EUROPEAN POLYMER JOURNAL
·
2014
·
IF 3.242
Houluo Cong,Jingang Li,Lei Li,Sixun Zheng
In this contribution, we reported the synthesis of poly(N-isopropylacrylamide)- block -poly(N-vinylpyrrolidone)- block -poly(N-isopropylacrylamide) (PNIPAM- b -PVP- b -PNIPAM) triblock copolymers through sequential reversible addition–fragmentation chain transfer/macromolecular design via the interchange of xanthate (RAFT/MADIX) process. The triblock copolymers have been characterized by means of 1 H nuclear magnetic resonance (NMR) spectroscopy, gel permeation chromatography (GPC) and differential scanning calorimetry (DSC). This ABA triblock copolymer displayed a typical thermoresponsive gelation behavior. In this work, the thermoresponsive gelation behavior was investigated by means of rheological measurements, micro-differential scanning calorimetry (Micro-DSC) and small angle X-ray scattering (SAXS). The thermoresponsive gelation behavior could endow the triblock copolymers with the potential application as injectable hydrogels.
研究领域:
高分子化学
·
材料科学
·
生物医学工程
✓ 已验证
产品关联
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2022
·
IF 7.392
Wantang Wang,Baoguo Zhang,Yunhui Shi,Dengke Zhou,Ru Wang
The dispersion stability of alumina suspensions is an obstacle to its large-scale application for chemical mechanical polishing (CMP) since the aggregation of particles will cause scratches on the wafer surface during polishing. Therefore, this study was devoted to improving the physicochemical properties of alumina suspensions using different polymeric dispersants, including polyethylene glycol (PEG) with nonionic properties, sodium polyacrylate (PAAS) with anionic properties, and their triblock copolymer poly(acrylic acid)- b -PEG- b -poly(acrylic acid) (PAEG). The characterization results of dispersion stability showed that, compared with PEG and PAAS, the suspensions containing a suitable dosage of PAEG exhibited the advantages of low-viscosity (Viscosity < 3 mPa·s), good-stability (Zeta potential < -50 mV), and monodisperse (Polydispersity index < 0.1). The adsorption isotherm indicated that the adsorption of dispersants on alumina particles was consistent with Langmuir model. Furthermore, the total potential energy between particles in suspension was calculated for theoretical analysis of the inter-particle interactions. Besides, the dispersion mechanisms of PEG, PAAS, and PAEG were proposed as steric stabilization, electrostatic stabilization and electrosteric stabilization, respectively. Finally, CMP experiments showed that the suspension prepared by using PAEG as a dispersant to polish SiC substrates resulted in better removal rates (382 nm/h) and lower surface roughness ( Ra : 1.85 nm).
研究领域:
材料科学
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化学工程
·
表面工程
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产品关联
DOI
高影响因子
JOURNAL OF NANOSCIENCE AND NANOTECHNOLOGY
·
2021
·Vol. 21
·期 4
·2174-2184
·
IF 0
Zhang Diansen,Xia Yuzheng,Gong Hongliang,Zhang Dong,Chen Xiaonong,Shi Shuxian,Lei Lei
Polylactide-b-poly(N-isopropylacrylamide)-b-polystyrene (PLA-b-PNIPAM-b-PS) triblock copolymers (tri-BCPs) with various chemical compositions (block ratio) were prepared from the combination of ring-opening polymerization and reversible addition-fragmentation
chain transfer polymerization. Subsequently, the self-assembling behaviors of these tri-BCP films obtained from spin-coating were investigated by annealing them under different solvent atmosphere. We found that these films could self-assemble into various morphologies due to the microphase
separation of incompatible copolymer blocks. Atomic force microscopy confirmed the perpendicular cylindrical morphology self-assembled from PLA4.5k-b-PNIPAM5.2k-b-PS22.4k tri-BCP film under mixed solvent atmosphere of toluene/acetone (7:3, v/v).
Self-assembled PLA cylinders are evenly distributed among the PS matrix and perpendicular to the film surface, with PNIPAM component taking place at the PLA/PS interphase. Furthermore, by etching the degradable PLA component, porous PS film decorated with PNIPAM “brushes” hoisting
channels were generated. This work provides a facile method and detailed protocol for fabricating stimuli-responsive porous films which are promising for thermoresponsive “smart” separation technologies.
研究领域:
材料科学
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高分子化学
·
纳米技术
✓ 已验证
DOI
PubMed
JOURNAL OF APPLIED POLYMER SCIENCE
·
2015
·Vol. 132
·期 18
·
IF 1.768
Yan-Ling Luo,Jun Zhang,Fang-Jie Han,Feng Xu,Ya-Shao Chen,Ru Liu
Thermoresponsive poly( N -isopropyl acrylamide) (PNIPAM)- block -hydroxy-terminated polybutadine- block -PNIPAM triblock copolymers were synthesized by atom transfer radical polymerization; this was followed by the in situ epoxidation reaction of peracetic acid. The copolymers were characterized by 1 H-NMR, Fourier transform infrared spectroscopy, and size exclusion chromatography measurements, and their physicochemical properties in aqueous solution were investigated by surface tension measurement, fluorescent spectrometry, ultraviolet–visible transmittance, transmission electron microscopy observations, dynamic light scattering, and so on. The experimental results indicate that the epoxidized copolymer micelle aggregates retained a spherical core–shell micelle structure similar to the control sample. However, they possessed a decreased critical aggregate concentration (CAC), increased hydrodynamic diameters, and a high aggregation number and cloud point because of the incorporation of epoxy groups and so on. In particular, the epoxidized copolymer micelles assumed an improved loading capacity and entrapment efficiency of the drug, a preferable drug-release profiles without an initial burst release, and a low cytotoxicity. Therefore, they were more suitable for the loading and delivery of the hydrophobic drug as a controlled release drug carrier. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132 , 41877.
研究领域:
材料科学
·
药学
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DOI
高影响因子
CHEMICAL RESEARCH IN CHINESE UNIVERSITIES
·
2014
·Vol. 30
·期 5
·863-867
·
IF 1.119
Wang Huan,Yao Yuan,Han Lu,Che Shun’ai
Self-assembled triblock terpolymers have attracted intense attention in recent years because of their abundant variety of assembly mesostructure. We reported the synthesis of mesoporous silica materials with the amphiphilic ABC triblock terpolymer polyethylene-poly(ethylene oxide)-polycaprolactone(PE-PEO-PCL) as a template and tetraethoxysilane(TEOS) as a silica source. Increasing the hydrophilic head group(PEO) led to the decrease of packing parameter g , which gave rise to the mesophase transformation from a cylindrical two-dimensional hexagonal P 6 mm structure to a cage-type face centered cubic closed-packing mesostructure. This new templating route provided a new insight into the template factor governed inorganic-organic self-assembly mesophases.
研究领域:
材料科学
·
化学
✓ 已验证
DOI
高影响因子
Materials Science & Engineering C-Materials for Biological Applications
·
2017
·
IF 4.164
Xueli Wang,Changyu He,Qinglai Yang,Lianjiang Tan,Bingya Liu,Zhenggang Zhu,Bing Gong,Yu-Mei Shen
Redox-responsive linkages dispersed in the backbones of the synthetic polymers, while young in the current spectrum of the biomedical application, are rapidly extending into their niche. In the present work, triblock copolymer PEG-PLA-PEG synthesized and characterized by 1 H -NMR and SEC can self-assemble into redox-responsive micelles in aqueous media with nanosized 33 nm and 47 nm. And the copolymers PEG 2000 -PLA 3000 -PEG 2000 and PEG 2000 -PLA 5000 -PEG 2000 present lower CMC with 0.034 and 0.022 mg/mL, and higher DLC of 4.28% and 5.14% respectively, compared with that of diblock copolymer. Moreover, drug release from the micelles can be triggered and significantly accelerated in reductive environment. The low cytotoxicity of redox-responsive micelles was confirmed by MTT assay against NIH 3 T3 cells. All of these results demonstrated that these polymeric micelles self-assembled from double-disulfide tethered block copolymers are promising carriers for the redox-responsive intracellular delivery of hydrophobic anticancer drugs.
研究领域:
生物材料
·
药剂学
·
高分子化学
✓ 已验证
DOI
高影响因子
JOURNAL OF PHYSICAL CHEMISTRY B
·
2011
·
IF 3.603
Jiucun Chen,Mingzhu Liu,Honghong Gong,Yinjuan Huang,Chen Chen
A well-defined thermoresponsive poly(ethylene glycol)-block-poly(N-isopropylacrylamide)-block-poly(ε-caprolactone) (PEG43-b-PNIPAM82-b-PCL87) triblock copolymer was synthesized by combination of atom transfer radical polymerization (ATRP), ring-opening polymerization (ROP), and click chemistry. The synthesis included the four steps, and all the structures of the polymers were determined. The thermoresponsive triblock copolymer can disperse in water at room temperature to form core–shell–corona micelles with the hydrophobic PCL block as core, the thermoresponsive PNIPAM block as shell, and the hydrophilic PEG block as corona. At temperatures above the lower critical solution temperature (LCST) of the PNIPAM block, the PNIPAM chains gradually collapse on the PCL core to shrink the size and change the structure of the resultant core–shell–corona micelles with temperature increasing.
研究领域:
材料科学
·
高分子化学
✓ 已验证
DOI
高影响因子
EUROPEAN POLYMER JOURNAL
·
2017
·
IF 3.531
Haohui Huo,Xiaoyan Ma,YeQing Dong,Fengjin Qu
A novel light- and temperature-responsive amphiphilic ABC miktoarm star terpolymer consisting of hydrophilic poly(ethylene glycol) (PEG), light-responsive poly(2-nitrobenzyl methacrylate) (PNBM), and temperature-responsive poly(N-isopropylacrylamide) (PNIPAM) arms, PEG(- b -PNBM)- b -PNIPAM, was synthesized via a combination of atom transfer radical polymerization (ATRP) and click reaction. In aqueous solution, the obtained miktoarm star terpolymer self-assembled into spherical micelles with PNBM cores and hybrid PEG/PNIPAM coronas. When heating above the phase transition temperature of PNIPAM, larger aggregates with mixed PNBM/PNIPAM cores and PEG coronas were formed. Upon UV light irradiation, the initial micelles were disrupted and reassembled into some large micelle complexes. Fluorescence emission measurements showed that Nile red encapsulated in the polymeric micelles could be released by stimuli of UV light or temperature change. More interestingly, the UV triggered release could be strengthened in basic conditions but weakened in acidic conditions. The prepared light- and temperature-responsive polymeric micelles may have great potential in applications such as nanocarriers and biotechnology for controlled drug and bioagent delivery.
研究领域:
材料科学
·
生物医学工程
·
纳米技术
✓ 已验证
DOI
高影响因子
ENERGY & FUELS
·
2022
·
IF 4.654
Difeng Wei,Xuexian Yu,Yingwu Luo,Xiang Gao,Sainan Ma
Silicon monoxide (SiO) is a promising anode material for the next-generation lithium-ion batteries (LIBs) due to its higher capacity than graphite and better cycle life than pure silicon. However, the issues of volume changes, low mass loading, and poor conductivity still exist. In this study, an economic battery manufacturing technique is developed to promote the performance of commercial SiO/C-based batteries. A novel triblock copolymer binder was synthesized and used to relieve the volume changes and improve ion transportation. Copper nanowires were adopted in the anode material to improve electrical conductivity. A high mass loading anode with a laminated conductive structure was fabricated by spraying a layer upon layer. The synthesized SiO/C exhibits a high specific capacity retention of 606 mA h g–1 after 200 cycles at a high areal mass loading of 10.26 mg cm–2. Furthermore, under a current density of 1 C (1255 mA g–1), it delivers a reversible rate capacity of 620 mA h g–1. This novel design paves a new way to fabricate high-performance SiO-based anodes for commercial LIB applications.
研究领域:
材料科学
·
电化学
·
能源存储
✓ 已验证
DOI
高影响因子
JOURNAL OF SOL-GEL SCIENCE AND TECHNOLOGY
·
2016
·Vol. 80
·期 1
·239-248
·
IF 1.473
Cui Yuheng,Kang Xin,Zhang Jie,Zhang Liqun,Yue Dongmei
Abstract Thermoreversible gels were obtained from the well-defined triblock terpolymer poly(n-hexyl isocyanate)-b-polybutadiene-b-poly(n-hexyl isocyanate) (PHIC-b-PB-b-PHIC). PHIC-b-PB-b-PHIC adopted a helical conformation and exhibited florescence in solution. The gels were prepared in both n-heptane and n-octane. The gelation concentration and temperature could be affected by various factors. Hydrogen bonding and intermolecular aggregation were the driving forces to form stable thermoreversible gels. Atomic force microscopy (AFM) showed that the microstructure of the gels consisted of aggregates of fibrous nanoribbons. Because of their thermosensitivity and fluorescence, the thermoreversible gels have potential applications in sensors and temperature-sensitive switches. Graphical Abstract
研究领域:
高分子化学
·
材料科学
·
生物医学工程
✓ 已验证
产品关联
DOI
高影响因子
CARBOHYDRATE POLYMERS
·
2014
·
IF 3.916
Bin Wang,Kefu Chen,Rendang Yang,Fei Yang,Jin Liu
Ethyl cellulose macroinitiator was firstly synthesized by direct acylation of ethyl cellulose with 2-bromopropionyl bromide in a room temperature . And a light-responsive triblock copolymer of ethyl cellulose-g-poly(2-hydroxyethyl methacrylate)-g-poly(spiropyran ether methacrylate) (EC-g-PHEMA-g-PSPMA) was prepared by atom transfer radial polymerization. The amphiphilic structure of the copolymer enabled it to aggregate into spherical micelles in aqueous solution with an average diameter of 100 nm. The micelles exhibited light-responsive performance because of the SPMA monomer . The hydrophobic side chain of PSPMA became hydrophilic under UV light, which decreased the average size of the micelles. Additionally, the diameters of the micelles can be recovered when subsequently irradiated with visible light. The loading and light-triggered release profiles of model drugs were also investigated, and results showed that the release behavior can be controlled by changing the light wavelength.
研究领域:
材料科学
·
药剂学
·
高分子化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
POLYMER
·
2015
·
IF 3.562
Houluo Cong,Lei Li,Sixun Zheng
Poly(ε-caprolactone)- block -polystyrene- block -poly(2,2,2-trifluoroethylacrylate (PCL- b -PS- b -PTFEA) and poly(ε-caprolactone)- block -poly(2,2,2-trifluoroethyl acrylate)- block -polystyrene (PCL- b -PTFEA- b -PS) triblock copolymers were synthesized via the combination of ring-opening polymerization (ROP) and reversible addition-fragmentation chain transfer (RAFT) polymerizations. Both of the triblock copolymers had the similar composition and molecular weights but different sequential structures. These two triblock copolymers were utilized to modulate the nanostructures of epoxy thermosets . It was found that the microdomains in the thermosets were formed through the mechanism of reaction-induced demixing of PS blocks in the presence of the self-assembled PTFEA microdomains. In the thermosets containing PCL- b -PS- b -PTFEA, the spherical and cylindrical microdomains with the core-shell structure were formed. In those containing PCL- b -PTFEA- b -PS, the spherical microdomains were formed but the size of the microdomains displayed a bimodal distribution. The difference in morphology is accounted for by the influence of sequential structures of the copolymers on the reaction-induced demixing behavior of the triblock copolymers in the epoxy thermosets.
研究领域:
材料科学
·
高分子化学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）