溶菌酶蛋白在聚合物防污膜表面的吸附

采用分子动力学模拟方法比较了溶菌酶蛋白在两种典型聚合物防污材料聚乙二醇(PEG)和聚二甲基硅氧烷(PDMS)表面的吸附行为, 在微观上探讨了聚合物膜表面性质对蛋白质吸附的影响. 根据蛋白质与聚合物膜之间的相互作用、能量变化及表面水化层分子的动力学行为, 解释了PEG防污涂层相对于PDMS表面具有更佳防污效果的原因: (1) 相比PDMS涂层, 蛋白质与PEG涂层的结合能量较低, 使其结合更加疏松; (2) 蛋白质吸附到材料表面要克服表面水化层分子引起的能障, PEG表面与水分子之间结合紧密, 结合水难于脱附, 造成蛋白质在其表面的吸附需要克服更高的能量, 不利于蛋白质的吸附.     

溶菌酶蛋白与聚合物防污膜相互作用的分子动力学模拟

采用分子动力学方法研究了溶菌酶蛋白分子(Lysozyme)在2种典型聚合物防污材料(有机硅弹性体聚二甲基硅氧烷PDMS和两性离子类聚磺酸基甜菜碱甲基丙烯酸甲酯SBMA)表面的吸附行为,进一步从微观角度阐释了防污材料的防污机理.通过比较蛋白质与聚合物膜间的作用力和结合能,防污膜表面水化层的动力学性质,以及蛋白质与基底结合位点附近的结构分析表明SBMA有着更优异的防污能力:(1)蛋白质的吸附须要克服两者表面水化层引起的物理障碍和能量势垒,SBMA通过表面氢键、静电作用和笼效应束缚了一层紧密结合的水化层,表面结合水难于脱附,水化层分子的去溶剂化需要克服的能垒高.(2)蛋白质与PDMS的结合能量上更具优势,相比SBMA与蛋白质间的结合更加稳定,不利于蛋白质的脱附.     

聚合物防污材料表面水化层的分子动力学模拟

采用分子动力学方法研究了吸附在聚二甲基硅氧烷(PDMS)和接枝聚磺酸基甜菜碱甲基丙烯酸甲酯(pSBMA)改性后的防污材料膜水化层内的水分子的结构及其动力学性质, 从微观角度解释了聚合物膜具有防污性能的原因. 模拟发现: (1)紧靠聚合物膜形成的水化层是聚合物具有防污性能的关键因素, 该水化层是溶液中的粒子(包括蛋白质分子)与聚合物膜相接触时所要克服的最主要的物理能障; (2)相对PDMS聚合物膜而言, 双离子特性自组装膜(pSBMA)在氢键、静电力的共同作用下, 可以形成空间笼状水分子网结构对水分子具有更强的束缚作用并有效降低水分子的可运动性, 形成的稳定水化层使得pSBMA具有更强的阻碍蛋白质吸附的能力.     

环境友好海洋防污体系的研究进展

海洋污损是海洋资源开发与利用中遇到的一个国际性难题,发展环境友好海洋防污体系是该领域最重要的方向。本文综述了近年来环境友好海洋防污体系的研究进展,并探讨了未来的发展方向。     

含有邻苯二酚基团的材料在抗菌防污领域的研究进展

贻贝是海洋污损生物中最为常见的一类生物,它可以粘附在几乎所有材料的表面,这是由于贻贝能够分泌具有优异粘附性能的贻贝粘附蛋白.贻贝粘附蛋白结构中具有邻苯二酚基团,并已被证明是一种有效的表面改性锚定剂,几乎可以粘附在任何材料表面.本文针对含有邻苯二酚基团的材料,结合近五年的国内外研究报道,介绍了含有邻苯二酚基团材料的制备方...     

疏水蛋白在云母表面的吸附

采用分子动力学模拟方法研究了疏水蛋白(HFBI)在亲水云母表面的吸附过程.通过6组平行的分子动力学模拟得到了2种不同的稳定吸附结构,即通过N端和通过亲水的α螺旋与表面吸附,得到了5种吸附残基.进一步用自适应偏置力方法计算了所有吸附残基与表面的结合自由能.结果表明,残基Lys是吸附过程的关键残基,即当HFBI通过含有Lys残基的α螺旋与云母表面作用时,其吸附构象最稳定.静电作用是吸附过程的主要驱动力.在该吸附结构中,HFBI的疏水面暴露在溶液中,有效降低了云母表面的润湿性.     

溶菌酶分子印迹聚合物膜的制备及其吸附性能

以溶菌酶为模板蛋白质，结合分子印迹技术在硅烷化的基质玻片上制备了溶菌酶分子印迹聚合物膜。实验优化了溶菌酶聚合物膜的印迹体系，考察了溶菌酶分子印迹聚合物膜的吸附平衡时间、最大吸附量、特异识别能力、重复使用性以及对实际样品中溶菌酶的分离情况。结果表明，在最优条件下，制备的分子印迹聚合物膜对溶菌酶具有特异吸附能力，印迹因子为3.0，吸附平衡时间为5 min，吸附行为符合Langmuir吸附模型，理论最大吸附量为42.5 mg/g，实际样品中的吸附量为30 mg/g。且此印迹聚合物膜在重复使用5次后，最大吸附量仅下降了5%，具有良好的重复使用性。该方法为复杂生物样品中目标蛋白质的分离富集提供了一种快速、高效的手段。     

超疏水性聚二甲基硅氧烷膜的制备及其表面吸附性研究

采用简单的激光刻蚀方法制备了具有类“菜花”状多级结构的粗糙聚二甲基硅氧烷(PDMS)膜, 并用CCD与高敏感性微电力学天平观察和测量PDMS表面对水的吸附情况. 结果表明, 该膜表面具有超疏水性, 同时对水滴具有超低的吸附力. 还对其表面特殊多级结构产生的机理进行了分析, 并探讨了在化学组成和表面结构对超疏水性以及吸附性产生的影响.     

PDMS微芯片吸附牛血清白蛋白的研究

材料表面的物理和化学性质对蛋白质的吸附具有很大的影响[1].对蛋白质吸附的研究是研制生物传感器、生物芯片和生物材料的基础.     

抗蛋白吸附PLLA-MPEG微绒毛膜的制备

在左旋聚乳酸(PLLA)膜上采用朗格缪尔-布洛杰特(LB)技术、浇铸和化学接枝的方法制备了左旋聚乳酸-甲基端聚乙二醇(PLLA-MPEG)共聚物微绒毛膜。通过原子力显微镜(AFM)和水接触角测量等方法考察了制备方法及条件对绒毛层性能的影响,对绒毛层的亲水性、稳定性和抗蛋白吸附性能进行了对比分析。结果表明:通过这3种方法均能获得较亲水的抗蛋白吸附表面。PLLA-MPEG单分子LB微绒毛必须在热水中处理后才能牢固地黏附于PLLA膜上;浇铸的PLLA-MPEG成膜性好,但遇水易脱落,稳定性差;紫外光催化接枝的微绒毛制备简便、铆接牢固,可用于医疗器械或生物埋置材料的表面修饰。     

双分布聚乙二醇接枝纳米二氧化硅的高效可控制备

在混合溶剂中通过"grafting to"的方法将2种分子量不同的聚乙二醇单甲醚(MPEG M_w=750,4000)接枝到氨基修饰的St?ber法二氧化硅(SiO_2-NH_2)表面,制备双分布纳米接枝复合物.采用二步法,先将带环氧端基的低分子量聚乙二醇单甲醚(MPEG-EO)与SiO_2-NH_2在甲苯溶剂中充分反应后,与高分子量的MPEG-EO在甲苯和正癸烷的混合溶剂中使用相同的反应条件和后处理方法,能便捷制备出具有双分布接枝的纳米复合物.在接枝反应体系中,分子链的链段尺寸和接枝密度之间存在着密切关系.一定的范围内,接枝密度随链段尺寸减小而增大.通过改变混合溶剂比例来调控接枝链段的尺寸,可以很好控制聚合物的接枝密度.在双分布接枝的纳米复合物中,低分子量的接枝密度为0.85 chains/nm~2,高分子量的接枝密度能达到0.40 chains/nm~2,体现出了简单、高效、可控的特点,与聚环氧乙烷(PEO)共混后分散良好,对于制备出均匀分散的纳米复合材料起到了一定的指导作用.     

Ionic transport studies on (PEO)6:NaPO3 polymer electrolyte plasticized with PEG400

Conduction characteristics of the poly(ethylene oxide) based new polymer electrolyte (PEO)₆:NaPO₃, plasticized with poly(ethylene glycol) are investigated. Free standing flexible electrolyte films of composition (PEO)₆:NaPO₃ + x wt.% PEG₄₀₀ (30 ? x ? 70) are prepared by solution casting method. A combination of X-ray diffraction (XRD), optical microscopy and differential scanning calorimetry (DSC) studies have indicated enhancement in the amorphous phase of polymer due to the addition of plasticizer. Further, a reduction in the glass transition temperature observed from the DSC result has inferred increase in the flexibility of the polymer chains. The cationic transport number (t_Na⁺) of 0.42 determined through combined ac-dc technique has confirmed ionic nature of conducting species. Ionic conductivity studies are carried out as a function of composition and temperature using complex impedance spectroscopy. The electrolyte with maximum PEG₄₀₀ content has exhibited an enhancement in the conductivity of about two orders of magnitude compared to the host polymer electrolyte. The complex impedance data is analyzed in conductivity, permittivity and electric modulus formalism in order to throw light on transport mechanism. A solid state electrochemical cell based on the above polymer electrolyte with a configuration Na|SPE|(I₂ + acetylene black + PEO) has exhibited an open circuit voltage of 2.94 V. The discharge characteristics are found to be satisfactory as a laboratory cell.     

New architectures of poly(ethylene glycol) and poly(methylthiirane) in block copolymers

Two synthetic ways were experimented to prepare new architectures of block copolymers made of poly(ethylene glycol) (PEG) and poly(methylthiirane). The coupling of both blocks conveniently end-capped as well as anionic polymerization of methylthiirane initiated by PEG-thiols gave readily the copolymers. Their characterization by ¹H NMR, SEC and IR confirmed the expected structures.     

The Synthesis of Poly(ethylene oxide)-Block-Polybutylacrylate

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聚甲基丙烯酸甲酯/星形聚乙二醇半互穿聚合物网络的形状记忆性能和分子机理

采用非共价复合方法,设计并合成了具有星形结构的聚甲基丙烯酸甲酯/星形聚乙二醇半互穿聚合物网络(PMMA/SPEG)和聚甲基丙烯酸甲酯/线性聚乙二醇半互穿聚合物网络(PMMA/LPEG).研究了PEG分子量对PMMA/SPEG和PMMA/LPEG的热性能、机械性能、动态机械性能和形状记忆性能的影响.结果表明,与PMMA/LPEG相比,星形结构的嵌入显著提高了PMMA/SPEG复合物的机械性能、形状回复率和回复速度.采用Edwards管道模型理论对其形状记忆效应的分子机理进行了阐释,利用材料的应力松弛特性对机理分析进行了验证.     

SYNTHESIS OF NOVEL BLOCK COPOLYMERS OF POLY(3-HYDROXYBUTYRIC ACID)WITH POLY(ETHYLENE GLYCOL)THROUGH ANIONIC POLYMERISATION

A novel kind of copolymer with ABA-type block structure was synthesized by anionic ring-openingpolymerization of β-butyrolactone (β-BL) in the presence of a PEG-based dicarboxylates as macroinitiators which wereprepared by the esterification of aliphatic cyclic anhydride and poly(ethylene glycol) (PEG) oligomers (M_n=2000, 4000 and6000) and conversion of potassium dicarboxylates. The resultant copolymers as well as the intermediates were characterizedby IR,~1H-NMR and GPC.     

基于聚乙二醇结构调控高分子量聚乳酸立构复合体系的结晶行为

设计合成了梳形聚(聚乙二醇甲醚丙烯酸酯)(PPEGA)及其与聚乙二醇(PEG)的嵌段共聚物(PEG-b-PPEGA).通过与高分子量左旋聚乳酸(PLLA)和右旋聚乳酸(PDLA)共混探究了PEG不同的结构对PLA立构复合体系(sc-PLA)结晶的影响.结果 表明线形PEGA和PEG能与sc-PLA完全相容,两者均能促进...     

Preparation, characterization and biocompatibility of poly(ethylene glycol)-poly(n-butyl cyanoacrylate) nanocapsules with oil core via miniemulsion polymerization

A new type of nanocapsules with an oil core, coated by poly(ethylene glycol) (PEG) was designed. The loading efficiency and the biocompatibility of the polymeric nanocapsules were evaluated when it was used as a carrier for hydrophobic agent paclitaxel. The nanocapsules were synthesized through miniemulsion polymerization of butylcyanoacrylate (BCA) with PEG as initiator. The particle size and zeta potential of nanocapsules were influenced by the PEG content in the polymerization system. Fourier transform infrared (FTIR) spectra and ¹H NMR demonstrated the chemical coupling between PEG and poly(butylcyanoacrylate) (PBCA). Thermal characteristics of the copolymer were investigated by differential scanning calorimetry (DSC). The encapsulation efficiency increased concurrently with the increase of the PEG content in the system. The hemolytic assay and the cytotoxicity measurement showed that the PEG coating could significantly reduce the hemolytic potential and cytotoxicity of the nanocapsules. The results showed that the PEG-PBCA nanocapsules could be an effective carrier for hydrophobic agents.     

Study on Self-assembly of Poly(ethylene glycol)- block-poly(γ-benzyl L -glutamate)-graft-poly(ethylene glycol) Copolymer and Poly(γ-benzyl L -glutamate)- block-poly(ethylene glycol) Copolymer in Ethanol

Poly(ethylene glycol)-block-poly(γ-benzyl L-glutamate)-graft-poly(ethylene glycol) (PEG-b-PBLG-g-PEG) copolymer was synthesized by the ester exchange reaction of poly(γ-benzyl L-glutamate)-block-poly(ethylene glycol) (PBLG-block-PEG) copolymer with PEG chain, and PBLG-block-PEG copolymer was prepared by a standard N-carboxyl-γ-benzyl-L-glutamate anhydride (NCA) method. Nuclear magnetic resonance (NMR) spectroscopy was used to confirm the components of PBLG-block-PEG and PEG-b-PBLG-g-PEG. The self-association behaviors of PBLG-block-PEG and PEG-b-PBLG-g-PEG in ethanol were investigated by transmission electron microscopy (TEM), dynamic laser scattering (DLS), and viscometry. The experimental results revealed that the different molecular structures could exert marked effects on the self-assembly behaviors of PBLG-block-PEG and PEG-b-PBLG-g-PEG in ethanol. PBLG-block-PEG and PEG-b-PBLG-g-PEG could self-assemble to form polymeric micelles with a core-shell structure in the shapes of plump spherical and regular rice-like, respectively. Effects of the introduction of PBLG homopolymer on the average particle diameter of the micelles of PBLG-block-PEG and PEG-b-PBLG-g-PEG and influence of testing temperature on the critical micelle concentration of different copolymers were studied.