MACROMOLECULES
·
2024
·
IF 5.1
Jia Yu Hu,Li Xin Hou,Ao Zhu,Hao Nan Qiu,Zi Rong Zhang,Cong Du,Kunpeng Cui,Qiang Zheng,Zi Liang Wu
Glassy hydrogels with high stiffness and toughness have been developed in recent years by forming dense associative interactions in a gel matrix. There are several reports on forming robust hydrophobic associations with microphase separation during the solvent exchange process to convert elastic organogels to glassy hydrogels. However, the microstructure formation during the solvent exchange process and the mechanism accounting for rubbery-to-glassy transition of the gels remain unclear. In this study, we copolymerize hydrophobic ethylene glycol phenyl ether acrylate and hydrophilic methacrylic acid in dimethyl sulfoxide, followed by solvent exchange with water to form glassy hydrogels with microphase-separated structures. Ultrasmall- and small-angle X-ray scattering measurements are performed on the gel during the solvent exchange process at various temperatures, and structural parameters are ascertained to trace the structural evolution of the gel. A two-stage structural formation mechanism is proposed for the varying microstructure and properties of the gel during the solvent exchange process. At the initial stage, segregation of hydrophobic segments leads to microphase separation that creates a bicontinuous structure with a high-viscosity polymer-rich phase. At the late stage, the polymer-rich phase becomes vitrified, which arrests the microphase separation and produces a glassy hydrogel far from the thermodynamic equilibrium state. The metastability nature of glassy gel can be harnessed to mediate the microstructure and properties by hydrothermal treatment to reactivate the phase separation. This study provides insights into the interaction between microphase separation and vitrification that determines the structure and properties of glassy gels, which will merit the design of high-performance soft materials with phase-separated structures.
研究领域:
材料科学
·
软物质物理
·
高分子化学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED ENERGY
·
2024
·
IF 10.1
Xuebing Liu,Xiaowei Niu,Guoxiong Zhan,Lei Xing,Zhoulan Huang,Bingling Yuan,Yue Peng,Zhen Chen,Junhua Li
Compared with biphasic solvents with blend amines, the mixture of physical solvent, amines and water (ternary solvent) was a promising preparation strategy. Chemical CO 2 absorption with amine-based solvents is a promising route for industrial CO 2 capture, but suffering from intensive heat duty for solvent regeneration. Developing high-performance biphasic solvent and efficient dynamic phase separator is an effective solution. In this study, poly(ethylene glycol) dimethyl ether (NHD) was selected as the separating agent to prepare a biphasic solvent based on a blended amine (Diethylenetriamine (DETA) and N , N -dimethylcyclohexylamine (DMCA) solvent with a screened proportion of DETA: DMCA: NHD: H 2 O of 1:3:4:2. The CO 2 loading of the saturated solvent was 4.6 mol·L −1 , with over 96% of the CO 2 species concentrated in the rich phase, and with low viscosity of 48.60 mPa·s. The maximum desorption rate of CO 2 -saturated solvent was up to 1.68 mmol·min −1 , and it increased by 243% compared to the MEA solvent (30 wt% MEA and 70 wt% water). The intermediates in various phases were identified using NMR to monitor the species changes during phase splitting. The dynamic phase-splitting capacity was first determined using a quasi-two-dimensional separator, and the results revealed that the liquid velocity of the mixed phase had a dominant effect on the separation efficiency. Furthermore, a novel annular phase separator was proposed to achieve efficient phase separation (the relatively rich separation efficiency increased by 13.40% compared to that with the benchmark.) by decreasing the tangential turbulence from the inlet velocity . The time–space distribution of the CO 2 loading was obtained at different operational parameters. In particular, the effect of water content on separation efficiency was investigated to verify the adaptability of biphasic solvents for practical application.
研究领域:
化学工程
·
环境科学
✓ 已验证
DOI
高影响因子
JOURNAL OF POLYMER RESEARCH
·
2021
·Vol. 28
·期 8
·1-10
·
IF 3.097
Yang Bin,Wang Shu-Qing,Chen Qing-Ting,Ding Meng-Ya,Yu Yang-Nan,Pan Yang,Xia Ru,Ge Qian-Qian,Miao Ji-Bin,Qian Jia-Sheng,Chen Peng,Shi You,Tu You-Lei
Thermally-induced phase separation (TIPS) was used to fabricate polyvinylidene fluoride (PVDF) films under different quenching conditions. Temperature gradient fields were in-situ formed inside the films through varying the TIPS quenching temperature, and an enthalpy transformation method (ETM) was adopted to simulate the temperature gradient fields during the TIPS process. Our findings showed that there existed liquid–liquid phase separation (LLPS) even at higher PVDF concentration (e.g., above the monotectic point). The coexistence and competition between liquid–liquid and solid–liquid phase separations were significantly determined by the cooling rate, which helped to explain the formation mechanisms of hierarchical morphologies observed in the final TIPS films. The present work will be of substantial importance to further studies on an industrial tuning of the microstructure and performance of TIPS films through the operational parameter control.
研究领域:
材料科学
·
高分子工程
·
相变研究
✓ 已验证
DOI
高影响因子
CELLULOSE
·
2019
·Vol. 26
·期 6
·3747-3762
·
IF 3.917
Xing Xiao-Yan,Gu Lin,Jin Yu,Sun Rui,Xie Meng-Yun,Wu Qing-Yun
Abstract Cellulose triacetate (CTA) porous membranes were firstly prepared by the combined nonsolvent-thermally induced phase separation (N-TIPS) method. Dimethyl sulfone (DMSO2) and polyethylene glycol (PEG400) were respectively chosen as the TIPS solvent and additive of CTA, while water was used as the NIPS nonsolvent. Their Hansen solubility parameters were analyzed to understand the solution thermodynamics. Detailed investigation was applied on the effects of the polymer concentration, the coagulation bath temperature and the coagulation bath composition on the CTA porous membranes. It is found that both NIPS and TIPS effects simultaneously exist and compete with each other, and further affect the membrane morphology and performance. The NIPS effect can be promoted by lowering the CTA concentration or elevating the coagulation bath temperature, resulting in figure-like macropores and porous top surface. The obtained CTA porous membranes show a water flux as high as 2002.9 ± 55.2 L/m 2 h. On the contrary, the TIPS effect becomes the dominant factor, and leads to the symmetric sponge-like pores, which facilitate to enhance the mechanical properties. Besides, CTA porous membranes present large surface pore size as well as low fraction of figure-like macropores as increasing the DMSO2 content in the coagulation bath. These CTA porous membranes with excellent water permeability and mechanical strength are promising candidates for microfiltration or the porous substrates of thin film composite membranes. Graphical abstract
研究领域:
材料科学
·
膜技术
✓ 已验证
产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2023
·
IF 8.6
Huarong Yu,Siyuan Shangguan,Haiyang Yang,Hongwei Rong,Fangshu Qu
Poly(vinylidene fluoride) (PVDF) is one of the most used membrane materials in the water industries, and the PVDF membrane can be fabricated majorly through non-solvent induced phase separation (NIPS) and thermally induced phase separation (TIPS). The differences in membrane aging of NIPS-PVDF and TIPS-PVDF remain unclear. In this study, the agings of commercially available NIPS-PVDF and TIPS-PVDF membranes were investigated in the pilot-scale MBRs experiment as well as in the batch soaking tests. The raw PVDF powders in different crystalline polymorphs were also subjected to aging tests to examine the relation between PVDF polymorphous structure and aging. The results showed that the NIPS-PVDF membrane experienced more severe aging in the pilot-scale MBR experiment in comparison with the TIPS-PVDF membrane. Acid aging dislodged and eliminated the additives in the membrane, but did not attack the PVDF. NIPS-PVDF membrane was the dominant β PVDF phase, which was more susceptible to dehydrochlorination in alkaline oxide aging. The thin top layer in the asymmetric structure of the NIPS-PVDF membrane resulted in its vulnerability against alkaline oxide aging. The α PVDF phase and the symmetric structure of the TIPS-PVDF membrane contributed to its greater stability in alkaline oxide aging. Overall, the results can provide a basis for selecting a chemical cleaning strategy for PVDF membranes, and for improving the anti-aging characteristics of the PVDF in the membrane fabrication.
研究领域:
环境科学
·
材料科学
✓ 已验证
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2025
·
IF 8.2
Jiao Xu,Zhiwei Wang,Lingyun Wang,Yawen Liu,Xin Chen,Xianxian Wang,Zheqin Dong
3D printing enables the fabrication of complex, customizable biomedical polymer structures. The integration of superhydrophobicity─known for its unique self-cleaning, antibacterial, and anticoagulant properties─can significantly enhance the functionality of 3D-printed polymer in biomedical applications. However, conventional coating-based approaches for imparting superhydrophobicity suffer from poor mechanical stability due to weak adhesion between the coating layer and the substrate. In this study, we present a solvent transfer-induced phase separation (STIPS) strategy to generate robust superhydrophobic surfaces on 3D-printed polymer scaffolds. This approach involves initially swelling the scaffold surface in a good solvent, followed by immersion in a poor solvent to induce phase separation, thereby forming a micro/nanoporous surface layer essential for achieving superhydrophobicity. The resulting superhydrophobic structures are seamlessly integrated with the bulk material, conferring excellent mechanical durability, as demonstrated by tape-peeling and ultrasonication tests. Importantly, unlike conventional coatings that are limited to flat surfaces, the STIPS method is applicable to complex 3D geometries, including the inner surfaces of hollow vascular scaffolds. Notably, the treated superhydrophobic scaffolds exhibited strong resistance to bacterial adhesion and effective anticoagulant performance, attributed to their pronounced water repellency. This simple yet versatile strategy offers a promising route for expanding the biomedical utility of 3D-printed biodegradable scaffolds, particularly in applications requiring reduced microbial contamination, thrombosis prevention, and low protein fouling.
研究领域:
生物医学工程
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材料科学
·
高分子科学
·
表面工程
·
纳米技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF MEMBRANE SCIENCE
·
2024
·
IF 8.4
Yaqi Dong,Haisheng Zhang,Xin Liu,Xinzhao Luo,Yanqiu Wang,Qiang Zhang
Degradable block copolymers are considered as ideal templates to prepare porous membranes with tunable nanostructure. However, most of these templates are hydrophobic and it remains a challenge to make nanoporous and charged membranes using such templates that contain a sacrificial block through phase inversion. Herein, block copolymers poly(ε-caprolactone)- b -poly(4-vinyl pyridine) have served as cross-linkable and degradable templates to prepare porous and dense membranes via non-solvent induced phase separation (NIPS) or solvent evaporation-induced phase separation (SIPS). During NIPS, the prepared membranes showed a dense skin and finger-like or sponge-like sublayer. By controlling the quaternization and degradation of templates, the permeance of pure water and molecular weight cut-off performance tuning were achieved. The above ultrafiltration membranes with well-defined pores exhibited excellent rejection ability towards different dyes based on size exclusion and Donnan effect. Moreover, after being treated with NaOH solution, the membranes fabricated via SIPS showed a unique change from dense to hollow cross-sectional structure, which also demonstrated promising electrodialysis desalination performance and electrodialysis stability.
研究领域:
材料科学
·
环境工程
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2023
·
IF 8.6
Zidong Tan,Yong Zhen,Chang Wei,Xin Jin,Xingbin Li,Gang Fan,XingGuo Luo
In this study, germanium was selectively extracted using an organic phase containing 3% C7-9 hydroxamic acid (YW100), 15% Di(2-ethylhexyl)phosphoric acid (D2EHPA), 35% Tri(octyl-decyl) amine (N235), and 47% kerosene from the Ge-slag sulfuric acid leaching solution. Then, the solution was stripped by the 1 mol/L NH4F solution to obtain a germanium extraction ratio of 99.4% and a stripping ratio of 96.2% after three extraction and stripping stages. The total organic carbon (TOC) was used to characterize the total organic matter amount in the raffinate. Compared to the “YW100 + D2EHPA” extraction system, the “YW100 + D2EHPA + N235” extraction system reduced 80% of the water solubility loss of YW100 and improved the phase separation performance. In addition, the mechanisms of germanium extraction and phase separation improvement were studied. The coordination number of YW100 and germanium is 3, while the coordination number of D2EHPA is 1.
研究领域:
化学工程
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
MACROMOLECULES
·
2016
·
IF 5.554
Wei Xu,Ruoyu Zhang,Wei Liu,Jin Zhu,Xia Dong,Hongxia Guo,Guo-Hua Hu
Shape memory thermoplastic polyurethane (SMTPU) containing isophorone diisocyanate (IPDI) in hard segment has excellent shape recoverability even after large strain deformation. However, the underlying mechanism of shape recovery remains unclear. In this study, 1,4-phenylene diisocyanate (PPDI) in the polyurethane is gradually substituted by IPDI, and multiscale effects are examined by normal and dichroic Fourier transform infrared spectroscopy (FTIR), small-angle X-ray scattering (SAXS), single-molecule force spectroscopy (SMFS), and mechanical test. Contradictory to the traditional conclusion, the degree of microphase separation decreases as the content of IPDI increases, while the macroscopic shape recoverability is largely improved. With dichroic FTIR and SAXS, we find that the morphology of hard phases changed from lamellar-like to fibrillar-like, which is more stable under stretching. SMFS experiments discover that IPDI could increase the elasticity of polymer chain and could endow the hard phases with “elastic” under stress. With these two factors, we are able to explain the high recoverability of the SMTPU containing IPDI.
研究领域:
材料科学
·
高分子化学
✓ 已验证
产品关联
DOI
高影响因子
Polymers
·
2023
·Vol. 15
·期 12
·2623
·
IF 5
Jiadong Wang,Min Wang,Chenxin Xu,Yang Han,Xuan Qin,Liqun Zhang
The development of damping and tire materials has led to a growing need to customize the dynamic viscoelasticity of polymers. In the case of polyurethane (PU), which possesses a designable molecular structure, the desired dynamic viscoelasticity can be achieved by carefully selecting flexible soft segments and employing chain extenders with diverse chemical structures. This process involves fine-tuning the molecular structure and optimizing the degree of micro-phase separation. It is worth noting that the temperature at which the loss peak occurs increases as the soft segment structure becomes more rigid. By incorporating soft segments with varying degrees of flexibility, the loss peak temperature can be adjusted within a broad range, from −50 °C to 14 °C. Furthermore, when the molecular structure of the chain extender becomes more regular, it enhances interaction between the soft and hard segments, leading to a higher degree of micro-phase separation. This phenomenon is evident from the increased percentage of hydrogen-bonding carbonyl, a lower loss peak temperature, and a higher modulus. By modifying the molecular weight of the chain extender, we can achieve precise control over the loss peak temperature, allowing us to regulate it within the range of −1 °C and 13 °C. To summarize, our research presents a novel approach for tailoring the dynamic viscoelasticity of PU materials and thus offers a new avenue for further exploration in this field.Keywords:micro-phase separation;polyurethane;dynamic viscoelasticity;diols
研究领域:
材料科学
·
高分子化学
·
机械工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2024
·
IF 8.1
Meng-Chao Yu,Xiaojie Xu,Tao Wang,Ying-Nan Feng,Zhi-Ping Zhao
Membrane distillation has long been a potential desalination technology. Recently, spray-assisted non-solvent induced phase inversion (SANIPS) was proposed as a facile and effective method to prepare microporous hydrophobic membranes for membrane distillation. However, the membrane formation process is not fully disclosed. In this paper, SANIPS is employed to fabricate hydrophobic PVDF membranes. The influencing factors on membrane structure and performance are investigated. Membrane structure is greatly affected by the choice of solvent and non-solvent spray. The interactions between different non-solvent sprays (water and ethanol) and solvents (TEP, NMP and DMF) and the effects of operating conditions on membrane formation are explored. Thermodynamic and kinetic analyses of the membrane formation process suggest that the membrane formation process is dominated by the kinetic factors with water being the spray while thermodynamic factors play the major role with ethanol being the spray. A hydrophobic membrane with water contact angle of 135.93 ± 4.38° and LEP of 2.5 ± 0.4 bar was successfully prepared by using ethanol as the non-solvent spray, which demonstrates a stable desalination performance (initial flux of 19.88 ± 1.39 kg·m −2 ·h −1 and salt rejection higher than 99.97 %) in vacuum membrane distillation. This study may provide pertinent insights into the rational control of membrane structure and performance of hydrophobic PVDF membranes.
研究领域:
化学工程
·
材料科学
·
海水淡化技术
✓ 已验证
产品关联
DOI
高影响因子
MACROMOLECULAR CHEMISTRY AND PHYSICS
·
2025
·
IF 2.7
Bo Cai,Zihao Liu,Zhijia Zhang,Songsong Zhang,Qiang Wang,Teng Ma,Lin Wang,Xiaoji Liu,Guojun Wang,Hao Wei,Lei Wang
Inspired by the process of poison transport from in vivo to the skin of poison dart frogs, a novel polyurethane marine antifouling coating PU-xA is prepared, in which the antifouling agent N-(2,3,4-trihydroxy-5-acrylamide methylbenzyl)acrylamide (AMTHBA) would enrich at the surface of the coating due to phase separation. The surface morphology and properties of the composite coating are investigated through the transmittance and haze tester, the atomic force microscope (AFM), and the water contact angle. With the addition of AMTHBA, the water contact angle of the coating gradually decreases from 94.1°± 0.5° to 72.6°± 0.5°, and the surface energy increases from 30.8 to 42.1 J m − 2 . After being immersed in seawater for 28 days, the tensile strength and the elongation at break of PU-25A still kept 3.0 MPa and 136.3%, respectively. The antibacterial performance of the coating increases with the increase of storage time, and the antibacterial rate of PU-25A against Escherichia coli increases from 63.3% to 97.2% after 30 days of storage, and the antibacterial rate against Staphylococcus aureus increases from 59% to 80.1% after 30 days of storage. The outstanding resistance of seawater, antibacterial, and anti-algae adhesion of the PU-25A indicate that PU-25A has potential applications in the field of marine antifouling.
研究领域:
材料科学
·
海洋生物学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）