检索结果-南通市图书馆

A Facile and Environment-friendly Method for Fabrication of polymer brush

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of polymer Science 2017年第7期35卷 857-865页

作者： Xiao-min Kang Wan-hao Cai Hong-gang Gu Shi-yuan Liu 崔树勋 Key Laboratory of Advanced Technologies of Materiais Ministry of Education Southwest Jiaotong University Chengdu 610031 China State Key Laboratory of Digital Manufacturing Equipment and Technology Huazhong University of Science and Technology Wuhan 430074 China

A novel environment-friendly system is proposed to fabricate polymer brush, which has the advantages including non-toxic and inexpensive initiator （eosin Y）, visible-light exposure （λ = 515 nm）, water medium and ambient environment. The experimental results from UV-Vis spectroscopy, AFM-based single molecule force spectroscopy （SMFS） and other measurements indicate that a polymer brush with a living nature is fabricated via free radical polymerization. This polymer brush may find applications in coatings, bio-interfaces and so forth.

关键词： polymer brush Green chemistry Free radical polymerization Living polymerization

How Does a polymer brush Repel Proteins?

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of polymer Science 2014年第11期32卷 1575-1580页

作者：吴奇 Department of Chemistry The Chinese University of Hong KongShatinN.T.Hong KongChina The Open Laboratory of Bond Selective Chemistry Department of Chemical PhysicsUniversity of Science and Technology of China

The captioned question has been addressed by the steric effect; namely, the adsorption of proteins on a surface grafted with linear polymer chains decreases monotonically as the grafting density increases. However, there is no quantitative and satisfactory explanation why the adsorption starts to increase when the grafting density is sufficiently high and why polyethylene glycol（PEG） still remains as one of the best polymers to repel proteins. After considering each grafted chain as a molecular spring confined inside a ＂tube＂ made of its surrounding grafted chains, we estimated how its free energy depends on the grafting density and chain length, and calculated its thermal energy-agitated chain conformation fluctuation, enabling us to predict an adsorption minimum at a proper grafting density, which agrees well with previous experimental results. We propose that it is such a chain fluctuation that slows down the adsorption kinetically.

关键词： polymer brush Protein adsorption Antifouling.

Friction between Strongly Compressed polymer brushes

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of polymer Science 2024年第9期42卷 1368-1374,I0008页

作者： Qi Liao Institute of Chemistry Chinese Academy of SciencesBejing 100190China

We present the results of molecular dynamics simulations of steady shear between a pair of neutral polymer brushes,as well as a pair of charged polymer brushes in the strongly compressed *** results of the molecular dynamic simulations of neutral and polyelectrolyte brushes in implicit solvent including normal forces,shear forces,viscosities and friction coefficients as a function of separation between brushes,are presented in the *** comparison of the simulation results of neutral and charged brushes shows that the charged brushes is in the quasi-neutral regime,and the dependence of viscosity on the separation distance show the similar power law of neutral *** simulation results confirm that the implicit solvent simulations of polyelectrolyte brushes that ignore hydrodynamics interaction are in agreement with the scaling predictions qualitatively because of screening of hydrodynamic interaction and long-range electrostatic interactions on the correlation length *** of neutral and charged brushes show the lubrication properties that the friction coefficient decreases with the separation decreases at enough large ***,a maximum of friction coefficients is observed for polyelectrolyte brushes,which is in contrast to the neutral brushes with monotonical dependence.

关键词： polymer brush Frictions coefficient Polyelectrolyte Lubrication

Simultaneous Bulk-and Surface-initiated Living polymerization Studied with a Heterogeneous Stochastic Reaction Model

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of polymer Science 2024年第3期42卷 364-372,I0008页

作者： Jia-Shu Ma Zhi-Ning Huang Jia-Hao Li Bang-Ping Jiang Yan-Da Liao Shi-Chen Ji Xing-Can Shen State Key Laboratory for Chemistry and Molecular Engineering of Medicinal Resources Key Laboratory for Chemistry and Molecular Engineering of Medicinal Resources(Ministry of Education of China)School of Chemistry and Pharmaceutical SciencesGuangxi Normal UniversityGuilin 541004China School of Computer Science and Engineering&School of Software Guangxi Normal UniversityGuilin 541004China

To better characterize the properties of surface-initiated polymers, simultaneous bulk-and surface-initiated polymerizations are usually carried out by assuming that the properties of the surface-initiated polymers resemble those of the bulk-initiated polymers. Through a Monte Carlo simulation using a heterogeneous stochastic reaction model, it was discovered that the bulk-initiated polymers exhibit a higher molecular weight and a lower dispersity than the corresponding surface-initiated polymers, which indicates that the equivalent assumption is invalid. Furthermore, the molecular weight distributions of the two types of polymers are also different, suggesting different polymerization mechanisms. The results can be simply explained by the heterogeneous distributions of reactants in the system. This study is helpful to better understand surface-initiated polymerization.

关键词： Surface-initiated polymerization polymer brush Stochastic reaction model Heterogeneous polymerization Simultaneous polymerization

在线全文

学校读者我要写书评

暂无评论

应用于高效雾气收集的润滑微沟槽锥

Science China Materials 2024年第5期67卷 1574-1580页

作者：杨二鑫马臣西罗玉琼刘岚郑爽爽姚晰鞠婕 Key Lab for Special Functional Materials of Ministry of Education School of MaterialsHenan UniversityKaifeng475004China

液滴在不对称一维表面的定向输送具有广泛应用,包括雾气收集、油水分离、海水淡化及传感等.液滴所受的驱动力和阻力共同作用决定液滴的运动性能,为提高液滴的运动性能,常见的策略是通过在运动方向引入各种不对称结构以增加驱动力,或者... 详细信息

液滴在不对称一维表面的定向输送具有广泛应用,包括雾气收集、油水分离、海水淡化及传感等.液滴所受的驱动力和阻力共同作用决定液滴的运动性能,为提高液滴的运动性能,常见的策略是通过在运动方向引入各种不对称结构以增加驱动力,或者构建光滑表面以减少阻力.然而,到目前为止将增强驱动力和降低阻力同时整合到一个体系中的策略仍未见报道,这主要是由于传统的液体填充润滑表面所需的润滑油很难在物理或化学不对称的表面上稳定存在.本研究中,我们提出在具有微沟槽结构的锥表面接枝柔性聚合物分子刷,即通过协同表面结构和化学修饰来增大液滴在锥结构表面拉普拉斯驱动力并减小粘滞阻力.结果表明,与仅具有微沟槽结构的锥和仅具有聚合物分子刷的光滑锥相比,润滑微沟槽锥可显著提高液滴的运动性能,本研究为开发高效液滴运输智能表面提供了新思路.

关键词： cone structure micro-grooves polymer brush fog harvesting

Structures and Surface States of polymer brushes in Good Solvents:Effects of Surface Interactions

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of polymer Science 2018年第9期36卷 1047-1054页

作者： Yi-Xin Liu Hong-Dong Zhang State Key Laboratory of Molecular Engineering of polymers Department of Macromolecular Science Fudan University

The influence of the surface interaction on the mesoscopic structure of grafted polymers in good solvents has been examined. At high surface coverage, tethered polymers are in the brush state and the parabolic segment density profile is confirmed by self-consistent field theory （SCFT） calculations. It is found that this is a universal behavior for a whole range of surface interactions from complete repulsion to strong attraction. More interestingly, finite surface repulsion may lead to the maximum in the proximal layer of its segment density profile, which is significantly different from both the depletion layer of pure repulsion and the adsorbing layer of attraction. In addition to the brush state on both repulsive and attractive surfaces, three additional surface states were identified by analyzing the scaling behavior of the layer thickness of polymer brushes： the mushroom state on repulsive substrates, the dilute and the semidilute surface states on attractive substrates.

关键词： Self-consistent field theory Scaling theory polymer thin film polymer brush

Surface-floating gold nanorod super-aggregates with macroscopic uniformity

在线全文

学校读者我要写书评

暂无评论

Nano Research 2018年第5期11卷 2379-2391页

作者： Abdul R. Ferhan Youju Huang Anirban Dandapat Dong-Hwan Kim School of Chemical and Biomedical Engineering Nanyang Technological University 62 Nonyang Drive 6374S7 Singapore School of Chemical Engineering Sungkyunkwan University Gyeonggi-do 16419 Republic of Korea

We present a simple method for obtaining high-density two- and three- dimensional assemblies of gold nanorods （AuNRs） on polymer brush, referred to as ＂surface-floating super-aggregates＂, with uniform distribution spanning macroscopic distances. This was achieved via the single-step immersion of a poly（oligo ethylene glycol methacrylate） brush-containing substrate in a AuNR solution without any form of functionalization. Owing to extensive macroscale plasmonic coupling, we observed for the first time the gradual evolution of a unique sharp peak in addition to the transverse and longitudinal peaks, in this case, in the near-infrared （NIR） region. We also highlight the dynamic nature of these surface-floating super-aggregates, in which the AuNRs spread out when immersed in solution and collapse when dried to facilitate the access of probe molecules for biosensing applications. As a proof of concept, the surface-floating super-aggregates were used for surface-enhanced Raman spectroscopy, with which we detected rhodamine 6G at as low as sub-femtomolar concentrations. Owing to the excellent large-area uniform coverage and extreme simplicity of the fabrication method, such AuNR assemblies can easily be mass-produced and incorporated into cheap biosensors suitable for consumer use in the near future.

关键词： nanoparticle polymer brush nanocomposites surface-enhanced Raman spectroscopy (SERS)

Collapse of Four-Arm Stars Polyelectrolyte brushes Under An Electric Field in the Presence of Trivalent Salt Coions

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Chemical Physics 2021年第3期34卷 356-364,I0009-I0012,I0048页

作者： Yu Ji Shao-yun Wang Chao-hui Tong Department of Physics School of Physical Science and TechnologyNingbo UniversityNingbo 315211China

Langevin dynamics simulations were conducted to study the collapse of grafted partially charged 4-arm star chains onto the oppositely charged grafting electrode in the presence of trivalent salt *** results reveal that the average charge fraction of the grafted star chains and the salt concentration play critical roles in the competitive adsorption of charged monomers and trivalent salt coions onto the oppositely charged *** grafted star chains with relatively high charge fraction,charged monomers are the dominant species collapsing on the oppositely charged electrode with the emergence of charge reversal on the grafting *** a low charge fraction such that the total amount of charges on a grafted star molecule is comparable to that of a trivalent salt coion,trivalent salt coions absorb more strongly onto the electrode than grafted stars even at very low salt *** is found that at relatively low charge fraction of star chains,the addition of trivalent salt coions does not lead to charge overcompensation of the surface charges on the grafting *** stretching of star brushes under an electric field in the presence of trivalent salt coions was also briefly investigated.

关键词： polymer brush Charged polymer Electric field Adsorption Molecular dynamics Electrostatics Multivalent ion

Templated synthesis of patterned gold nanoparticle assemblies for highly sensitive and reliable SERS substrates

在线全文

学校读者我要写书评

暂无评论

Nano Research 2023年第4期16卷 5056-5064页

作者： Jianping Peng Peijiang Liu Yutong Chen Zi-Hao Guo Yanhui Liu Kan Yue South China Advanced Institute for Soft Matter Science and Technology School of Emergent Soft MatterSouth China University of TechnologyGuangzhou 510640China National Key Laboratory for Reliability Physics and Its Application Technology of Electrical Component the 5th Electronics Research Institute of the Ministry of Information IndustryGuangzhou 510610China College of Textiles&Clothing Laboratory of New Fiber Materials and Modern TextileState Key laboratory of Bio-Fibers and Eco-TextilesQingdao UniversityQingdao 266000China

Formation of plasmonic structure in closely packed assemblies of metallic nanoparticles(NPs)is essential for various applications in sensing,renewable energy,authentication,catalysis,and ***,a surface-enhanced Raman scattering(SERS)substrate is fabricated for trace detection with ultrahigh sensitivity and *** SERS substrate is constructed from a simple yet robust strategy through in situ growth patterned assemblies of Au NPs based on a polymer brush templated synthesis *** from the dense and uniform distribution of Au NPs,the resulting Au plasmonic nanostructure demonstrates a very strong SERS effect,while the outer polymer brush could restrict the excessive growth of Au NPs and the patterned design could achieve uniform distribution of Au *** results,an ultra-low limit of detection(LOD)of 10^(−15)M,which has never been successfully detected in other work,is determined for 4-acetamidothiophenol(4-AMTP)molecules and the Raman signals in the random region show good signal homogeneity with a low relative standard deviation(RSD)of 7.2%,indicating great sensitivity and reliability as a SERS *** LOD values of such Au plasmonic nanostructures for methylene blue,thiram,and R6G molecules can also reach as low as 10^(−10)M,further indicating that the substrate has a wide range of applicability for SERS *** the help of finite difference time domain simulations(FDTD)calculation,the electric field distribution of the Au plasmonic nanostructures is simulated,which quantitatively matches the experimental ***,the Au plasmonic nanostructures show good shelf stability for at least 10 months of storage in an ambient environment,indicating potentials for practical applications.

关键词： templated synthesis patterned Au nanostructures surface-enhanced Raman scattering polymer brush plasmonic nanostructures