POLYMER
·
2018
·
IF 3.483
Ganwei Zhang,Jianbin Lei,Longbo Wu,Chenchen Guo,Jialong Fang,Renbi Bai,Ian Wyman
A series of poly (imidazoled glycidyl methacrylate- co -diethylene glycol methyl ether methacrylate) copolymers (denoted as P (iGMA- co -MEO 2 MA)) with different monomer compositions were synthesized and characterized. These copolymers exhibit lower critical solution temperature (LCST) behaviors as the mole ratio of iGMA to MEO 2 MA in the copolymers range from 0/100 to 1/1, and upper critical solution temperature (UCST) behaviors when this mole ratio ranges from 4/1 to 10/1. The thermoresponsive behaviors of these copolymers were also investigated in water at different pH values. The LCST of the copolymer increased with the iGMA content in the copolymer at pH 6.5, and changed little at pH 7.0, while it decreased with the iGMA content in the copolymer at pH 7.5. Meanwhile, the UCST of the copolymer increased with the iGMA content in the copolymer at pH 6.5 and 7.0. In addition, the thermoresponsive properties of P (iGMA- co -MEO 2 MA) were influenced by the presence of salt and by the copolymer concentration. This paper offers a facile approach toward thermoresponsive materials with tunable LCST and UCST behaviors.
研究领域:
高分子化学
·
材料科学
✓ 已验证
DOI
高影响因子
JOURNAL OF POLYMER RESEARCH
·
2017
·Vol. 25
·期 1
·1-12
·
IF 1.615
Li Yuesheng,Qin Jiangtao,Bao Huaxi,Han Yan,Zeng Xianglin,Zheng Hua,Huang Yaqiong,Xia Xiangxiang,Dong Zhibing,Hu Renhuo,Liu Yi
As a temperature-sensitive-discoloration hydrogel based on NIPAAm/HHPC was fabricated via two steps of electron beam radiation. Small nanomaterial such as GO and Fe 2 O 3 were also added severally into the system of hydrogel as chromogenic agent. Different colors can be displayed in nanocomposite hydrogel system at the low, medium and high temperature respectively. The LCST of hydrogel system can be also adjusted precisely by the changes of irradiation dose of the prepolymer and composition ratio. Experimental results showed that the hydrogel can be changed quickly itself color in its near LCST. The microstructure and composition of nanocomposite hydrogel were characterized further by NMR, FTIR, TG, DSC, XRD, FE-SEM and XPS so as to reveal the mechanism of temperature-sensitive- discoloration. The novel NIPAAm/HHPC-based nanocomposite hydrogel is suitable especially to indicate different fever temperatures for fever patients and can be expected to as a new type of temperature-sensitive sensor and replace the traditional clinical thermometer.
( A ) SEM images of different hydrogels (previous row). ( B ) The reversible temperature-sensitive-discoloration process of different hydrogels ( bottom left ). ( C ) DSC thermograms of different hydrogels ( bottom right ).
研究领域:
材料科学
·
生物医学工程
✓ 已验证
DOI
高影响因子
JOURNAL OF POLYMER RESEARCH
·
2017
·Vol. 24
·期 4
·1-6
·
IF 1.615
Yu Yueqin,Sun Xuejiao,Zhang Ruling,Yuan Shichao,Lu Qingliang,Wu Zongmei
Octadecyl acrylate (ODA) as hydrophobic monomer and N-isopropylacryamide (NIPAAm) as hydrophilic monomer were chosen to synthetize the thermo-sensitive block copolymers PODA x -PNIPAAm y -PODA x (BAB-type) via reversible-addition-fragmentation chain transfer (RAFT) polymerization, the block copolymers could self-assemble to flower-like micelles in aqueous solution with hydrophobic PODA as the inner core and stabilized by hydrophilic PNIPAAm as the outer shell. The characterizations of the micelles such as surfactivity, thermo-sensitivity, micelle hydrodynamic radius ( R
h
) and polydispersity index ( PdI ) were demonstrated by surface tension technique, UV-Vis, and dynamic light scattering (DLS) measurements, respectively. The longer the hydrophilic chain was, the higher the critical micellization concentration (CMC) would be, and the higher content of the PODA was, the lower the lower critical solution temperature (LCST) would be. The average R
h
remained at about 100 nm below LCST, but decreased sharply to about 42 nm and kept constant when reaching and above LCST, which meant the non-aggregation of BAB type block copolymers. The micelle was homogeneous with the small PdI within the range of research. B 0.5m A 24m B 0.5m had the largest capacity to encapsulate lipophilic Sudan Red IV model drugs and the drug loading efficiency was 9.76%.
研究领域:
高分子化学
·
纳米药物载体
·
药剂学
·
材料科学
·
生物医用材料
✓ 已验证
DOI
高影响因子
IRANIAN POLYMER JOURNAL
·
2025
·
IF 2.8
Dai Yunling,Ma Xinyu,Du Pan,Lin Qiurui,Zhang Wei,Yang Yining,He Xianru
Polymers with lower critical solution temperature (LCST) had broad application prospects in biomedicine and drug delivery. The copolymer poly(N-vinylpyrrolidone-co-diacetone acrylamide) (P(NVP-co-DAAM)) was prepared by reversible addition-fragmentation chain transfer (RAFT) polymerization of N-vinylpyrrolidone (NVP) and diacetone acrylamide (DAAM). Ultraviolet transmittance was utilized to investigate its solution behavior. The results showed that by adjusting molar ratio of two monomers, the lower critical solution temperature (LCST) of the copolymer could be modulated for 12.0–59.9 °C. Variable-temperature Fourier transform infrared spectroscopy examined the interactions between the copolymer and water molecules. The results indicated that the hydroxyl absorption peak of the solvent water molecules exhibited blue-shift with rising temperature, indicating weakening interactions between copolymer and water molecules. Two-dimensional infrared correlation spectroscopy results showed that interaction between water molecular and DAAM structural unit weakened prior to that between water molecular and NVP structural unit due to rising temperature. The concentration dependence of the increasing specific viscosity indicated that the aggregation concentration (Cg) of the polymer solution decreased with increasing temperature.Dynamic light scattering experiments showed that the hydrodynamic size increases with increasing temperature above the LCST. The results comprehensively showed that the P(NVP- co -DAAM) copolymer exhibits a sensitive temperature response, and the P(NVP- co -DAAM) structure has good biocompatibility, indicating its significant potential for application in biomedicine and related fields. Graphical
研究领域:
高分子科学
·
材料科学
·
生物医学工程
·
药物输送
·
物理化学
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2018
·
IF 3.909
Lin Shao,Yang Cao,Zhanying Li,Wenbin Hu,Shize Li,Lingbin Lu
Alginate was grafted with NIPAM and NHMAM successfully, and a new responsive copolymer, alginate-g-P(NIPAM-co-NHMAM), was obtained. A novel dual responsive polysaccharide-based aerogel with thermo/pH sensitive properties was designed from the copolymer as drug controlled release system. The chemical structure of the copolymer was characterized by FT-IR and 1 H NMR. Lower critical solution temperature (LCST) of the copolymer covered a wide temperature range from 27.6 °C to 42.2 °C, which could be adjusted with changing the ratio between NIPAM and NHMAM. The dual responsive aerogel had a three-dimensional network structure. As a drug controlled release system, the aerogel was high responsive to both temperature and pH with drug loading efficiency up to 13.24%. Above LCST, the aerogel had a faster drug release, and drug was completely released in neutral environment, while the drug release was obstructed in acid environment. Furthermore, the drug release mechanism of the aerogel was illuminated. These results indicated that the dual responsive aerogel was a promising candidate for drug carriers.
研究领域:
材料科学
·
药学
·
高分子化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Membranes
·
2021
·Vol. 11
·期 11
·803
·
IF 4.106
Qianqian Xu,Yuchao Chen,Tonghu Xiao,Xing Yang
The use of poly(vinylidene fluoride) (PVDF) microfiltration (MF) membranes to purify oily water has received much attention. However, it is challenging to obtain high-performance PVDF microfiltration membranes due to severe surface fouling and rapid decline of permeability. This study explored a new approach to fabricate high-performance PVDF/silica (SiO2) composite membrane via the use of a polymer solution featuring lower critical solution temperature (LCST) characteristics and the non-solvent thermally induced phase separation method (NTIPS). Coupling with morphological observations, the membrane formation kinetics were analyzed in depth to understand the synergistic effect between the LCST solution properties and fabrication conditions in NTIPS. Utilizing such a synergistic effect, the transition from finger-like macrovoid pores to bi-continuous highly connected pores could be flexibly tuned by increasing the PVDF concentration and the weight ratio of SiO2/PVDF in the dope solution and by raising the coagulation temperature to above the LCST of the solution. The filtration experiments with surfactant-stabilized oil-water emulsion showed that the permeation flux of the PVDF/SiO2composite membranes was higher than 318 L·m−2·h−1·bar−1and the rejection above 99.2%. It was also shown that the PVDF/SiO2composite membranes, especially those fabricated above the LCST, demonstrated better hydrophilicity, which resulted in significant enhancement in the anti-fouling properties for oil/water emulsion separation. Compared to the benchmark pure PVDF membrane in oily water purification, the optimal composite membrane T70 was demonstrated via the 3-cycle filtration experiments with a significantly improved flux recovery ratio (Frr) and minimal reduced irreversible fouling (Rir). Overall, with the developed method in this work, facile procedure to tune the membrane morphology and pore structure was demonstrated, resulting in high performance composite membranes suitable for oil/water emulsion separation.Keywords:PVDF/SiO2composite membrane;lower critical solution temperature (LCST);nonsolvent thermally induced phase separation (NTIPS);structural control;oil-in-water emulsion
研究领域:
材料科学
·
环境工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Polymer Chemistry
·
2014
·Vol. 5
·期 19
·5578-5590
·
IF 5.368
Wenlong Li,Peiyi Wu
Dynamic thermal phase transition behavior of a well-defined thermoresponsive ionic liquid (IL), [P4,4,4,4][SS], and its polymer, poly(ionic liquid) (PIL), P[P4,4,4,4][SS], synthesized by modified free radical polymerization was investigated by means of DSC, turbidity, temperature-variable 1H NMR, FT-IR spectroscopy measurements, in combination with perturbation correlation moving window (PCMW) and two-dimensional correlation (2Dcos) analysis. Obvious distinction was observed between the LCST of monomer and polymer solutions indicating their largely different dynamic transition process. Further studies revealed that the aggregation of [P4,4,4,4][SS] is mainly driven by the synergetic variations of cations and anions while the separation process of the P[P4,4,4,4][SS] solution is found to be dominated by conformation changes of anions. Finally, 2Dcos was employed to elucidate the sequence order of chemical group motion during heating. It is concluded that synergetic variations of cations and anions in the [P4,4,4,4][SS] solution resulted in the randomly aggregated structure of globules during separation. In contrast, in the P[P4,4,4,4][SS] solution, anions of repeated units tend to be wrapped into the aggregated globules while cations would distribute at the periphery of globules after transition. Additionally, several unusual phenomena were also interpreted, such as the different varying tendency in LCST of monomer and polymer solutions with increasing concentration, their distinction in the final transmittance and their rather different LCST at the same concentration.
研究领域:
高分子化学
·
物理化学
·
材料科学
·
温敏材料
·
光谱分析
✓ 已验证
DOI
高影响因子
POLYMER
·
2020
·
IF 4.231
Ke Wang,Qi Liu,Guiyan Liu,Yongfei Zeng
The study of thermoresponsive homopolymers has attracted great attention due to their broad application value. Herein, a series of novel thermoresponsive homopolymers of poly[oligo(ethylene glycol) (acyloxy) methacrylate]s containing oligo(ethylene glycol) (OEG) units and substituent groups of ester have been designed and prepared by RAFT polymerization . The solution properties of these polymers have been investigated in detail, which indicate that most of them exhibit lower critical solution temperature (LCST) in water and upper critical solution temperature (UCST) in alcohols, and their LCST-type or UCST-type cloud point temperature ( T CP L or T CP U ) is closely related to the OEG units and ester groups. Furthermore, the parameters affecting the thermoresponse of these polymers including polymerization degree (DP) and concentration have also been investigated. The present work not only discovers a series of novel thermoresponsive polymers, but also has certain guiding significance on the understanding of molecular structure and thermoresponsive property relationships, which is useful for the design of new thermosensitive polymers.
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
Soft Matter
·
2014
·Vol. 11
·期 3
·545-550
·
IF 4.151
Lei Yu,Wenxin Fu,Zhibo Li
Two series of copolymers were prepared by ring-opening polymerization (ROP) of γ-(2-methoxyethoxy)esteryl-L-glutamate (L-EG2Glu) N-carboxyanhydride (NCA) and L-alanine (L-Ala) using HMDS and PEG-NH2 as initiator, respectively. Poly-(L-EG2Glu-co-L-Ala) displayed lower critical solution temperature (LCST) behavior but had a lower phase transition temperature than poly-L-EG2Glu at similar molecular weight (MW). The clouding point (CP) of random copolypeptides can be tuned by altering the alanine content and overall MW. Circular dichroism (CD) and Fourier transform infrared spectroscopy (FTIR) indicated that the thermal-responsive properties depended on the content of ordered conformations. PEG-b-poly-(L-EG2Glu-co-L-Ala) can spontaneously form hydrogels in water at room temperature. Transmission electron microscopy (TEM) and atomic force microscopy (AFM) revealed that these hydrogels were formed by nanoribbons. The intermolecular hydrogen bonding among copolypeptide blocks accounted for the nanoribbon assemblies and hydrogel network formation.
研究领域:
聚合物化学
·
材料科学
·
生物物理学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
RSC Advances
·
2018
·Vol. 8
·期 17
·9334-9343
·
IF 2.936
Hailong Huang,Lifeng Hou,Feng Zhu,Juan Li,Min Xu
A series of controllable thermal and pH dual-responsive copolymeric hydrogels (PMA) were prepared by a one-pot reaction with poly(ethylene glycol) methyl ether acrylate (PEGA), 2-methoxyethyl acrylate (MEA) and acroleic acid (AA). The hydrogels exhibited good mechanical properties and a sensitive response to pH and temperature. Besides, the Lower Critical Solution Temperature (LCST) of the hydrogels can be adjusted from 37 °C to 58 °C by changing the content of AA. The hydrogels also showed excellent selective adsorption properties. The maximum adsorption quantity of organic cationic dye brilliant green and methylene blue were 0.49 mg mg−1 and 0.42 mg mg−1 respectively, much better than previous reports. Furthermore, using the thermal and pH responsibility, the PMA hydrogels can release the adsorbed molecules with control. Nearly 95% of carriers could be released at pH 4.01 and 65 °C over 8 h. The regeneration ability makes the materials easy to reuse many times. Due to these properties, these dual-responsive hydrogels have great potential applications in various fields for adsorption, drug delivery, release and tissue engineering.
研究领域:
材料科学
·
化学工程
·
环境科学
·
生物医学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
·
2017
·Vol. 19
·期 28
·18556-18564
·
IF 4.123
Yalan Dai,Peiyi Wu
A new LCST-type thermoresponsive polyelectrolyte P[P4,4,4,4][SS], poly(tetrabutyl phosphonium styrene sulfonate), was introduced to PMEO2MA (poly(2-(2-methoxyethoxy)ethyl methacrylate)) via RAFT polymerization, in order to explore the transition behavior of the block copolymer PMEO2MA-b-P[P4,4,4,4][SS] with two distinct LCST-type segments. A relatively sharp LCST-type phase transition with only one transition point is observed in the turbidity curves, while the whole phase transition is completely different from the micro perspective. The phase transition temperature range is relatively broad, according to the unsynchronized changes of different protons of the two blocks in the temperature-variable 1H NMR analysis. From PCMW analysis, it is found that there exists an obvious two-step phase transition behavior, especially in the region of the C–H groups. Accordingly, we divided the whole transition process into two subregions: 20–40 °C and 40–55 °C in 2Dcos analysis. At the first stage of 20–40 °C, the CH3 groups mainly belonging to the backbones of PMEO2MA blocks have the earliest response to the heating and drive the first step of the dehydration process of PMEO2MA-b-P[P4,4,4,4][SS], resulting in the formation of an intermediate micelle state composed of the collapsed PMEO2MA core and hydrophilic P[P4,4,4,4][SS] corona. In particular, the conformational changes and the more compact structures due to the interaction between the CO groups and P[P4,4,4,4][SS] segments (ν(CO⋯D2O-PILs)) were observed using IR analysis. With the continual increase of the temperature, when the second temperature range of 40–55 °C is reached, the P[P4,4,4,4][SS] segments start to collapse and expel the water molecules, driven by the anions of the poly(ionic liquid)s, with the phosphonium cations being distributed over the relatively hydrophilic outside.
研究领域:
高分子化学
·
物理化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF MOLECULAR LIQUIDS
·
2023
·
IF 6
Zihao Dong,Yajuan Qu,Yuyang Jiao,Ke Xue,Wenguang Zhu,Hai Liu,Jianguang Qi,Yinglong Wang
A series of poly(1-vinyl-3-methylimidazole dimethyl phosphate- co -N-isopropylacrylamide) oligomers was synthesized by reversible addition-fragmentation chain transfer polymerization. The co-oligomers exhibited a pH-tunable lower critical solution temperature (LCST) phase transition in aqueous solutions. By changing the pH of the aqueous solution (HCI), the hydrogen bonding between the internal molecules of the co-oligomers and water molecules was weakened, which effectively reduced the cloud-point temperature. Poly(1-vinyl-3-methylimidazole dimethyl phosphate- co - N -isopropylacrylamide) oligomers exhibit an upper critical solution temperature (UCST) type of phase transition in an ester solution, which is associated with the formation and breaking of hydrogen bonds within the co-oligomers molecules. FT-IR analysis revealed the effect of temperature on hydrogen bonding between the functional groups. Energy decomposition, Electrostatic Potential (ESP), Atoms-in-Molecules (AIM), and Interaction region indicator (IRI) analyses demonstrated the presence of hydrogen bond donors N–H and imidazole ring C–H, and hydrogen bond acceptors C = O and P = O in the co-oligomers. The sites of hydrogen bonding between the co-oligomers and the solvent molecules as well as intermolecular forces were found to be the main factors contributing to the LCST/UCST-type phase transition.
研究领域:
高分子化学
·
物理化学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）