APPLIED SURFACE SCIENCE
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2014
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IF 2.538
Zhiping Du,Xiaofeng Sun,Xiumei Tai,Guoyong Wang,Xiaoying Liu
Thermosensitive poly(ethylene glycol) methyl ether methacrylate (POEGMA) was grafted on SiO 2 nanoparticles using activators generated by electron transfer atom transfer radical polymerization (AGET-ATRP) technique. The effects of the amount of ligand, catalyst, ascorbic acid and monomer, as well as the reaction temperature and time were systematically investigated and optimized to get a high grafting density. The structure of the hybrid materials was characterized by Fourier transform infrared (FTIR) spectroscopy, and the morphology was characterized by transmission electron microscopy (TEM) observations. Thermosensitive properties of SiO 2 -POEGMA particles were investigated at different grafting densities by turbidity measurements.
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
SURFACE AND INTERFACE ANALYSIS
·
2016
·Vol. 49
·期 4
·316-322
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IF 1.018
Qian Zhang,Jun-Jiao Yin,Feng Liu,Xue-Na Zou,Li-Qiang Chu
Surface-enhanced Raman scattering (SERS) has attracted a great deal of interest during the past four decades and emerged as an ultrasensitive optical technique for chemical and biomedical analysis. It is widely accepted that the facile fabrication of SERS substrates with high activity and good reproducibility is of crucial importance for their applications. Herein, we report on a fast and robust method for the synthesis and immobilization of silver nanoparticles (AgNPs) into poly(oligo(ethylene glycol) methacrylate) (POEGMA) brushes under mild conditions without using any reducing agents. POEGMA brushes of different chain lengths were synthesized directly on silicon wafers by surface-initiated atom transfer radical polymerization with various reaction time. X-ray photoelectron spectroscopy and field emission scanning electron microscope measurements indicated that the AgNPs were firmly and homogeneously embedded into POEGMA brushes. The resulting POEGMA–AgNP hybrid films were employed as SERS substrates for the detection of 4-aminothiophenol, giving rise to an enhancement factor of up to 1.9 × 10 6 . The influence of the POEGMA's chain length on SERS performance was also investigated. Copyright © 2016 John Wiley & Sons, Ltd.
研究领域:
材料科学
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分析化学
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产品关联
DOI
高影响因子
ACS SYMPOSIUM SERIES
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2012
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IF 0
Pingwei Liu,Weiqiang Lu,Wen-Jun Wang,Bo-Geng Li,Zhibin Ye,Shiping Zhu
Amphiphilic diblock copolymers consisting of linear or hyperbranched polyethylene (PE) and poly[oligo (ethylene glycol) methyl ether methacrylate] (POEGMA) were synthesized via atom transfer radical polymerization (ATRP) initiated by PE macroinitiators (MIs). The MIs contained an end-capping 2-bromoisobutyryl group per chain. Their linear and hyperbranched structures were first synthesized through a ‘‘living’’ polymerization of ethylene under pressure of 27.6 and 1 atm, respectively, using Pd–diimine catalyst, [(ArN=C(Me)–(Me)C=NAr)Pd(CH2)3C(O)O(CH2)2OC(O)C(CH3)2Br]+ SbF6− (Ar = 2,6-(iPr)2C6H3) (1). In the ATRP of OEGMA, the effect of solvent, ligand, and MI concentration on the block copolymer formation were studied. The macroinitiator and block copolymer samples were characterized by GPC, 1H NMR, and DSC measurements. All samples possessed well-defined topologies/structures with narrow molecular weight distributions and controlled lengths of PE and POEGMA blocks. The block structures were verified by an intrinsic viscosity study. Micelle formation and its temperature sensitivity were also analyzed by dynamic light scattering.
研究领域:
高分子化学
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材料科学
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DOI
LANGMUIR
·
2012
·
IF 4.186
Xiujuan Shi,Yanyun Wang,Dan Li,Lin Yuan,Feng Zhou,Yanwei Wang,Bo Song,Zhaoqiang Wu,Hong Chen,John L. Brash
It is well known that adsorbed proteins play a major role in cell adhesion. However, it has also been reported that cells can adhere to a protein-resistant surface. In this work, the behavior of L02 and BEL-7402 cells on a protein-resistant, 3D topographical surface was investigated. The topographical gold nanoparticle layer (GNPL) surfaces were prepared by chemical gold plating, and the topography was described by roughness parameters acquired from a multiscale analysis. Both smooth Au and GNPL surfaces were modified with POEGMA polymer brushes using surface-initiated ATRP. The dry and hydrated thicknesses of POEGMA brushes on both smooth and rough surfaces were measured by AFM using a nanoindentation method. Protein adsorption experiments using 125I radiolabeling revealed similarly low levels of protein adsorption on smooth and GNPL surfaces modified with POEGMA, thus allowing an investigation of the effects of topography on cell behavior under conditions of minimal protein adsorption. The roles of VN and FN adsorption in both L02 cells and BEL-7402 cells adhesion were investigated using cell culturing with and without a serum supplement. It was found that initial cell adhesion occurred via proteins adsorbed from the cell culture medium, whereas subsequent durable cell adhesion could be attributed to the topographical structure of the surface. Although cell spreading on protein-resistant surfaces was constrained because of the lack of adsorbed proteins, we found that cells adherent to topographical surfaces were more firmly attached and thus were more durable compared to those on smooth surfaces. In general, however, we conclude that topography is more important for cell adhesion on a protein-resistant surface.
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DOI
PubMed
高影响因子
LANGMUIR
·
2017
·
IF 3.833
Yong Du,Jingyao Gao,Tingting Chen,Chao Zhang,Jian Ji,Zhi-Kang Xu
Poly(oligoethylene glycol methacrylate) (POEGMA) and zwitterionic polymer brushes have been widely used for constructing biocompatible or antifouling surfaces, and their oxidative stability is very important to the practical application. Herein, POEGMA, poly(sulfobetaine methacrylate) (PSBMA), poly(2-(methacryloyloxy)ethyl phosphorylcholine) (PMPC), and poly(carboxybetaine methacrylate) (PCBMA) were grafted on quartz crystal microbalance (QCM) chips via surface-initiated atom transfer radical polymerization (SI-ATRP). XPS and MS analyses demonstrate that the mass loss of these polymer brushes in oxidative environment is due to the scission of the polymer-anchoring segments. Molecular simulation further illustrates this mass loss mechanism should be always true for those polymer brushes anchored on different substrates. In situ QCM monitoring indicates that, compared with zwitterionic polymethacrylates, POEGMA brushes show the lowest mass loss rate mainly due to their cross-linked structures. This study sheds light on the contradictory reports about the oxidative stability of POEGMA and zwitterionic polymethacrylate brushes up to now, and highlights the important role of the polymer-anchoring segments playing in the oxidative stability of polymer brushes.
研究领域:
材料科学
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生物医学工程
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DOI
高影响因子
JOURNAL OF MEMBRANE SCIENCE
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2018
·
IF 6.578
Jindan Wu,Wei Wei,Shihong Li,Qi Zhong,Fu Liu,Jinhuan Zheng,Jiping Wang
The effect of membrane surface charge on demulsification and fouling resistance during emulsion separation is investigated. By grafting poly(2-dimethylaminoethyl methacrylate) (pDMAEMA) and poly(oligo(ethylene glycol) methacrylate) (pOEGMA) onto polypropylene (PP) membrane via ultraviolet (UV)-initiated polymerization, the obtained membranes PP- g -pDMAEMA and PP- g -pOEGMA present positive and negative surface charges in water, respectively. During the emulsion separation, PP- g -pOEGMA and PP- g -pDMAEMA membranes exhibit different separation efficiencies and pollutant resistant behaviors to the emulsions prepared from anionic surfactant (sodium dodecyl sulfate, SDS) and cationic surfactant (cetyltrimethylammonium bromide, CTAB). Comparing to PP- g -pOEGMA, the separation efficiency of PP- g -pDMAEMA was 15% (SDS emulsion) and 300% (CTAB emulsion) higher. But the flux recovery ratio of PP- g -pOEGMA was raised 30% (SDS emulsion) and 16% (CTAB emulsion). Hence, the membrane surface positive charges assist demulsification, but aggravate the membrane fouling . The mechanism obtained is beneficial to construct membranes with high separation efficiency and long-term durability.
研究领域:
材料科学
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环境工程
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DOI
高影响因子
Polymer Chemistry
·
2016
·Vol. 7
·期 14
·2476-2485
·
IF 5.687
Sheng-Qi Chen,Chen He,Hui-Juan Li,Peng-Yun Li,Wei-Dong He
A self-assembly mediated synthesis was successfully adopted in the preparation of Janus long-chain hyperbranched copolymers composed of polystyrene (PSt) and poly[oligo(ethylene glycol) methacrylate] (POEGMA) half-dendrons. Firstly, seesaw macromonomers with one alkynyl group at the chain center and one azido group at each chain end, [alkynyl-(PSt-N3)2 and alkynyl-(POEGMA-N3)2], were prepared through atom transfer radical polymerization and used to produce their own long-chain hyperbranched homopolymers (lhb-PSt and lhb-POEGMA) through a click reaction, followed by the conversion of azido end-groups into amino end-groups. Meanwhile, one hetero four-arm copolymer of μ-PSt2-POEGMA2 with four azido end-groups was obtained by the sequential click reaction of alkynyl-(PSt-Br)2 and alkynyl-(POEGMA-Br)2 with α,ω-diazido tetra(ethylene glycol) and the conversion of bromo groups into azido groups. Finally, with the help of self-assembly in different selective solvents, lhb-POEGMA and lhb-PSt were linked alternately onto μ-PSt2-POEGMA2 through click chemistry, resulting in a Janus long-chain hyperbranched copolymer [μ-(lhb-POEGMA)(lhb-PSt)]. The different analytical techniques confirmed the successful preparation of μ-(lhb-POEGMA)(lhb-PSt) and its different precursors. The self-assembly behavior of different amphiphilic copolymers was investigated by TEM, DLS and DSC. The variation of the contact angle of μ-(lhb-POEGMA)(lhb-PSt) with the casting solvent was correlated with its self-assembly behavior in selective solvents.
研究领域:
高分子化学
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材料科学
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纳米技术
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产品关联
DOI
高影响因子
Journal of Energy Storage
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2019
·
IF 3.517
Linghong Xu,Guibin Li,Jianxin Guan,Lulu Wang,Jitao Chen,Junrong Zheng
Solid polymer electrolytes are promising candidates to replace the extensively used flammable liquid electrolytes in lithium batteries. However, pure polymer electrolytes seldom meet practical requirements because of their relatively low ionic conductivity and poor mechanical properties. Herein, we report a garnet (Li 6.4 La 3 Zr 1.4 Ta 0.6 O 12 , LLZTO)-doped composite polymer electrolyte (CPE) membrane for high performance lithium batteries. The CPE is composed of poly(vinylidene fluoride- co -hexafluoropropylene) (PVDF-HFP) and poly(ethylene glycol) methyl ether methacrylate (POEGMA) polymer with the addition of ceramic particles LLZTO. It not only has high ionic conductivity of 1.00 × 10 −3 S cm −1 after the activation of liquid electrolyte at room temperature, but also surprisingly restrains the growth of Li dendrites. Its electrochemical stability window is up to 4.7 V (vs. Li + /Li). Moreover, LiFePO 4 /Li batteries using the CPE exhibit excellent cycling performance and superior rate capability.
研究领域:
材料科学
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电化学
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电池技术
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产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2013
·
IF 5.008
Yanyun Wang,Feng Zhou,Xiaoli Liu,Lin Yuan,Dan Li,Yanwei Wang,Hong Chen
For potential applications in the isolation and enrichment of circulating tumor cells (CTCs), we have developed gold nanoparticle layers (GNPLs) of different roughness modified with TD05 aptamers (GNPL-APT). In serum-free binary cell mixtures containing Ramos cancer cells and CEM cells, the density of Ramos cells adherent to highly rough GNPL-APT was 19 times that of CEM cells. However, in serum-containing conditions, the specificity of GNPL-APT for Ramos cells was much reduced. To improve Ramos specificity in the presence of serum, we attached the TD05 aptamer to the layers via poly(oligo(ethylene glycol) methacrylate) (POEGMA) as an antifouling spacer (GNPL-POEGMA-APT). In serum-containing environment GNPL-POEGMA-APT showed an enhanced selectivity for Ramos cells, which increased with increasing surface roughness. The results of this study indicate that surfaces combining appropriate chemical composition and micro/nano roughness structures may be useful for cell separation, including the isolation of cancer cells for diagnosis.
研究领域:
生物材料
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生物医学工程
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癌症诊断
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纳米技术
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细胞生物学
✓ 已验证
DOI
PubMed
高影响因子
LAB ON A CHIP
·
2023
·Vol. 23
·期 10
·2477-2486
·
IF 6.1
Xiaoyi Li,Zhihao Feng,Changxiang Fang,Yunpeng Wei,Dandan Ji,Weihua Hu
Oblique-incidence reflectivity difference (OIRD) is a compelling technique for real-time, label-free and non-destructive detection of antibody microarray chips, but its sensitivity needs essential improvement for clinical diagnosis. In this study, we report an innovative high-performance OIRD microarray by using poly[oligo(ethylene glycol) methacrylate-co-glycidyl methacrylate] (POEGMA-co-GMA) brush grafted fluorine-doped tin oxide (FTO) as the chip substrate. The polymer brush enhances the interfacial binding reaction efficiency of targets from the complicated sample matrix due to its high antibody loading and excellent anti-fouling merits; the FTO-polymer brush layered structure, on the other hand, excites the interference enhancement effect of OIRD to achieve enhanced intrinsic optical sensitivity. Synergistically, the sensitivity of this chip is significantly improved compared to rival chips, achieving a limit of detection (LOD) as low as 25 ng mL−1 for the model target C-reactive protein (CRP) in 10% human serum. This work explores the tremendous influence of the chip interfacial structure on the OIRD sensitivity and proposes a rational interfacial engineering strategy to boost the performance of the label-free OIRD based microarray and other bio-devices.
研究领域:
材料科学
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生物医学工程
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分析化学
·
光学
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产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）