APPLIED SURFACE SCIENCE
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2018
·
IF 4.439
Wenfei Zhou,Mo Yang,Zhi Zhao,Shaopeng Li,Zhiqiang Cheng,Jinsong Zhu
Surface-grafted polymer brushes have been long reported as a desired matrix for biosensing applications, owing to enhanced immobilization capacity and anti-fouling properties. However, simultaneous optimizing binding signal and minimizing non-specific adsorption using polymer matrix is still a challenge, due to the lack of systematic structural and composition optimization at molecular level. In this research, a series of block copolymer brushes with controlled hierarchical architectures, poly [oligo (ethylene glycol) methacrylate- b -glycidyl methacrylate] (POEMGA- b -PGMA) were prepared by two-stage surface-initiated polymerization. Surface plasmon resonance imaging (SPRi), as a real-time and label-free biosensing technology, was used as means to evaluate their detecting performances of bio-interactions. In contrast to one-layer poly (glycidyl methacrylate) (PGMA), 4.7-fold enhancement of signal-to-background ( S / B ) was achieved in bi-layer POEGMA- b -PGMA surface, by using rabbit IgG (R-IgG, in 10% serum) and a microarray of goat-anti-rabbit IgG (G-R-IgG) as the system of study. Interestingly, the binding signals and anti-fouling performances of the polymer brushes could be enhanced simultaneously by increasing the length of the monomer in the primary layer. Theoretically, it mainly owed to the formation of a densely packing protective primary layer against non-specific physical adsorption and a spatially optimized secondary layer of minimized steric hindrance that allowed optimum binding of analytes.
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THERMOCHIMICA ACTA
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2018
·
IF 2.189
Lihong He,Hao Wang,Fan Yang,Hongzhou Zhu
In this study, a series of poly(ethylene glycol) (PEG)/unsaturated polyester resin (UPR)/graphene nanoplates (GNPs) form-stable PCMs (FS-PCMs) were prepared via a simple melt blending method. In this composite, PEG was used as the phase change material for thermal storage, UPR was introduced as a supporting material to prevent the leakage of melted PEG during the phase change transition and the GNPs were selected as conductive fillers to enhance the thermal conductivity of the polymer-based FS-PCMs. The test results demonstrate that the FS-PCMs exhibit an outstanding form-stable performance because of the cross-linked spatial network of UPR. According to the FT-IR and XRD results, no new chemical bonds form among PEG, UPR and the GNPs. The results obtained from TGA and DSC show that the composites possess an excellent thermal stability and a high energy storage density. Moreover, it is also found that the incorporation of GNPs remarkably enhances the thermal conductivity of the prepared FS-PCMs.
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BIORESOURCE TECHNOLOGY
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2018
·
IF 5.807
Naixu Li,Zhongxiang Ji,Lingfei Wei,Yu Zheng,Quanhao Shen,Quanhong Ma,Menglu Tan,Mengmeng Zhan,Jiancheng Zhou
This work studied a facile and template-free hydrothermal route for controlled synthesis of tungsten trioxide in the form of hexagonal nanorod (h-WO 3 ) and monoclinic nanosheet (m-WO 3 ). The surface morphology, crystal plane, surface bound water, and surface acid sites of the two kinds of WO 3 nanocrystals were investigated systematically. They were further evaluated as catalysts for selective cellulose hydrolysis. While both of them exhibited good catalytic performance, h-WO 3 was found to be more preferential for ethylene glycol (EG) generation. This catalytic performance relied on both the unique active crystal surface (1 0 0) and surface binding water (WO 3 -H 2 O) formed by h-WO 3 crystals, which provided more Lewis acid sites for degrading cellulose into EG . Results showed that the highest EG yield reaches 77.5% by a combination of loading 1 wt% Ru on the h-WO 3 catalyst.
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International Journal of Nanomedicine
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2018
·
IF 4.37
Jianwei Duan,Chao Liu,Xiaoyu Liang,Xuanling Li,Youlu Chen,Zuoguan Chen,Xiaoli Wang,Deling Kong,Yongjun Li,Jing Yang
Background To address the issue of delivery of proteins, a six-arm copolymer, six-arm poly (ε-caprolactone)–poly(ethylene glycol) (6S-PCL-PEG), was synthesized by a simple two-step reaction. Thereafter, the application of 6S-PCL-PEG as a protein carrier was evaluated. Materials and methods A six-arm copolymer, six-arm poly(ε-caprolactone) (6S-PCL), was synthesized by ring-opening polymerization, with stannous octoate as a catalyst and inositol as an initiator. Then, poly(ethylene glycol) (PEG) was linked with 6S-PCL by oxalyl chloride to obtain 6S-PCL-PEG. Hydrogen-1 nuclear magnetic resonance spectrum, Fourier-transform infrared spectroscopy, and gel-permeation chromatography were conducted to identify the structure of 6S-PCL-PEG. The biocompatibility of the 6S-PCL-PEG was evaluated by a cell counting kit-8 assay. Polymeric nanoparticles (NPs) were prepared by a water-in-oil-in-water double emulsion (W 1 /O/W 2 ) solvent evaporation method. The size distribution and zeta potential of NPs were determined by dynamic light scattering. Transmission electron microscopy was used to observe the morphology of NPs. Drug-loading capacity, encapsulation efficiency, and the release behavior of ovalbumin (OVA)-loading NPs were tested by the bicinchoninic acid assay kit. The stability and activity of OVA released from NPs were detected and the uptake of NPs was evaluated by NIH-3T3 cells. Results All results indicated the successful synthesis of amphiphilic copolymer 6S-PCL-PEG, which possessed excellent biocompatibility and could formulate NPs easily. High drug-loading capacity and encapsulation efficiency of protein NPs were observed. In vitro, OVA was released slowly and the bioactivity of OVA was maintained for over 28 days. Conclusion 6S-PCL-PEG NPs prepared in this study show promising potential for use as a protein carrier.
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INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
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2018
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IF 3.909
Xuechuan Wang,Ke Chen,Wei Li,Dongyan Hao,Peiying Guo
In this research, collagen hydrolysates with different average molecular weights ( Mn ¯ ) from leather collagen were chosen as raw materials. Five environmental-friendly sizing agents (SA) were prepared by cross-linking collagen hydrolysates with glycol diglycidyl ether (GDE) and further grafting them with butyl acrylate (BA) and styrene (St). Then the compound sizing agents (SGDESA-x, x = 1, 2, 3 and 4) were obtained by simple physical mixing of GDESA and starch. The surface sizing performance of GDESA and compound sizing agents were studied. The research result shows that both physical, mechanical properties and water resistance of the corrugated paper coated by GDESA were significantly improved when Mn ¯ of collagen hydrolysate was about 10,000, and its emulsion exhibited robust stability in long standing time. Furthermore, when the SGDESA-2 was used as a sizing agent, the coated corrugated paper exhibited strong water resistance, good physical and mechanical properties even after refolded for 20 times.
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TALANTA
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2018
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IF 4.244
Xiao Sun,Jing Li,Li Xu
In the present study, the narrow-dispersed penetrable poly(methacrylic acid- co -ethylene glycol dimethacrylate) (poly(MAA- co -EDMA)) microspheres were successfully synthesized based on the sacrificial support method. The poly(MAA- co -EDMA) microspheres mirrored the porous structure of the sacrificial support, i.e. penetrable silica, characteristic of copious mesopores and throughpores. In addition, they possessed large surface area, adjustable hydrophobicity and the cation-exchange ability. Owing to their multi functionalities, they were applied as chromatographic stationary phase to separate proteins in different separation modes, including reversed phase, hydrophobic interaction and weak cation exchange. Moreover, thanks to their throughpores, fast separation at low column backpressure could be achieved in these three modes. Both protein recovery and column stability were satisfactory. The penetrable poly(MAA- co -EDMA) microspheres were potential stationary phase matrix for fast protein separation.
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MACROMOLECULAR CHEMISTRY AND PHYSICS
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2013
·Vol. 214
·期 7
·824-834
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IF 2.386
Lidong Feng,Xinchao Bian,Yi Cui,Zhiming Chen,Gao Li,Xuesi Chen
Poly( L -lactide) (PLLA) is melt blended with poly(ether urethane) (PEU) based on poly(ethylene glycol) blocks via a chain-extension reaction by diisocyanate as a chain extender to improve its flexibility without sacrificing comprehensive performance. The elongation at break of the blends with triphenyl phosphate (TPP) as a reactive blending additive is much higher than that without TPP by physical blending. When 10 wt% PEU is blended, the former elongation reaches to 298%, while the latter one is only approximately 20%. The reactive blending forms a PLLA–PEU block copolymer, thus improving their compatibility. When the weight-average molecular weight ( M w ) of PEUs is 18–90 kg mol −1 , the effect of M w is very little on tensile properties of blends. The rheological properties of the blends are modified through the content and molecular weight of PEU. The complex viscosity ( η *) of PLLA/PEU blends increases with increasing M w of PEU. The η * of the PLLA blend containing 5 wt% PEU in M w 73 kg mol −1 is higher than that of neat PLLA. The water absorption of the PLLA/PEU blends enhances because of the hydrophilicity of PEUs versus neat PLLA.
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JOURNAL OF POLYMER SCIENCE PART A-POLYMER CHEMISTRY
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2013
·Vol. 52
·期 2
·188-199
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IF 3.543
Yan Zhang,Jinhong Li,Zhengzhen Du,Meidong Lang
pH-responsive methoxy poly(ethylene glycol)- b -poly(ε-caprolactone) bearing pendant carboxyl groups mPEG- b -P(2-CCL- co -6-CCL) was synthesized based on our newly monomer benzyloxycarbonylmethly functionalized ε-caprolactone. Their structure was confirmed by 1 H NMR, 13 C NMR, and Fourier transform infrared spectrum spectra. In addition, SEC results indicated that the copolymers had a relatively narrow polydispersity. WXRD and DSC demonstrated that the introduction of carboxymethyl groups had significant effect on the crystallinity of the copolymers. Furthermore, the solution behavior of mPEG- b -P(2-CCL- co -6-CCL) has been studied by various methods. The results indicated that mPEG- b -P(2-CCL- co -6-CCL) had a rich pH-responsive behavior and the micelles could be formed by pH induction, and the mPEG- b -P(2-CCL- co -6-CCL) could existed as unimers, micelles or large aggregates in different pH range accordingly. The mechanism of which was supposed to depend on the counteraction between the hydrophobic interaction from PCL and the ionization of the carboxyl groups along the polymer chain. Moreover, the mPEG- b -P(2-CCL- co -6-CCL) copolymers displayed good biocompatibility according to the preliminary cytotoxicity study. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014 , 52 , 188–199
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CARBON
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2015
·
IF 6.196
Guo-Qiang Qi,Jie Yang,Rui-Ying Bao,Zheng-Ying Liu,Wei Yang,Bang-Hu Xie,Ming-Bo Yang
The design and preparation of high comprehensive performance composite phase change materials (PCMs) via a straightforward route were pioneered. Graphene oxide (GO) nanosheets were introduced as supporting materials to keep the shape of polyethylene glycol (PEG) stable during the phase change process and graphene nanoplatelets (GNP) were used as conductive fillers to improve the thermal conductivity and electrical conductivity. The comprehensive performance and structure–property relationships of composite PCMs with hybrid graphene nanomaterials were investigated by means of various characterization techniques. The PEG/GO/GNP composite PCM with only 2 wt% GO and 4 wt% GNP hybrid fillers exhibited superior comprehensive performance: thermal energy storage density as high as 98.2% of pure PEG, shape stabilization effect, high thermal conductivity of 1.72 W/mK (more than 490% increase over pure PEG), high electrical conductivity of 2.5 S/m and excellent thermal reliability after thermal cycling. The incorporated GO and GNP were proved to be effective supporting materials and conductive materials respectively, and also played an important role in improving the phase change enthalpy of PEG. Furthermore, GO also contributed to the enhancement of thermal conductivity but acted as barriers in the conductive path. The present study represents an important step toward developing high comprehensive performance composite PCMs.
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RSC Advances
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2015
·Vol. 5
·期 63
·50955-50961
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IF 3.84
Yong Xia,Hongtao Yao,Zhihui Miao,Yun Ma,Meifang Cui,Liqiang Yan,Huanhuan Ling,Zhengjian Qi
We demonstrate here a facile and efficient synthesis of polysiloxane-based amphiphilic copolymers via thiol-ene click chemistry. The properties of PEG-b-PDMS-b-PEG (T-PPG) and PDMS-g-PEG (S-PPG20 and S-PPG100) amphiphilic copolymers were studied in detail by a combination of 1H NMR, FT-IR, gel permeation chromatography, and thermogravimetric analysis. In comparison with the traditional hydrosilylation method which requires the noble metal catalyst platinum, the newly designed thiol-ene protocol produces polysiloxane-based amphiphilic copolymers with only anti-Markovnikov addition products under benign conditions. The resulting copolymers have lower critical aggregation concentration (CAC), and dynamic light scattering (DLS) results revealed that the obtained amphiphilic copolymers can self-assemble into nanoparticles (128 nm to 198 nm) in aqueous solutions with a narrow size distribution (PDI is less than 0.24).
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RSC Advances
·
2014
·Vol. 4
·期 43
·22520-22525
·
IF 3.708
Yong Liu,Yi-Tao Wang,Tao Liu,Duan-Jian Tao
SO3H-functionalized Brønsted acidic ionic liquids (BAILs) were synthesized and utilized as highly efficient catalysts for the production of fructone via the acetalization reaction of ethyl acetoacetate with ethylene glycol. In comparison with conventional H2SO4 and cation exchange resins, the BAILs N-(4-sulfonic acid) butyl triethylammonium hydrogensulfate ([BSEt3N][HSO4]) of strong acidities exhibited excellent catalytic activities. The effects of various parameters such as different BAILs, reaction temperature, catalyst dosage, and molar ratio of the reactants on the conversion of ethyl acetoacetate were investigated in detail. The experimental results indicated that the catalytic performance of BAILs were closely related to their Hammett acidities. Moreover, it was found that [BSEt3N][HSO4] could be also recovered easily and used repetitively six times without obvious decline in activity and quantity, showing great potential application in industry.
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BIOMATERIALS
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2013
·
IF 7.604
Xiangsheng Liu,Nan Huang,Haibo Wang,Huan Li,Qiao Jin,Jian Ji
Multidentate ligands are expected to improve the performance of inorganic nanoparticles (NPs) in biological application. Designing robust multidentate ligands by a facile way and understanding the impact of ligand composition on NP's property are greatly important. We report the effective synthesis of hydrophilic copolymers containing pendent thiol groups along a polyethylene glycol (PEG) methacrylate backbone by classical free radical copolymerization . Gold nanoparticles (AuNPs) coated by these multidentate ligands with two different ratios of thiols to PEG segment (∼1:1 and 1:2) showed much higher colloidal stability in the presence of dithiothreitol (DTT) than AuNPs coated by monothiol-anchored PEG, and AuNPs coated by ligands with higher fraction of thiol groups showed slightly better resistance to DTT competition than did AuNPs coated by ligands with lower thiol fraction, but both of them exhibited excellent stabilities in biological media without obvious difference. In vitro study of uptake by macrophages did not showed significant difference between the two AuNPs with very low endocytosis . However, AuNPs coated by ligands with higher PEG content were found to accumulate in liver with a significantly lower level but a higher level in spleen than AuNPs coated by ligands with lower PEG contents. Moreover, the AuNPs coated with by ligands with higher PEG content showed higher tumor uptake. Additionally, AuNPs coated with both ligands demonstrated good biocompatibility as evaluated by cytotoxicity assays and histological analysis . Together, the composition of multidentate ligands will not only affect the stability of NPs under extreme conditions but also result in quite different fate of NPs in vivo, which can be tailored case by case.
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