INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
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2019
·
IF 4.784
Zenghui Cheng,Yupeng Liu,Daihui Zhang,Chuanwei Lu,Chunpeng Wang,Feng Xu,Jifu Wang,Fuxiang Chu
Utilization of natural sustainable feedstock to fabricate polymers has attracted remarkable attention. In this work, we reported a strategy to prepare a series of grafted copolymers from rosin, fatty acids and ethyl cellulose . The process involved the preparation of EC-based macro-RAFT agent through a simple esterification reaction, followed by a “grafting from” reversible addition-fragmentation chain transfer polymerization (RAFT) of DAGMA (derived from rosin) and LMA (derived from fatty acid) to achieve a class of EC- g -P(DAGMA- co -LMA) graft copolymers with a tunable T g tuned by the DAGMA/LMA molar ratio. Then, hexamethylene diisocyanate (HDI) was used to crosslink these graft copolymers. The mechanical and dynamic thermo-mechanical properties of tests showed that elastic recovery values of copolymers were enhanced to 90%, as compared to the un-crosslinked samples. Additionally, all these polymers showed an excellent UV absorption performance. This study provides a facile way to fabricate biobased elastomeric materials with improved mechanical properties.
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高影响因子
Applied Sciences-Basel
·
2019
·Vol. 9
·期 3
·603
·
IF 2.217
Wenzhong Ma,Yuchen Zhao,Zhiwei Zhu,Lingxiang Guo,Zheng Cao,Yanping Xia,Haicun Yang,Fanghong Gong,Jing Zhong
An efficient synthesis route was developed for the preparation of multiwalled carbon nanotube (MWCNT) nanohybrids using azide-terminated poly(methyl methacrylate) (PMMA) via a combination of reversible addition fragmentation chain transfer (RAFT) and the click reaction. A novel azido-functionalized chain transfer agent (DMP-N3) was prepared and subsequently employed to mediate the RAFT polymerizations of methyl methacrylate (MMA). The RAFT polymerizations exhibited first-order kinetics and a linear molecular weight dependence with the conversion. The kinetic results show that the grafting percentage of PMMA on the MWCNTs surface grows along with the increase of the reaction time. Even at 50 °C, the grafting rate of azide-terminated PMMA is comparatively fast in the course of the click reaction, with the alkyne groups adhered to MWCNTs in less than 24 h. The successful functionalization of PMMA onto MWCNT was proved by FTIR, while TGA was employed to calculate the grafting degree of PMMA chains (the highest GP = 21.9%). Compared with the pristine MWCNTs, a thicker diameter of the MWCNTs-g-PMMA was observed by TEM, which confirmed the grafted PMMA chain to the surface of nanotubes. Therefore, the MWCNTs-g-PMMA could be dispersed and stably suspended in water.Keywords:multi-wall carbon nanotube (MWCNT);azide-alkyne click chemistry;RAFT polymerization;PMMA
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NEW JOURNAL OF CHEMISTRY
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2019
·Vol. 43
·期 22
·8517-8526
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IF 3.069
Zhiwu Chen,Hui Cao,Tianwei Tan
A well-defined functional star polymer nanoparticle was prepared using an “arm first” approach via RAFT polymerization. In this work, N-adamantylacrylamide and N-succinimidyl acrylate were copolymerized with N-isopropylacrylamide sucessfully. The obtained diblock copolymer regarded as an “arm” endowed the star polymer with multiple conjugate functions. By adjusting the amount of crosslinking agent, the size and polydispersity of the star polymer were controlled. With the star polymer as the scaffold, a sequential multi-enzyme system was constructed, where HRP was placed in the inner layer through covalent conjugation, and β-cyclodextrin-modified GOx was assembled in the outer layer through host–guest recognition. More interestingly, the activity of the enzyme modified by β-cyclodextrin was improved. In addition to the enhanced thermal stability, this multienzyme system also exhibited a reduced Km value (from 2.18 mM to 0.39 mM) and an excellent substrate affinity. The specificity constant (Kcat/Km) for GOx in the star polymer@HRP@GOx system was 1.7-fold higher than that of the free HRP with free GOx system. This strategy will promote the development of biocatalysis reactions and biosensors as a promising method.
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POLYMER ENGINEERING AND SCIENCE
·
2014
·Vol. 55
·期 1
·8-13
·
IF 1.441
Tian Lan,Wenjie Yang,Juan Peng,Mingke Li,Yinghan Wang
The article aimed to decrease the memory effect of polymer dispersed liquid crystals (PDLCs) films, reversible additional-fragmental chain transfer (RAFT) polymerization was used to synthesize RAFT-polystyrene (RAFT-PS), which was a kind of RAFT macroinitiators and used to prepare PDLCs via photo polymerization induced phase separation (PIPS). Different RAFT agents were used to synthesize RAFT-PS. The effect of photoinitiator concentration on the memory effect of these PDLCs was investigated, and the effect of structures of RAFT macroinitiators on the memory effect of the PDLCs was also discussed. The results showed that PDLC films with higher photoinitiator concentration and polymer matrix which had two rigid chains in two ends showed lower memory effect, which could be reduced from 10.9% to 2.5% in this experiment. POLYM. ENG. SCI., 55:8–13, 2015. © 2014 Society of Plastics Engineers
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EUROPEAN POLYMER JOURNAL
·
2015
·
IF 3.005
Zhongqian Song,Yuanhong Xu,Wenrong Yang,Liang Cui,Jizhen Zhang,Jingquan Liu
A novel tri-block copolymer poly(oxopentanoate ethyl methacrylate)-block-poly(pyridyl disulfide ethyl acrylate)-block-poly(ethylene glycol acrylate) [poly(OEMA-b-PDEA-b-PEGA)], retaining active keto groups and pyridyl disulfide (PDS) side functionalities, was synthesized as a drug delivery vehicle using reversible addition–fragmentation chain transfer (RAFT) polymerization method. One mimic drug pyridine-2-thione (PT) was introduced into the monomer, PDEA for copolymerization. The other mimic drug O-benzylhydroxylamine (BHA) was conjugated with tri-block copolymer via efficient oxime coupling chemistry, followed by the attachment onto graphene via π–π stacking interaction to obtain a graphene/tri-block copolymer composite. 1 H NMR, UV–vis absorption spectroscopy, fluorescence spectroscopy, gel permeation chromatography (GPC), atomic force microscope (AFM) and transmission electron microscope (TEM) were used to verify the successful step-wise preparation of the tri-block copolymer and drug loaded composite. In vitro release behaviors of BHA and PT from graphene/tri-block copolymer composite via dual drug release mechanisms were investigated. BHA can be released under acid environment, while PT will be released in the presence of reducing agents, such as dithiothreitol (DTT) or glutathione (GSH). It can be envisioned that this novel composite could be exploited as a novel intracellular drug delivery system via dual release mechanisms.
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Materials Science & Engineering C-Materials for Biological Applications
·
2016
·
IF 3.42
Cunfeng Song,Shirong Yu,Cheng Liu,Yuanming Deng,Yiting Xu,Xiaoling Chen,Lizong Dai
A methodology to prepare thermo-responsive graft copolymer by using a novel macro-RAFT agent was proposed. The macro-RAFT agent with pendant dithioester (ZC(S)SR) was facilely prepared via the combination of RAFT polymerization and esterification reaction. By means of ZC(S)SR-initiated RAFT polymerization, the thermo-responsive graft copolymer consisting of poly(methyl methacrylate- co -hydroxylethyl methacrylate) (P(MMA- co -HEMA)) backbone and hydrophilic poly(N-isopropylacrylamide) (PNIPAAm) side chains was constructed through the “grafting from” approach. The chemical compositions and molecular weight distributions of the synthesized polymers were respectively characterized by 1 H nuclear magnetic resonance ( 1 H NMR) and gel permeation chromatography (GPC). Self-assembly behavior of the amphiphilic graft copolymers (P(MMA- co -HEMA)- g -PNIPAAm) was studied by transmission electron microscopy (TEM), dynamic light scattering (DLS) and spectrofluorimeter. The critical micelle concentration (CMC) value was 0.052 mg mL − 1 . These micelles have thermo-responsibility and a low critical solution temperature (LCST) of 33.5 °C. Further investigation indicated that the guest molecule release property of these micelles, which can be well described by a first-order kinetic model, was significantly affected by temperature. Besides, the micelles exhibited excellent biocompatibility and cellular uptake property. Hence, these micelles are considered to have potential application in controlled drug delivery.
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JOURNAL OF CHROMATOGRAPHY B-ANALYTICAL TECHNOLOGIES IN THE BIOMEDICAL AND LIFE SCIENCES
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2024
·
IF 2.8
Hongbei Liu,Qiumin Xu,Michael Adu-Frimpong,Yuchu Chen,Ran Li,Fei Xu,Xia Cao,Shanshan Tong
In order to enrich the selection of biological ligands, realize the miniaturization analysis, and broaden the application of monolith materials for active ingredients screening and separating, we sough to construct a lipid raft @capillary monolith microcolumn affinity chromatography model. Single factor experiments and various characterization methods, including scanning electron microscopy (SEM) and thermogravimetric analysis, were employed to investigate the polymerization of the monolith column under different material ratios to determine optimal preparation conditions. Subsequently, the lipid raft from U251 cells was integrated with the monolith materials based on epoxy-based covalent crosslinking principle and characterized through SEM and immunofluorescence methods. Afterwards, the retention of positive drug gefitinib, negative drug gemcitabine and four licorice standards solution on the prepared lipid raft monolith microcolumn was then detected via electrochemical detection. The results exhibited that there was no specific adsorption for any active compounds on the blank monolith materials. Significantly, the lipid raft monolith microcolumn packed with TrkA-target proteins could be successfully validated for positive drug gefitinib with a high affinity sorption efficiency of 51.2%. This work expands the range of the utilization of affinity chromatography carriers and the selection of biological ligands, providing a new idea for the screening of active ingredients.
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Polymers
·
2025
·Vol. 17
·期 4
·515
·
IF 4.9
Yulan Wu,Jie Huang,Zanru Guo,Qian Yang,Chunmiao Xia,Zhenan Zheng
Porous polymer membranes with highly interconnected open-cellular structure and high toughness are crucial for various application fields. Polymerized high internal phase emulsions (polyHIPEs), which usually exist as monoliths, possess the advantages of high porosity and good connectivity. However, it is difficult to prepare membranes due to brittleness and easy pulverization. Copolymerizing acrylate soft monomers can effectively improve the toughness of polyHIPEs, but it is easy to cause emulsion instability and pore collapse. In this paper, stable HIPEs with a high content of butyl acrylate (41.7 mol% to 75 mol% based on monomers) can be obtained by using a composite emulsifier (30 wt.% based on monomers) consisting of Span80/DDBSS (9/2 in molar ratio) and adding 0.12 mol·L−1CaCl2according to aqueous phase concentration. On this basis, polyHIPE membranes with high open-cellular extent and high toughness are firstly prepared via reversible addition–fragmentation chain transfer (RAFT) polymerization. The addition of the RAFT agent significantly improves the mechanical properties of polyHIPE membranes without affecting open-cellular structure. The toughness of polyHIPE membranes prepared by RAFT polymerization is significantly enhanced compared with conventional free radical polymerization. When the molar ratio of butyl acrylate/styrene/divinylbenzene is 7/4/1, the polyHIPE membrane prepared by RAFT polymerization presents plastic deformation during the tensile test. The toughness modulus reaches 93.04 ± 12.28 kJ·m−3while the open-cellular extent reaches 92.35%, and it also has excellent thermal stability.
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Materials Science & Engineering C-Materials for Biological Applications
·
2018
·
IF 5.08
Yanzhu Liu,Liucheng Mao,Saijiao Yang,Meiying Liu,Hongye Huang,Yuanqing Wen,Fengjie Deng,Yongxiu Li,Xiaoyong Zhang,Yen Wei
Amphiphilic copolymers play a paramount role in the fabrication of fluorescent polymeric nanoparticles (FPNs) through the self-assembly procedure. In this work, novel hydrazine hydrate cross-linked amphiphilic poly(PEG‑ co ‑FHMA) copolymers were constructed via reversible addition-fragmentation chain transfer (RAFT) polymerization, containing an aggregation-induced emission (AIE) active hydrophobic moiety and a hydrophilic poly(ethylene glycol) (PEG) group. Different characterization techniques have been employed to confirm their successful synthesis. Due to their amphiphilic property, the resulting poly(PEG‑ co ‑FHMA) copolymers can self-assemble into FPNs in aqueous solution and form poly(PEG‑ co ‑FHMA) FPNs with size ranging from 100 to 200 nm. The investigation of photophysical properties demonstrated poly(PEG‑ co ‑FHMA) FPNs possess strong fluorescence, large Stokes shift, excellent AIE characteristic, low critical micelle concentration and remarkable photostability. Biological assay results suggested that these cross-linked AIE-active FPNs are of low toxicity and excellent cell dyeing performances. All of these features make them promising candidates for biomedical applications. As compared with typical AIE-active FPNs based on the synthetic AIE-active compounds, the novel cross-linked AIE-active FPNs based on the Schiff base is rather simple, good designable and universal. More importantly, this strategy could also be adopted for preparation of a large number of AIE-active FPNs because of the well designability of copolymers and salicylaldehyde derivatives. Thus this work will provide a novel route for preparation of multifunctional AIE-active FPNs in a rather facile manner.
研究领域:
材料科学
·
生物医学工程
·
高分子化学
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Materials Chemistry Frontiers
·
2017
·Vol. 1
·期 6
·1200-1206
·
IF 0
Jiemei Zhou,Chunyan Hong,Caiyuan Pan
A visible light mediated reversible addition–fragmentation chain transfer (RAFT) dispersion polymerization of benzyl methacrylate (BzMA) is conducted in ethanol using poly(2-dimethylaminoethyl methacrylate) (PDMAEMA) as a macro-chain transfer agent (macro-CTA), affording polymeric nanomaterials with various morphologies. Unlike the polymerization-induced self-assembly and reorganization (PISR) process initiated by thermal stimuli, the photo-controlled PISR can be performed under more mild conditions, such as visible light and room temperature. Photoredox catalysis is employed to regulate the polymerization via a photoinduced electron transfer (PET) process. It is observed that the polymerization can be affected by catalyst concentration and light intensity, and “ON/OFF” control over polymerization is also demonstrated.
研究领域:
材料科学
·
高分子化学
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REACTIVE & FUNCTIONAL POLYMERS
·
2019
·
IF 3.074
Junqiang Zhao,Hongrui Han,Qiqi Wang,Chengyou Yan,Dongyang Li,Jing Yang,Xia Feng,Ning Yang,Yiping Zhao,Li Chen
To fabricate hydrophilic and anti-fouling PVDF ultrafiltration membrane, a kind of tailor-made symmetrical amphiphilic triblock copolymer , polyacryloylmorpholine- b -poly (methyl methacrylate)- b -polyacryloylmorpholine (PACMO- b -PMMA- b -PACMO, termed as PAMA), was prepared via RAFT polymerization and employed as an in situ surface segregation modifier. FTIR, 1 H NMR, and GPC were used to verify the well-defined chemical structure of PAMA. The hydrophilic PACMO segments of PAMA were enriched on the surface of membrane skin and interior pores as confirmed by ATR-FTIR, XPS , EDX, and water contact angle tests, endowing the blend membranes with outstanding hydrophilicity . The different cross-sectional and surface morphologies of the PVDF/PAMA blend membranes indicated that the introduction of PAMA modifiers could manipulate membrane structure due to their strong pore-forming ability. Compared with the pure PVDF membrane, PVDF/PAMA blend membranes showed higher permeability for water (28.1 times higher), excellent rejection for bovine serum albumin (up to 98.3%), and enhanced fouling resistance with a higher flux recovery ratio (up to 98.1%). Therefore, the approach of in situ surface segregation employed the RAFT mediated well-defined amphiphilic PAMA triblock copolymer modifiers for the preparation of anti-fouling PVDF membranes showed a great potential in water purification .
研究领域:
材料科学
·
环境工程
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Journal of Macromolecular Science Part B-Physics
·
2024
·
IF 1.2
Tiansheng Gao,Wenzhong Ma,Xiangyuan Song,Jing Zhong,Haicun Yang,Hideto Matsuyama
The application of carbon nanotubes (CNTs) in water treatment membranes can increase the permeability and selectivity of the membranes. However, traditional CNTs are usually affected by van der Waals forces, which makes them prone to agglomerate in polymer membranes, and their non-directional arrangement in the membranes limits their transport efficiency as water channels in the membranes. In this paper, a reversible addition-fragmentation chain transfer (RAFT) polymerization method was used to synthesize propargyl methacrylate - random copolymerization - poly (ethylene glycol) methacrylate - block - polymethyl methacrylate [P(PgMA-r-PEGMA) -b-PMMA]. The P(PgMA-r-PEGMA)-b-PMMA grafting rate was 60.4% on the surface of magnetic sulfhydryl functionalized carbon nanotubes (mCNTs-SH) by click-reaction grafting. Poly (vinylidene fluoride) (PVDF)/CNTs composite ultrafiltration membranes were prepared using vapor-induced phase separation (VIPS) combined with magnetic field arraying. When the mCNTs-g-P(PgMA-r-PEGMA)-b-PMMA were vertically aligned in the PVDF membrane through a magnetic field, the effective construction of the vertical nanochannels was realized, and an increased purified water flux from 25.6 LMH to 35.8 LMH, with the composite ultrafiltration membranes was obtained. In addition, the membranes also showed excellent hydrophilicity, mechanical properties, and polyethylene glycol 1200 (PEG1200) rejection. The water contact angle was reduced from 105° to 79°, the rejection of PEG1200 was increased from 44% to 91% of the 0.5 g/L PEG aqueous solutions, and excellent mechanical properties (tensile strengthes up to 9.3 MPa) were achieved. By designing the interface structure of the CNTs and studying the orientation of the CNTs in PVDF membranes, this work provides a new research idea for the field of water treatment ultrafiltration membranes.
研究领域:
材料科学
·
化学工程
·
高分子科学
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纳米技术
·
环境工程
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