COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
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2022
·
IF 5.518
Yanan Zhang,Fei Lu,Yang Yu,Long Su,Yanan Gao,Liqiang Zheng,Xinpei Gao
Ionic liquid (IL)/H 2 O mixtures with tunable lower critical solution temperature (LCST) behavior exhibit tantalizing prospect in the field of liquid-liquid phase separation and purification. Herein, different types of amphiphiles were evaluated for the facile regulation of IL ([P 4444 ][DMBS]) based aqueous biphasic systems (ABSs). Interestingly, the addition of zwitterionic 3-(1-dodecyl-3-imidazolio) propanesulfonate (DIPS) remarkably increases the phase separation temperature of IL aqueous solution, while the addition of anionic sodium dodecyl benzene sulfonate (SDBS) and dodecyl-benzenesulphonic acid (DBSA) results in decreasing of the phase separation temperature. The tunable phase separation temperature ranges from 10 to 90 °C, which almost cover the full usable temperature range of ABSs. The regulation mechanism of amphiphile additives on the LCST behavior of IL/H 2 O mixtures was investigated through isothermal titration calorimetry , 1 H NMR spectroscopy and molecular dynamics simulations . Briefly, the addition of zwitterionic DIPS increased LCST through electrostatic shielding effect, while the addition of anionic SDBS and DBSA decreased LCST through ion exchange effect. As a proof of concept, the amphiphile regulated ABSs were demonstrated to selectively separate aliphatic and aromatic amino acids .
研究领域:
化学
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材料科学
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分离技术
·
物理化学
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产品关联
DOI
高影响因子
MACROMOLECULAR CHEMISTRY AND PHYSICS
·
2023
·Vol. 225
·期 5
·2300361
·
IF 2.5
Dan Liu,Hui Liang,Jiang Lu
A novel monomer, N -(2-((3-morpholine-3-isopropyl)thio)ethyl)methacrylamide (MTMA), is synthesized and polymerized by reversible addition-fragmentation chain transfer (RAFT) polymerization to give a thermoresponsive polymer poly[ N -(2-((3-morpholino-3-oxopropyl)thio)ethyl)methacrylamide] (PMTMA). PMTMA exhibits reversible thermoresponsive phase transitions of the lower critical solution temperature (LCST) type in water and the upper critical solution temperature (UCST) type in ethanol and methanol. The degree of polymerization and concentration of PMTMA, and solvent type have a significant influence on the transition temperature. PMTMA shows complicated thermoresponse in water–alcohol mixtures. In water–ethanol mixtures, the phase diagram of PMTMA can be divided into three regions according to ethanol volume percentages, φ : 0 ≤ φ < 15% for an LCST region; 15% ≤ φ < 91.5% for a complete dissolution region; 91.5% ≤ φ ≤ 100% for a UCST region. At high water content, the LCST increases with increasing ethanol content; and at high ethanol content, the UCST decreases with increasing water content. In water–methanol mixtures, PMTMA shows more complex thermoresponse. In the range of 0–50 °C, the phase diagram can be divided into five regions, depending on the methanol volume percentages φ : 0 ≤ φ < 15% for LCST region; 15% ≤ φ < 25% for immiscible region; 25% ≤ φ < 85% for UCST region; 85% ≤ φ < 95% for fully dissolved region; 95% ≤ φ ≤ 100% for another UCST region.
研究领域:
高分子化学
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材料科学
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物理化学
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DOI
高影响因子
MACROMOLECULES
·
2015
·
IF 5.8
Zefeng Song,Ke Wang,Chengqiang Gao,Shuang Wang,Wangqing Zhang
A new multi-stimuli-responsive homopolymer of poly[N-[2-(diethylamino)ethyl]acrylamide] (PDEAEAM), which combines the thermoresponsive and pH/CO2-responsive moieties of the diethylamino and acrylamide groups, was proposed and synthesized by RAFT polymerization. Well-defined PDEAEAM was synthesized by solution RAFT polymerization as indicated by the linear increase in the polymer molecular weight with the monomer conversion and the narrow molecular weight distribution. The appending diethylamino group in the polymer backbone was found to be crucial to determine the thermoresponse of PDEAEAM in water. The parameters including the polymerization degree, the polymer concentration, the deuterated solvent, the terminal attached on the polymer backbone, the additives of salt and urea, and pH and bubbling CO2 affecting the thermoresponse of PDEAEAM in aqueous solution at the lower critical solution temperature (LCST) were investigated. The temperature-variable 1H NMR analysis suggests that the dehydration of PDEAEAM at temperature above LCST is ascribed to the weakened hydrogen bonding between the CONHCH2 and/or (CH2N(CH2CH3)2) moieties with the solvent of water. The proposed multi-stimuli-responsive homopolymer of PDEAEAM has two advantages of (1) the convenient and controllable RAFT synthesis and (2) the pH/CO2 tunable LCST at ∼36 °C being very close to body temperature.
研究领域:
高分子化学
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材料科学
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产品关联
DOI
高影响因子
MACROMOLECULAR CHEMISTRY AND PHYSICS
·
2026
·Vol. 227
·期 10
·e70276
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IF 2.8
Wei Zhang,Qiurui Lin,Yanling Liu,Xinyue Zhao,Xinyu Ma,Xianru He
Hydrogen bonding is one of the key factors determining polymer thermoresponsiveness. For instance, in Upper Critical Solution Temperature (UCST) poly(acrylamide- co -acrylonitrile) (P(AAm- co -AN)) aqueous solution, hydrogen bonding between AAm units is the primary driving force for the UCST transition. If the hydrogen atoms on the amide group are substituted, the absence of hydrogen donors may influence the thermoresponsive behavior and could even induce a shift from Upper Critical Solution Temperature to Lower Critical Solution Temperature (LCST). In this work, poly(N,N-dimethylacrylamide- co -acrylonitrile) (P(DMAA- co -AN)) was synthesized. Because the copolymer contains only hydrogen acceptors, hydrogen bonding cannot form between polymer structural units in aqueous solution. Thus, only polymer–water hydrogen bonding is formed. P(DMAA- co -AN) exhibits typical LCST-type thermoresponsive behavior, which confirms the proposed hypothesis. The copolymers exhibited cloud points in the ambient temperature range of 19°C−68°C by varying the composition ratio of DMAA and AN. P(DMAA- co -AN) exhibits thermoresponsive, salt- and pH-responsive behaviors, which provide potential applications in the fields of biomedicine and petrochemical engineering. In this work, hydrogen bonding interactions were regulated by simply replacing hydrogen atoms on the functional groups, thus inducing changes in the thermoresponsiveness of the copolymer. It offers valuable insights for the design of novel thermoresponsive polymers.
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DOI
高影响因子
POLYMER
·
2015
·
IF 3.562
Shichao Zhang,Kun Chen,Jianyong Yu,Bin Ding
Numerical models that are capable to quantitatively elaborate the formation of novel two-dimensional (2D) nanonets during electrospinning/netting would have broad technological implications for areas ranging from sensing devices and individual protection to industrial filtration and separation; however, creating such models has proved extremely challenging. Here we report novel numerical models for clarifying the origin, evolution, and regulation of the nanonets via combining the ejection modes of Taylor cone apex and the phase separation of charged droplets. Our models propose two critical condition formulas for the generation of jets and droplets, and a LCST phase diagram combined with concentration sweep paths for the nanonets or non-porous films. The resulting model predications exhibit excellent agreement with the experimental results obtained via varying the solution properties and process parameters. The successful model derivation for the nanonets formation may provide new insights into the design and development of 2D multifunctional nanomaterials for various applications.
研究领域:
材料科学
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物理学
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工程学
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产品关联
DOI
高影响因子
Polymer Chemistry
·
2024
·Vol. 15
·期 27
·2780-2789
·
IF 4.1
Ke Wang,Zilong Wang,Meiyu Si,Xiaofang Liu,Guiyan Liu,Yongfei Zeng
Three novel temperature/pH/CO2-triple-responsive homopolymers namely P(Et-N-EO2MA), P(THP-N-EO2MA) and P(Ph-N-EO2MA) were prepared by reversible addition–fragmentation chain transfer (RAFT) polymerization. They have the same backbone structure but different types of end substituents i.e., ethyl, tetrahydropyran, and the benzene ring, respectively. Subsequently, their responsive properties were studied. P(Et-N-EO2MA) has a lower critical solution temperature (LCST)-type cloud point (CP) in aqueous solution and is affected by many factors such as the molecular structure and weight, concentration, additives, pH and CO2. P(THP-N-EO2MA) is soluble in water, but in different buffer solutions, it shows a soluble–LCST–insoluble transition, and its LCST-type CP can also be adjusted by molecular weight and concentration. P(Ph-N-EO2MA) is insoluble in water, but reversible phase transformation can be achieved by adjusting the pH of the solution or injecting CO2, and it also shows different properties in buffer solutions and an upper critical solution temperature (UCST)-type CP in n-butanol. In addition, since P(Ph-N-EO2MA) is amphiphilic, it can be self-assembled in solution, and the release of Nile Red (NR) can be achieved under the stimulation of acid. The different properties of these homopolymers show the effect of substituents on the responsiveness of multistimuli-responsive polymers, which provides ideas for the design of stimuli-responsive polymers, and have good application prospects in the fields of self-assembly and controlled release.
研究领域:
高分子化学
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材料科学
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DOI
高影响因子
JOURNAL OF POLYMER SCIENCE PART A-POLYMER CHEMISTRY
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2015
·Vol. 53
·期 21
·2469-2480
·
IF 3.113
Yong Deng,Xi Wang,Qiulin Yuan,Mengxiang Zhu,Ying Ling,Haoyu Tang
A series of side-chain-functionalized α-helical polypeptides, i.e., poly(γ-4-(3-chloropropoxycarbonyl)benzyl- L -glutamate) (6) have been prepared from n-butylamine initiated ring-opening polymerization (ROP) of γ-4-(3-chloropropoxycarbonyl)benzyl- L -glutamic acid-based N -carboxyanhydride. Polypeptides bearing oligo-ethylene-glycol (OEG) groups or 1-butylimidazolium salts were prepared from 6 via copper-mediated [2+3] alkyne-azide 1,3-dipolar cycloaddition or nuleophilic substitution, respectively. CD and FTIR analysis revealed that the polymers adopt α-helical conformations both in solution and the solid state. Polymers bearing OEG (m = 3) side-chains showed reversible LCST-type phase transition behaviors in water while polymers bearing 1-butylimidazolium and I − counter-anions exhibited reversible UCST-type transitions in water. Variable-temperature UV-vis analysis revealed that the phase transition temperatures ( T pt s) were dependent on the main-chain length and polymeric concentration. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015 , 53 , 2469–2480
研究领域:
高分子化学
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生物材料
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产品关联
DOI
高影响因子
Science China-Chemistry
·
2016
·Vol. 59
·期 5
·587-593
·
IF 2.429
Pei Yuanchao,Cao Yuan,Huang Yanjie,Song Xinxin,Wang Huiyong,Zhao Yuling,Wang Jianji
In this work, 16 kinds of [FeCl 4 ] - -based magnetic ionic liquids (ILs) with different cation structures have been designed and synthesized, and their structures are characterized by IR and Raman spectroscopy. Then the lower critical solution temperature (LCST)-type phase behavior of these magnetic ILs in water is investigated as a function of concentration. It is shown that cation structure, alkyl chain length and molar ratio of FeCl 3 /chloride IL have a significant influence on the LCST of the mixtures. The phase separation temperature can be tuned efficiently by these factors. Meanwhile, the LCST-type phase separation process is also investigated by dynamic light scattering. The results support the mechanism that the hydrogen bonds of the [FeCl 4 ] - anion with water have been gradually disrupted to form ILs aggregates with increasing temperature. In addition, the stability of the ILs in water is also examined in some details. These LCST-type phase separation systems may have potential applications in extraction and separation techniques at room temperature.
研究领域:
化学
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材料科学
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产品关联
DOI
高影响因子
CARBOHYDRATE POLYMERS
·
2018
·
IF 5.158
Kaiqiang Zhang,Yulin Shi,Liang Wu,Long Chen,Tingting Wei,Xin Jia,Zhang Chen,Manqiu Li,Yisheng Xu,Yu Wang,Yanfeng Gao,Xuhong Guo
A thermo and pH dual-responsive starch (TPDS) was successfully synthesized by etherification, in which butyl glycidyl ether (BGE) was used as the hydrophobic reagent followed by addition of 2-chloro-4, 6-diglycino-[1,3,5]-triazine (CDT) groups. The obtained materials were characterized by Fourier transform–infrared spectroscopy (FTIR), 1 H nuclear magnetic resonance ( 1 H NMR) and elemental analysis to confirm the structure and the average substitution degree of BGE and CDT on starch molecule. It was observed that the lower critical solution temperature (LCST) of the TPDS could be modulated from 31 °C to 47 °C by increasing pH of the solution. The effects of pH and the concentration of such materials on the energy-saving performance of TPDS which could be potentially used as smart windows were investigated by UV-vis-NIR spectrophotometry. The solar modulating ability (△T sol ) and the luminous transmittance (△T lum ) of the sample were 40.1% and 47.1% when 10 g/L TPDS was chosen at pH 3. The results indicate that TPDS exhibits excellent optical performance with a controllable LCST, which shows great potential for the application as a smart window.
研究领域:
材料科学
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化学工程
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产品关联
DOI
PubMed
高影响因子
ChemistrySelect
·
2025
·Vol. 10
·期 37
·e02789
·
IF 2
Li Zhong,Yuxin Duan,Meiying Wang,Xiao Xu,Minghuan Qian,Xu Jia
The polymers of N , N -diethylacrylamide (DEA) exhibit temperature-dependent sensitivity attributable to the presence of both hydrophilic and hydrophobic groups. However, their lower critical solution temperature (LCST) is only 25 °C, a limitation that restricts their practical applications. Previous studies have shown that the incorporation of cationic monomers for copolymerization can enhance the LCST of polymers. In this study, dimethyldiallylammonium chloride (DMDAAC) and DEA were selected for copolymerization to obtain a series of thermosensitive water-soluble polymers, poly(DMDAAC- co -DEA). Structure and properties were characterized using FT-IR, 1 H NMR, TG-DSC, and surface tension test. Combined with the critical phase transition mechanism, it was determined that the hydrophilicity of the polymer underwent a gradual increase in proportion with the increase of DMDAAC blocks in polymers, and the LCST exhibited an increase of up to 36.8 °C. The relationship between polymer structure and demulsification performance was also explored, as represented by the application of O/W emulsion. The experimental findings demonstrated that all poly(DMDAAC- co -DEA) products exhibited effective demulsification performance. The demulsification rate of the polymers with 30%, 50%, and 70% of DMDAAC could reach 97.03%, 98.20%, and 98.40% respectively, which shows great potential for the petroleum demulsification application. Graphical Water-soluble polymer Poly(DMDAAC- co -DEA) are synthesized using a three-step heating method. A comprehensive investigation is conducted into the relationship between its LCST and copolymerization ratio, resulting in the elucidation of the underlying mechanism. Furthermore, the demulsifying properties of the copolymer are investigated.
研究领域:
高分子化学
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石油化学
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胶体与界面科学
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功能材料
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分离技术
✓ 已验证
产品关联
DOI
高影响因子
Polymers
·
2015
·Vol. 7
·期 5
·909-920
·
IF 3.681
Tao Chen,Qisheng Fang,Qi Zhong,Yangyi Chen,Jiping Wang
We tuned the lower critical solution temperature (LCST) of amphiphilic poly(N-isopropylacrylamide) (PNIPAAm) via copolymerization with a hydrophilic comonomer ofN-hydroxymethyl acrylamide (NHMAAm). A series of copolymers P(NIPAAm-co-NHMAAm) were synthesized by atom transfer radical polymerization (ATRP) using CuBr/(N,N,N',N',N''-Pentamethyldiethylenetriamine) (PMDETA) as a catalyst system and 2-bromo ethyl isobutyrate (EBiB) as an initiator. The copolymers were well characterized by Fourier transform infrared spectroscopy (FT-IR),1H Nuclear magnetic resonance (NMR), and Thermogravimetric analysis (TGA). The copolymers followed a simple rule in their thermosensitive behaviors and have a linear increase in the LCST as a function of NHMAAm mol%. The thermosensitive properties of the copolymer films were investigated and demonstrated hydrophilic-hydrophobic transitions. Finally, the copolymer was grafted onto cotton fabrics using citric acid (CA) as a crosslinking agent and sodium hypophosphite (SHP) as a catalyst following a two dipping, two padding process. The large number of hydroxyl groups in the copolymer makes grafting convenient and firm. The grafted cotton fabrics show obvious thermosensitive behaviors. The results demonstrate that the cotton fabrics become more hydrophobic when the temperature is higher than the LCST. This study presents a valuable route towards temperature-responsive smart textiles and their potential applications.Keywords:synthesis;thermosensitive behavior;copolymer;tunable LCST;smart textile
研究领域:
材料科学
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纺织工程
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产品关联
DOI
高影响因子
POLYMER JOURNAL
·
2023
·Vol. 55
·期 12
·1295-1305
·
IF 2.8
Zhou Qian,Liu Bing,Jia Zhaolei,Gao Xuejiao,Ba Xinwu,Zhang Yuangong,Bai Libin
The aqueous solution of hyperbranched poly(bis-acrylamide)s (HPEAMs) prepared by reversible addition-fragmentation chain transfer (RAFT) polymerization has a lower critical solution temperature (LCST), which can also respond to HCO 3 - . However, the phase change mechanism of HPEAMs has not yet been proven. In this paper, N -(2-propionamidoethyl)acrylamide was designed as a monomer and chain transfer agent (CTA), and the corresponding linear polymers, hyperbranched polymers and hyperbranched copolymers were further prepared. Fourier transform infrared spectroscopy, 1 H nuclear magnetic resonance, ultraviolet‒visible spectroscopy, dynamic light scattering and zeta potential were employed to characterize the structure and phase transition behavior. The results confirmed that the bis-acrylamide unit is hydrophilic and the CTA unit is hydrophobic. The hydrophilic-hydrophobic balance system constructed by the unit of bis-acrylamide and CTA endowed the hyperbranched polybisacrylamide with temperature-responsive behavior, and the carboxyl group in the CTA structural unit is the responsive group that makes it possible to tune the LCST in the presence of HCO 3 - .
研究领域:
高分子化学
·
材料科学
✓ 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）