Science China-Chemistry
·
2016
·Vol. 59
·期 5
·587-593
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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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DOI
高影响因子
Frontiers of Materials Science
·
2017
·Vol. 11
·期 3
·223-232
·
IF 1.471
Wei Lulu,Lu Beibei,Li Lei,Wu Jianning,Liu Zhiyong,Guo Xuhong
A novel β-cyclodextrin-poly(2-(2-methoxyethoxy)ethyl methacrylate)- co -poly(ethylene glycol) methacrylate (abbreviated as: β-CD-(P(MEO 2 MA- co -PEGMA)) 21 ) was prepared by using the one-step strategy, and then the star-shaped copolymers were used in the atom transfer radical polymerization (ATRP). The structure of star-shaped β-CD-(P(MEO 2 MA- co -PEGMA)) 21 copolymers were studied by FTIR, 1 H NMR and gel permeation chromatography (GPC). The star-shaped copolymers could self-assembled into micelles in aqueous solution owing to the outer amphiphilic β-CD as a core and the hydrophilic P(MEO 2 MA- co -PEGMA) segments as a shell. These thermo-responsive starshaped copolymers micelles exhibited lower critical solution temperature (LCST) in water, which could be finely tuned by changing the feed ratio of MEO 2 MA to PEGMA. The LCST of star-shaped β-CD-(P(MEO 2 MA- co -PEGMA)) 21 copolymer micelles were increased from 35°C to 58°C with the increasing content of PEGMA. The results were investigated by DLS and TEM. When the temperature was higher than corresponding LCSTs, the micelles started to associate and form spherical nanoparticles. Therefore, β-CD-(P(MEO 2 MA- co -PEGMA)) 21 star-shaped copolymer micelles could be potentially applied in nano-carrier, nano-reactor, smart materials and biomedical fields.
研究领域:
材料科学
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高分子化学
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纳米技术
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产品关联
DOI
高影响因子
JOURNAL OF POLYMER RESEARCH
·
2020
·Vol. 27
·期 8
·1-11
·
IF 2.426
Fu Congcong,Ding Lan,Yin Jialin,Tian Shasha,Ma Lan,Zhang Qi,Qin Fei,Cao Lili,Deng Kuilin
In this investigation, we described a facile preparation of temperature/photo dual sensitive polymers (PGABs) by Ugi four-component polymerization (Ugi-4CP) at room temperature in “one-pot” method using glutaraldehyde, 4 -amido-azobenzene, t -butyl isocyanide and carboxyl-end-capped polyethylene glycols (S-PEG) as monomers. PGABs were found to be reversibly sensitive to the temperature in salt solution, and their lower critical solution temperatures (LCST) can be tuned to the range of 17.2–68.4 °C by changing the structure of PGABs, sort and concentration of salt. The configuration transition of PGABs between cis -form and trans -form was reversibly induced by the alternating radiation at 365 and 254 nm. The rate and conversion of isomerization showed a remarkable dependence on the chemical structure of PGAB. By the photosensitivity, the LCST of PGAB-800 is further regulated in 1.0 °C change because of the hydrophilicity difference of cis - trans -azobenzene moiety. Through the combination of the thermosensitivity and photosensitivity, the particles of PGABs with nano/μm dimension were successfully controlled by the light radiation and temperature change.
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
POLYMER INTERNATIONAL
·
2021
·Vol. 70
·期 9
·1376-1385
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IF 2.99
Yanli Li,YeFang Yang,Xinqi Pei,Yu Li,Yuhui Yuan,Xiaoling Huang
Cucurbit[6]uril-derivatized vinyl monomer (cucurbit[6]uril methacrylate) was synthesized. Acrylic acid (AA) was used as the comonomer for copolymerization with the cucurbit[6]uril-derivatized monomer. A series of copolymers of poly(acrylic acid- co -cucurbit[6]uril methacrylate) (PAA- co -CB[6]MA) were synthesized by free radical polymerization. The cucurbit[6]uril-derivatized monomer and PAA- co -CB[6]MA copolymers were characterized by 1 H NMR spectra, high-resolution mass spectroscopy and gel permeation chromatography. The solution behavior was examined using UV–visible spectroscopy and dynamic light scattering. The PAA- co -CB[6]MA showed an upper critical solution temperature (UCST) in water. The UCST-type thermoresponsive behavior of these CB[6]-derivatized copolymers was highly dependent on the composition of the copolymer. For the same type of copolymer, changes in its composition gave rise to different UCSTs. Additionally, the PAA- co -CB[6]MA copolymers were successful in trapping azocarmine B. The stimuli-responsive release of encapsulated azocarmine B was achieved by a combination of temperature and pH value stimuli. According to the results, the novel PAA- co -CB[6]MA copolymers can be used as carriers. © 2021 Society of Industrial Chemistry.
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
INTERNATIONAL JOURNAL OF POLYMER ANALYSIS AND CHARACTERIZATION
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2024
·
IF 1.7
Ha Ngoc Giang,Dung Thi Phuong Truong,Xuan Kim Hoang,Tuan Nguyen Anh Huynh
Hydroxypropyl cellulose (HPC) and its rather low lower-critical-solution-temperature (LCST) were the main research targets in many recent publications. In this study, a simple and affordable approach to measure LCST using a Brookfield viscometer was presented. The setup using a popular hot plate and a silicone oil bath could well detect the HPC solution’s LCST values. The result was in good agreement with the particle size change obtained using the dynamic light scattering technique. The effect of polyacrylic acid (PAA) and other cellulose derivatives including hydroxypropyl methylcellulose (HPMC), hydroxyethyl cellulose (HEC), or sodium carboxymethyl cellulose (CMC) on HPC’s LCST was investigated. The mixture of HPC with PAA, HPMC, and CMC showed the lowest LCST. However, the effect of NaCl seemed to be stronger when the LCST value of only 28.5 °C was obtained with 1 wt% of HPC and 5 wt% of NaCl. Fourier-transformed infrared spectroscopy results also showed a stronger interaction of HPC/NaCl compared to the mixture with PAA of HPMC. The differential scanning calorimetry only detected the signal change correlated with LCST in the cooling cycle. The glass window fabricated with the current thermochromic solution was able to block and transmit visible light well at low and elevated temperatures, respectively.
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
高影响因子
Polymer Chemistry
·
2014
·Vol. 5
·期 15
·4561-4568
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IF 5.368
Deyang Yu,Chunhui Luo,Wenxin Fu,Zhibo Li
Five (meth)acrylamide derivatives containing alanine ester/amide residues were synthesized and then polymerized using RAFT polymerization. After polymerization and further treatment of the obtained polymers with excess radical initiators, we obtained a series of homopolymers with well-defined molecular weights and end groups. Depending on the structure of side-chain terminal groups, these alanine-containing homopolymers displayed thermal-responsive behaviors in water. Samples containing a methyl ester group, i.e., poly(MA-L-Ala-OMe) and poly(Ac-L-Ala-OMe), showed low critical solution temperature (LCST) behaviors. Replacing methyl ester with ethyl or isopropyl ester groups caused loss of thermal-responsive properties. However, replacing the isopropyl ester with isopropyl amide groups can regain thermal-responsive polymers such as poly(MA-L-Ala-iPA). We further studied the LCST behaviors of these three homopolymers with respect to the degree of polymerization (DP), concentration, salt concentration, and chirality of amino acids. It was found that the cloud point (CP) decreased with increasing polymer concentration, DP and salt concentration. The CPs of the polymers prepared from a pair of enantiomers showed no distinct difference, while the random copolymer of the two enantiomers displayed higher CP than optically pure homopolymers.
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
JOURNAL OF POLYMER SCIENCE PART A-POLYMER CHEMISTRY
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2012
·Vol. 51
·期 6
·1405-1416
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IF 3.919
Cheng-Guang Mu,Xiao-Dong Fan,Wei Tian,Yang Bai,Zhen Yang,Hao Yao,Heng Chen
We report on the synthesis of an H-shaped polymer bonding β-cyclodextrin (β-CD) at branch points and influences of attached β-CD on physical properties. First, a poly(ethylene glycol)(PEG)-based functional macroinitiator bearing two azidos and four chlorines at chain-ends (PEG-2N 3 (-4Cl)) was prepared via terminal modification reactions. Then, PEG-2N 3 (-4Cl) was applied to initiate the atom transfer radical polymerization of N-isopropylacrylamide, leading to the synthesis of an H-shaped block polymer with PEG as the central chain and poly( N -isopropylacrylamide) (PNIPAM) as side-arms (PEG-2N 3 (-4PNIPAM)). Azido groups were at the branch points of the polymer. Finally, the click reaction between PEG-2N 3 (-4PNIPAM) and alkynyl monosubstituted β-cyclodextrin (β-CD) afforded another H-shaped polymer with two β-CDs bonding at the polymer branch points (PEG-2CD(-4PNIPAM)). The glass transition temperature ( T g ) and lower critical solution temperature (LCST) of the H-shaped polymer increased after the attachment of β-CD. The self-assembly and thermal responsive behaviors, as well as the encapsulation behaviors of PEG-2CD(-4PNIPAM) were also altered. When temperature was below the LCSTs, PEG-2N 3 (-2PNIPAM) dissolved in water molecularly, whereas PEG-2CD(-4PNIPAM) could self-assemble into nano-sized micelles. After the LCST transitions, PEG-2N 3 (-4PNIPAM) aggregated into micron-sized unstable particles, whereas PEG-2CD(-4PNIPAM) transformed into PNIPAM-cored nanomicelles. Besides, PEG-2CD(-4PNIPAM) can encapsulate doxorubicin below its LCST due to the formation of micelles. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013
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
·
2019
·Vol. 220
·期 13
·1900129
·
IF 2.622
Alberto García-Peñas,Chandra Sekhar Biswas,Weijun Liang,Yu Wang,Florian J. Stadler
Poly( N -Isopropylacrylamide) has a broad potential range of biomedical applications owing to its lower critical solution temperature (LCST). This work tries to elucidate the real influence of several parameters on LCST by comparing homopolymers prepared by free radical polymerization and reversible addition–fragmentation chain transfer (RAFT) polymerization using conventional calorimetry, turbidimetry, and rheology as well as how three different methods can be used to detect the LCST. These methods are compared to gain a deeper understanding of the underlying processes and how they are related to molar mass and synthesis methods. The diverse interactions associated with the LCST transitions are more sensitive depending on the ratio defined between polymerization degrees and end-group effects. Thus, the selection of a high sensitive method for LCST detection depends on the molecular features defined from the homopolymer. In addition, this work shows also the importance of the RAFT agent selected for the synthesis, which can modify substantially the LCST in comparison with other methods reported where the use of chemicals, complex processes, and costs considerably increase.
研究领域:
生物医学工程
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高分子化学
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产品关联
DOI
高影响因子
REACTIVE & FUNCTIONAL POLYMERS
·
2023
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IF 5.1
Lesly Dasilva Wandji Djouonkep,Binqiang Xie,Huaizhi Tao,Lvyan Zhuo,Alain Pierre Tchameni,Lin Zhao
This study investigates the structure and comparison of solution properties of a series of acrylamide-based polymers capped by different thermo-sensitive side chains such as N-vinyl caprolactam (NVCL), N , N -dimethylacrylamide (DEAM) and N-isopropylacrylamide (NIPAM) synthesized via continuous initiation free-radical polymerization. Techniques such as Fourier-transform infrared spectroscopy (FTIR) and proton nuclear magnetic resonance ( 1 H NMR) afforded the chemical structure , X-ray diffraction (XRD) exhibit the tacticity and environmental scanning electron microscopy (ESEM) displayed the morphology. Turbidimetry , dynamic light scattering (DLS), and DSC techniques examined the responsiveness and hydrodynamic radii of the colloidal particles at their lower critical solution temperature (LCST). The thickening profiles were investigated via rheometric analysis and the relationship between viscoelastic properties and hydrodynamic radii synergistically explained the anomalous viscosity build-up among the different side chains. The polymers exhibited excellent thickening abilities at high temperatures (>70 °C) with relatively rough surface mixed intercalations attributed to the thermo-responsive moieties grafted on acrylamide methylpropane sulfonic acid (AMPS) as thermal resistance backbone. PAMPS/NVCL displayed particularly excellent responses owing to its partial conjugation effect, compared to PAMPS/DEAM and PAMPS/NIPAM in solution at 150 °C. The polymers also displayed strong anti-salt responses, with a drop in viscosity initially observed but quickly subdued due to hydrophobic side chain association, electrostatic shield, and double-layer compression of the hydrated shells. These polymer side chains grafted on acrylamide backbones promote excellent self-assembly properties at varying grafting ratios and are interesting as self-adaptive rheology modifiers and fluid immobilizers for enhanced oil and gas recovery in deep reservoirs.
研究领域:
材料科学
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高分子化学
✓ 已验证
产品关联
DOI
高影响因子
POLYMERS FOR ADVANCED TECHNOLOGIES
·
2016
·Vol. 27
·期 10
·1376-1382
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IF 1.823
Naipu He,Yue Wang,Zhenwu Lu
The temperature-responsive poly (N, N-diethylacrylamide) (pDEAAm) with narrower molecular weight distribution was prepared by the atom transfer radical polymerization and characterized by 1 HNMR and gel permeation chromatography. The temperature-responsive “tadpole-shaped” BSA–pDEAAm hybrids were fabricated via a free Cys-34 residue of bovine serum albumin (BSA) site specifically binding to the end group disulfide bonds of pDEAAm and characterized by native-polyacrylamide gel electrophoresis (Native-PAGE) and matrix-assisted laser desorption/ionization time of flight mass spectrometry. Their temperature-responsive behaviors were measured by ultraviolet-visible spectra (UV-Vis). The lower critical solution temperature (LCST) of the pDEAAm was identified as 28°C, and the LCST of BSA–pDEAAm hybrids was identified as 31°C. The morphologies of BSA–pDEAAm hybrids self-assembled in the aqueous solutions with two different temperatures at 25 °C and 40°C were investigated by transmission electron microscopy. Below the LCST of BSA–pDEAAm hybrids, the separate spherical nanoparticles were observed. In contrast, bundles and clusters were observed above the LCST of BSA–pDEAAm hybrids. The results suggested that the self-assembly morphology of BSA–pDEAAm hybrids depended upon the pDEAAm block in BSA–pDEAAm hybrids, and the morphology transitions were effected by the LCST of BSA–pDEAAm hybrids. It would be expected to be used in biomedicine and materials science. Copyright © 2016 John Wiley & Sons, Ltd.
研究领域:
高分子化学
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材料科学
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生物医学工程
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DOI
高影响因子
BIOMACROMOLECULES
·
2019
·
IF 5.667
Jia Tian,Baoxuan Huang,Haiquan Li,Hongliang Cao,Weian Zhang
Premature and incomplete drug release is the typical bottleneck of drug release in traditional chemotherapy. Synergistic therapies are highly desirable in medicine and biology because they can compensate for the drawbacks of single therapy and significantly enhance the therapeutic efficacy. Herein, a novel near infrared (NIR)-activated polymeric nanoplatform with upper critical solution temperature (UCST) was constructed for image-guided synergistic photothermal therapy (PTT) and chemotherapy. UCST-responsive amphiphilic block copolymers were synthesized by reversible addition–fragmentation chain-transfer (RAFT) polymerization and then co-assembled with IR780 and cabazitaxel (Cab) to form spherical nanoparticles (NPs). IR780/Cab dual-loaded UCST polymeric NPs can produce local heating upon NIR laser irradiation and further lead to the dissociation of cargo-loaded NPs and controlled release of Cab. IR780 plays the role of both a heating generator and an activator for “on-demand” drug release. The investigation of in vivo fluorescence and photothermal imaging clearly demonstrated tumor targeting. Notably, both in vitro and in vivo studies illustrated that the synergistic PTT and chemotherapy presented better anticancer efficacy than that of PTT and chemotherapy simplely combined. Thus, the well-defined polymeric nanoplatform opens a versatile and effective path to develop image-guided synergistic therapies for tumor treatment.
研究领域:
生物医学工程
·
肿瘤学
·
纳米医学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Pigment & Resin Technology
·
2021
·Vol. 51
·期 5
·499-507
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IF 1.263
Hongyi Tu,Donglei Liu,Zhenbin Chen,Chunli Liu
PurposeUsing a reversible addition fragmentation chain transfer reaction, a series of resins were prepared by using N, N-diethyl acrylamide (DEA), poly (ß-hydroxyethyl methacrylate) (PHEMA) as hydrophilic blocks and poly (glycidyl methacrylate) (PGMA) as hydrophobic blocks (and as a target for immobilizing penicillin G acylase [PGA]) and the low critical solution temperature (LCST) of which could be adjusted by changing the segment length of blocks.Design/methodology/approachTo make the catalytic conversion temperature of immobilized PGA fallen into the temperature range of the sol state of thermosensitive block resin, a type of thermosensitive block resin, i.e. PDEA-b-PHEMA-b-PGMA (DHGs) was synthesized to immobilize PGA, and the effect of segment order of block resin was investigated on the performance of PGA.FindingsCarrier prepared with monomers molar ratio of n(DEA) : n(HEMA): n(GMA) = 100: 49: 36 presented loading capacity (L) and enzyme activity recovery ratio (Ar) of 110 mg/g and 90%, respectively, and a block resin with LCST value of 33 °C was essential for keeping higher Ar of PGA.Originality/valuePGA has become an important biocatalyst in modern chemistry industry. However, disadvantages include difficulty in separation, poor repeatability and high cost, which limits the scope of PGA applications. The effective method is to immobilize the enzyme to the carrier, which could overcome the disadvantage of free enzyme.
研究领域:
生物化学
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材料科学
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酶工程
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）