range of 50–90%, APSS forms highly viscous emulsions, whereas under low-water-content conditions it either forms low-viscosity emulsions or does not emulsify. The viscosity of the stable, high-viscosity APSS emulsions is 5 ~ 20 times higher than that of the injected displacing fluid and the crude oil. By contrast, PSS forms only weakly stable emulsions over a narrower water-content range of 40 ~ 60%, with viscosities only 2 ~ 3 times higher than those of the displacing fluid or crude oil. Confocal laser scanning microscopy (CLSM) and rheological measurements of the APSS emulsion at 70% water content reveal the coexistence of spherical oil-in-water droplets and filamentous/strand-like aggregates, giving rise to a multilevel structure and gel-like rheological behavior. In three heterogeneous displacement models with permeability contrasts of 5 ~ 10, APSS not only emulsified and displaced oil efficiently in high-permeability zones while generating substantial flow resistance, but also redirected the displacing fluid toward low-permeability zones. The average total oil recoveries achieved by APSS were 92.2%, 46.2%, and 89.8%, which were markedly higher than the corresponding values for PSS (79.8%, 32.8%, and 32.7%). This water-cut-viscosity-responsive in situ emulsification system provides a new technical strategy and experimental basis for deep fluid diversion and enhanced oil recovery in high-water-cut heterogeneous reservoirs.