α-淀粉酶在阴离子化PET表面的自组装膜及其AFM研究

采用分子沉积技术制备了α-淀粉酶的自组装膜，并用AFM研究了在不同的pH值溶液和不同电荷密度基底上得到的自组装膜。结果表明：pH值从6.0变到4.0，形状变得尖细，膜中陷点多；基底的电荷密度增大时，酶分子的外观形状较细，膜中缺陷点少；α-淀粉酶自组装膜的厚度保持约5～10nm。     

脂肪酶在负离子化PET表面的单分子层自组装膜研究

研究了脂肪酶分子在表面负离子化聚对苯二甲酸乙二醇酯（PET）薄膜表面的分子自组装,由AFM和FTIR－ATR等方法研究脂肪酶单分子层膜的表面结构;活力测定表明：脂肪酶／PET自组装单分子层膜的酶活力表现率约为2.0左右。     

HRP/PET自组装膜及其在光度分析中的应用

利用静电自组装技术在阴离子化的PET表面组装了单分子层的HRP酶膜,通过AFM对膜表面形貌进行了分析.由于HRP的沉积,PET薄膜在组装HRP前后,表面形貌发生了较大的变化,表面粗糙度(Rms)由0.645 nh增加到2.580 nm,表面酶颗粒高度为3.3 nm,与HRP的XRD数据(4.028 nm×6.746 nm×11.711)基本相符.制备的酶自组装膜在4℃的低温条件下密封保存.该酶膜在最初的一个星期内酶活性下降较快,之后酶活性则基本保持不变,150天后仍能保持最初时的80%以上的活性;而在常温下,酶膜很快失去活性.表明自组装HRP/PET酶膜在低温下具有很好的保存稳定性.以微量比色皿为反应容器,考察了酶膜与H2O2的显色反应动力学,该反应的表观米氏常数Kapp m=3.2×10-5 mol/L(相对于H2O2底物),显色反应在5 min内完成.在所考查的H2O2浓度浓度区间内(8.8×10-6～8.8×10-5mol/L),酶膜所催化的显色反应产物的吸光度与其浓度之间存在良好的线性关系,对样品中H2O2测定的回收率为96.5%～101.1%.     

HRP/PET自组装酶膜及其在光度分析中的应用

利用静电自组装技术在阴离子化的PET表面组装了单分子层的HRP酶膜 ,通过AFM对膜表面形貌进行了分析。制备的酶自组装膜在4℃的低温条件下 ,密封保存150d后 ,酶活性仍保留80 %以上。以微量比色皿为反应容器 ,考察了酶膜与H2O2 的显色反应动力学 ,该反应的表观米氏常数 Kmapp=3.2×10-5mol·L-1(相对于H2O2 底物) ,显色反应在5min内完成 ,对样品中H2O2 测定的回收率为96.5%～101.1 %。     

辣根过氧化物酶自组装多层膜结构形貌与活性的研究

用分子沉积自组装作制备了阳离子化和阴离子化的辣根过氧化物酶自组装膜；并用原子力显微镜（AFM）研究了不同离子化辣根过氧化物酶单层及多层自组装膜的形貌结构与自组装膜的活性变化关系。结果表明：阴离子化的辣根过氧化物酶自组装膜的表面形貌比较粗糙，均方根粗糙度（RMS）及酶分子粒径较大，且组装膜的活性比较大。     

自组装杂化离子通道膜的构筑及阳离子传输机制

以3-异氰酸丙基三乙氧基硅烷和对甲氧基苯胺为原料合成了一种可以自组装形成有机-无机杂化材料的化合物--3-(脲基-4-甲氧基苯基)丙基三乙氧基硅烷. 采用FT-IR, ¹H NMR, DSC 和XRD 分析方法对该化合物的结构以及结晶性进行了表征. 将该化合物与聚乙烯醇(PVA)共混, 利用化合物的自组装性质构筑结构均一且致密无孔的离子通道杂化膜, 通过自制的膜运输实验装置测定膜对阳离子的传输性能并提出了相应的传输机制. SEM 照片显示, 自组装杂化膜致密无缺陷, 膜厚度为8 μm. 选择5 种阳离子进行运输实验测试, 结果表明, 自组装杂化离子通道膜对一价的碱金属离子Li⁺, Na⁺和K⁺有很好的传输功能, 这要归功于杂化材料中甲氧基苯基与碱金属阳离子形成的阳离子-π相互作用力. 碱金属阳离子在膜中的扩散过程可由溶解-扩散机制来解释, 结果显示, Li⁺, Na⁺和K⁺在杂化膜中传输的渗透率大小为: P_Na⁺ > P_K⁺ > P_Li⁺ , 说明本研究中的的自组装杂化离子通道膜对Na⁺有优先选择性. 杂化离子通道膜对二价的Ca²⁺和Mg²⁺没有传输作用, 此结果给一二价阳离子的分离带来很好的研究思路.     

电流滴定法对自组装膜表面酸碱性的研究

近年来 ,有序分子自组装体系在基础研究和应用领域均得到了较大的发展 .选择末端可以解离的自组装分子而制成的自组装膜 ,可以方便地通过调节底液的 p H值来控制膜体系的荷电状况 [1] ,这在利用静电作用吸附蛋白质 [2 ] 、多肽 [3] 、 DNA[4 ] 、聚电解质 [5] 、金属离子及其它物种 [6] 等方面具有重要作用 .精确测定表面解离常数 (即表面 p Ka)和控制自组装膜表面的荷电状况 ,无疑在理论研究和实践中均占有重要地位 .目前 ,一些方法如接触角滴定 [7] 、微分界面电容 [8] 、电流滴定法 [9,10 ] 以及 AFM的力曲线滴定 [11,12 ]被用于表面…     

超支化聚负离子/超支化聚正离子自组装膜的制备及反应

自1991年以来,静电吸附自组装已发展成为制备具有特定纳米微结构聚电介质多层超薄膜的有效技术。近年来,由于树枝状聚合物和超支化聚合物独特的物理化学性质,文献中已将它们与线性聚电解质一起用于静电吸附自组装过程,但完全基于超支化聚合物分子间的自组装过程还鲜见报道,超支化聚合物所具有的大量末端和内部（如叔胺基）官能团,不仅可以用于调节自组装行为及组装膜的表面形貌,     

OTS自组装单分子膜在玻璃表面形成过程的AFM研究

运用原子力显微镜研究了十八烷工碱氯硅烷在玻璃表面自组装形成单分子膜的过程。通过对样品表面的显微图像,表面平均粗糙度及前进接触角的测量分析,揭示了自组装单分子膜在玻璃表面的生长规律,并探索反应初期玻璃表面的吸附特点。     

PTT/PET共混体系晶体形态与结晶性能的研究

用差示扫描量热仪(DSC)、广角X射线衍射(WAXD)和正交偏光显微镜研究了聚对苯二甲酸丙二酯(PTT)和聚对苯二甲酸乙二酯(PET)共混体系的晶体形态与结晶性能.结果表明,共混体系结晶性能与PTT的含量有关.PET的加入,使共混体系的球晶尺寸减小.球晶完善性降低.当PTT含量为40wt%～60wt%时,共混物分别出现了双重熔融峰和双重结晶峰.双重熔融峰是加热过程中熔融重结晶造成的,双重结晶峰说明不完善的晶体产生的次级结晶.     

LBL自组装技术及自组装生物功能膜结构

主要介绍近几年发展的用于生物大分子自组装功能膜的三种逐层（LBL）自组装技术与制备方法,酰胺化反应自组装技术、生物分子的特异识别自组装技术、分子沉积自组装技术;同时总结了自组装功能膜的结构、特性的表征方法,主要有AFM、TEM、循环伏安法、石英晶体微天平（QCM）技术、UV/VIS、XPS方法等。     

Functional Transformations on the Surface of Poly(ethylene terephthalate) Films under Exposure to Accelerated Electrons

The effect of the electron-beam treatment of poly(ethylene terephthalate) (PETP) films in an air atmosphere on the functional chemical composition of their surface and on the optical properties in the UV region was studied. The mutual functional transformations of surface sites (carbonyl, methyl, and hydroxyl groups) by the action of fast electrons were analyzed as functions of the absorbed dose over the range 25–500 kGy using the adsorption of acid–base indicators with the pK_a values ranging from –5 to 15. Correlation between the absorbed dose, the concentration of certain functional groups (centers with pK_a 5.0 (–CH₃) and 0.8 (–CH₂OH)), the hydrophilicity of films, and the transparency in the UV region of the spectrum was established. The transparency was found to exhibit a pronounced minimum at an absorbed dose of 150–200 kGy. A comparative analysis of PETP surfaces differing by the absence or presence of kaolin (0.1%) as an oxide material additive was performed. Differences in the pK_a distribution of adsorption sites were found, and their dependence on the absorbed dose was studied.     

Mechanical Properties of the Nanometer Scale Precrystalline Order of a Poly(ethylene terephthalate)/Poly(ethylene naphthalate) Blend

Summary: Nanometer scale morphological order of macroscopically amorphous polyesters, obtained from the melt at moderate cooling rates, was observed in the past. The effect of such order on mechanical properties of a PET/PEN blend, evaluated by AFM nanoindentations, is reported in this study. Results show that nanoindentations conducted at relatively high load, with penetration depths of the order of 100 nm, confirm the information obtained from mechanical tests at micrometer scale, i.e., microhardness. On the other hand, true nanometer scale indentations (<40 nm) are seen to discriminate between the mechanical properties of the nanophases formed during solidification.

Statistical distribution of elastic moduli observed after 60 nanoindentations performed at 1 µN on each sample solidified at the cooling rates reported in the legend.     

Low-Frequency Glow Discharge Treatment of Poly(ethylene terephthalate) Films

The alteration of surface characteristics of the PET-E poly(ethylene terephthalate) film by treatment in the cathode fall of an ac (50 Hz) glow-discharge plasma was studied. The plasma-assisted modification leads to surface hydrophilization which is retained for a long period of time. It was found that the discharge treatment induced a negative charge in the polymer surface layer. The charge density created under different treatment conditions was correlated with the contact angle. The thermally stimulated relaxation and depolarization measurements on the original and the modified film showed that charge buildup in the film during the discharge treatment was due to trapping of injected electrons. From the experimental data, it was inferred that the charge states emerged play the determining role in enhancing the surface energy of modified PET films.     

自组装成膜技术制备TiO2薄膜的XPS研究

采用自组装成膜技术制备里TiO2薄膜,应用X射线光电子能谱研究自组装膜及其氧化膜和淀积的TiO2薄膜，结果表明，硅烷偶联剂成功地组装在玻璃基片上，足够长时间的氧化对使端基（-SH）完全氧化为磺酸基，淀积在基片上的TiO2膜牢固性好，平均膜厚在10nm．淀积膜中的钛可能有几种不同的氧化态，不同的酸度影响TiO2的淀积效果     

乙烯吡咯烷酮对PET薄膜的表面接枝改性

利用低温等离子体和UV诱导技术,制备具有较高生物相容性和亲水性的聚对苯二甲酸乙二醇酯(PET)-聚乙烯吡咯烷酮(PNVP)复合膜。利用衰减全反射傅里叶红外光谱(ATR-FTIR)、X射线光电子能谱(XPS)、原子力显微镜(AFM)对PET-PNVP复合膜表面的结构形态进行了系统表征,对影响接枝度的因素如引发剂浓度、UV辐射时间、单体浓度也做了系统分析。润湿性分析结果表明,接枝PNVP的PET膜表面亲水性得到了有效改善。体外血液相容性实验表明PET-PNVP复合膜具有较好的血液相容性。噻唑蓝比色法(MTT法)细胞毒性实验表明,PETPNVP复合膜没有细胞毒性。     

胶体颗粒在聚电解质多层膜表面的可控组装

利用原子力显微镜和扫描电子显微镜研究了磺化聚苯乙烯胶体颗粒在由聚二甲基二烯丙基氯化铵和聚苯乙烯磺酸钠层状自组装而成的多层膜表面的组装.该组装受表面性质影响,通过对多层膜的最外层的组装条件或利用盐溶液对多层膜进行后处理可以控制胶体颗粒在膜表面的组装密度.     

Control of Induced Chirality in Optically Active Poly(N‐propargylcarbamate) Films by Solvent Vapor

Chiral polyethyne derivatives with lyotropic liquid‐crystalline properties are found to be able to self‐assemble, forming two chiral organizations with opposite handedness in solid thin films by selection of the casting solvent and its concentration. After the film preparation, chiral organization could also be induced by simple exposure to an appropriate organic solvent's vapor for several minutes without thermal treatment. Furthermore, irreversible inversion of the handedness of the chiral organization in the film could be achieved by exposure to solvent vapor.

     

Interaction between model poly(ethylene terephthalate) thin films and weakly ionised oxygen plasma

Model films of poly(ethylene terephthalate) were treated by oxygen plasma in order to quantify the etching rate and estimate the contribution of charged and neutral particles to the reaction probability. Model films with a thickness of 50 nm were deposited on a quartz crystal of a microbalance (QCM) by spin‐coating technique. The samples were exposed to oxygen plasma with the positive ion density of 4 × 10¹⁵ m^?3 and neutral oxygen atom density of 6 × 10²¹ m^?3. The etching rate was determined from the QCM signal and was 4.7 nm s^?1. The etching was found rather inhomogeneous as the atomic force microscopic images showed an increase of the surface roughness as a result of plasma treatment. The model films were completely removed from the surface of the quartz crystals in about 12 s. Knowing the etching rate and the flux of oxygen atoms to the surface allowed for calculation of the reaction probability which was found to be rather low at the value of 1.6 × 10^?4. Copyright © 2011 John Wiley & Sons, Ltd.