新型芳香胺－邻醌聚合物的合成及其作为纳料固定化酶载体的研究

以碘酸盐为氧化剂,通过氧化－迈克尔加成反应,由邻苯二酚和4,4'-亚甲基 苯胺合成了一种新的功能聚合物,芳香胺－邻醌聚合物。这种聚合物表面由分布均 匀的纳料颗粒和孔穴构成。由于这种聚合物分子含有疏水骨架、羰基和胺基的有序 分布,以及独特的纳料微观颗粒和孔穴结构,使其成为吸附法固定化酶的良好载 体。     

烷基硫酸钠中碳链长度分布对MMA种子乳液聚合粒径分布影响的研究

氯磺酸法合成了C8－10、C12和C14－16烷基硫酸钠，精制后表征了碳链分布组成，在C12为30％－80％范围内研究了烷基硫酸钠中高碳同系物和低碳同系物的比例对甲基丙烯酸甲酯种子乳液聚合生成的聚合物粒径大小和分布的影响，并讨论了成核模式。研究结果表明：高碳同系物比例的增加，聚合物平均粒径增大，低碳同系物比例的增加，胶束数目增多，由胶束成核（包括均相成核）而形成的聚合物粒径分布变宽，而对在种子上增长的聚合物粒径分布无影响。     

苯甲酸乙烯酯与受电子的可逆加成－断链链转移共聚合

采用二硫代苯甲酸苄酯和偶氮二异丁腈组成的引发体系，以可逆加成－断链链 转移聚合方法合成了苯甲酸乙烯酯与马来酸酐及N－取代马来酰亚胺的交替共聚物 。结果表明，所行聚合物具有预期分子量，分子量分布在1.1～1.3之间。在较低转 化率下所得的聚合物均为交替结构，而与摩尔设料比无关。     

不同干燥过程对超细TiO2粉体性质的影响

考察了采用不同干燥工艺制备的TiO2粉体在粒子形貌、颗粒大小与分布、晶相组成以及比表面积和孔结构等织构和结构性质方面的差异。结果表明，利用常规的干燥方法，由水凝胶脱水所得的颗粒，颗粒间严重团聚，颗粒粒径大且分布不均匀，比表面积和孔体积最小；由醇凝胶直接脱水，则可以显著提高粉体的织构性能．而采用超临界流体干燥法则可以进一步提高粉体的性能，比表面积由水凝胶的4．88m2·g－1增大到113．8m2·g－1，提高了近30倍；孔体积由0．027cm3·g－1增大到0．41cm3·g-1．大约提高了15倍；而且其能够有效地防止粒子间的团聚，较好地保持了湿凝胶的网络结构，使颗粒尺寸降低且分布均匀，可重复性好．     

超细银－金复合颗粒增强酶生物传感器的研究

用琥珀酸二异辛酯磺酸钠／环已烷反胶束体系合成憎水纳米银－金复合颗粒， 并用此纳米银－金颗粒与聚乙烯醇缩丁醛构成复合固酶模基质，用溶胶－凝胶法固 定葡萄糖氧化酶，构建葡萄糖生物传感器。实验表明，纳米憎水银－金颗粒可以大 幅度提高固定化酶的催化活性，响应电流从相应浓度的几十纳安增强几万纳安。探 讨了纳米颗粒效应在固定化酶中所起的作用，为纳米颗粒在生物传感器领域中的应 用提供了可参考的实验和理论依据。     

苯甲酸乙烯酯与受电子的可逆加成－断链链转移共聚合

采用二硫代苯甲酸苄酯和偶氮二异丁腈组成的引发体系,以可逆加成－断链链 转移聚合方法合成了苯甲酸乙烯酯与马来酸酐及N－取代马来酰亚胺的交替共聚物 。结果表明,所行聚合物具有预期分子量,分子量分布在1.1～1.3之间。在较低转 化率下所得的聚合物均为交替结构,而与摩尔设料比无关。     

带电胶体粒子的电热分布：非线性积分方程

多电解质溶液中带电胶体料一子的电势分布由球形Ｐｏｓｉｓｓｏｎ－Ｂｏｌｔｚｍａｎｎ方程描述。ＰＢＥ是一个非线性的微分方程组难以求得其解析解。本文采用非线性Ｐ－Ｂ积分方程，计算电势分布的数值解。     

纳米颗粒增强的葡萄糖生物传感器

研制的纳米增强葡萄糖传感器是用纳米憎水Ａｕ颗粒。亲水Ａｕ颗粒、憎水ＳｉＯ_２颗粒以及Ａｕ和－ＳｉＯ_2颗粒混合与聚乙烯醇缩丁醛（ＰＶＢ）构成复合固酶膜基质,用溶胶－凝胶法固定葡萄糖氧化酶（ＧＯＤ）,组成葡萄糖生物传感器．实验表明,纳米颗粒可以大幅度提高固定化酶的催化活性,响应电流从相应浓度的几十纳安增强到几千纳安,电极响应迅速, １ｍｉｎ达到稳态,探讨了纳米颗粒效应在固定化酶中所起的作用,开辟了制备直接电子传递第三代生物传感器的新途径和纳米颗粒应用的新领域。     

应用于药物传输系统的聚合物纳米粒

载药聚合物纳米粒具有良好的组织靶向性和缓控释性，本文简要介绍了聚合物纳米粒在药物传输系统中的特点，综合分析并讨论了纳米粒的制备技术及应用，展望了今后的研究方向。     

新型高活性催化剂乙烯气相聚合的研究（Ⅱ）——改性剂,预聚…

研究了新型高活性乙烯气相聚合催化剂ＴｉＣｌ４／ＭｇＣｌ２／ＺｎＣｌ２／ＳｉＣｌ４醇／Ａｌ（ｉ－Ｂｕ）３体系中不同醇、不同Ｃ２Ｈ５ＯＨ／Ｔｉ摩尔比和正丁醚对聚合反庆及产物颗粒形态的影响，研究了预聚合反应及乙烯气相聚合反应规律，用扫描电镜和图象分析对催化剂、预聚物和聚合产物的形态和颗粒分布的研究表明：新型高活性催化剂和经预聚合制得的乙烯气相聚合物的颗粒形态类似球形，颗粒长短轴比值和大小粒径比值相近。     

Specifics of change in the surface area of amorphous poly(vinyl chloride) during its inelastic deformation

A direct microscopic observation procedure was used to study the processes of deformation and shrinkage of poly(vinyl chloride) above its glass transition temperature. Prior to stretching or contraction of the polymer, its surface was decorated with a thin (10–15 nm) metal layer. As a result of subsequent deformation (shrinkage), the decoration underwent structural rearrangements, which were detected by means of direct microscopic examination. These rearrangements contain information on the mechanism of deformation of the polymer substrate. In particular, the procedure makes it possible to characterize the process of development of the interface in the polymer during deformation and the reverse process of interface contraction during the shrinkage of the material. It was found that, in the case of an increase in the interfacial area, its growth is accompanied by a growth in imperfection of the polymer surface layer. These defects can concentrate mechanical stress, thus strongly affecting the fragmentation of the metal decoration on the polymer surface. It was shown that the surface defects could be eliminated by annealing of the polymer above its glass transition temperature. The introduction of a plasticizer that decreases the glass transition temperature below the deformation temperature likewise prevents the development of these defects during an increase in the surface area of the polymer in the process of its inelastic deformation.     

Tunable helical assemblies of L-alanine methyl ester-containing polyphenylacetylene

The self-assemblying behaviors of L-alanine methyl ester-containing polyphenylacetylene (PPA-Ala, in Chart 1 ) were investigated upon the evaporation of its solvent on mica and on air/water interfaces. The introduction of chiral amino acid attachments to the polyphenylacetylene backbone induced a helical conformation of the backbone, which was stabilized by various noncovalent interactions, especially hydrophobic effect and hydrogen bonds. The helicity of the polymer was further amplified in its higher-order self-assemblies as the formation of helical fibers on the surface of mica upon natural evaporation of its THF solution. By LB technique, the polymer chains were guided to form ordered parallel ridges and highly aligned, with their helical conformation still remaining. The reorganization of the chiral polymer chains on air/water interface was associated with the additional hydrophobic effect of PPA-Ala on an air/water interface. The polymer backbones had to adopt different arrangements to minimize their contact with water, and this adjustment led to the formation of aligned polymer ridges under proper surface pressure.     

Immobilization of tyrosinase on poly(indole-5-carboxylic acid) evidenced by electrochemical and spectroscopic methods

A conducting, polymeric film of poly(indole-5 carboxylic acid) has been prepared by electrochemical polymerization for covalent immobilization of an enzyme belonging to the family of phenoloxidases-tyrosinase. The polymer was characterized by cyclic voltammetry, UV-VIS and Raman spectroscopy in a buffer solution. As the polymer contains pendant carboxylic groups one-step carbodiimide method was used to immobilize tyrosinase on the polymer matrix. Immobilization of tyrosinase was confirmed by surface enhanced resonance Raman scattering spectra (SERRS) and by cyclic voltammetry as well. Tyrosinase was shown to retain its biological activity when being immobilized on the polymer surface. As proved by the electrochemical and spectroelectrochemical (UV-VIS) experiments, tyrosinase covalently bonded to the polymer matrix effectively catalyzes oxidation of catechol. The reduction current of o-quinones was measured as a function of catechol concentration. The linear dependence was found to be 15 microM of catechol with sensitivity of 250 mA/M cm2.     

How silanization of silica particles affects the adsorption of PDMS chains on its surface

A series of six fumed silica types, with different surface areas in the 50–400 m²/g range, were modified by grafting with trimethylchlorosilane. The grafting reaction was controlled by elemental analyses, surface hydroxyl titration, and combustion techniques. The silica surface energy was determined as a function of silanization degree by inverse gas chromatography (IGC). Adsorption of a series of poly(dimethylsiloxane) elastomers with molecular weights ranging between 4 and 420 kg/mol on silica was followed using flow microcalorimeter (FMC). IGC results show that free adsorption energies of two series of alkanes and siloxanes as well as the dispersive component of the surface energy were found to decrease monotonously with surface silanization and so does the polymer molar heat of adsorption. FMC results indicate, however, that the conformation of the macromolecules on silica depends on the silica surface area but remains unaffected by the surface treatments. A given polymer chain was found to remain adsorbed on the surface preserving its same conformation until its molar heat of adsorption falls bellow a critical value. These findings offer a better monitoring of surface–polymer interactions as it defined a comprehensive relationship between the degree of modifications of the filler surface and polymer adsorption conditions. © 2010 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2010     

Nanostructuring effect of plasma and solvent treatment on polystyrene

Plasma treatment of polymer surfaces is used to control the generation of topological surface structures: stripes, starlike morphologies, and pinnacles in the range from 100 nm up to several micrometers. These protrusions arise when the plasma-treated polymer surface is exposed to an organic solvent (liquid or vapor phase). The distribution density and the height of the observed structures on the surface are functions of the power density of the plasma reactor and the exposure time to the plasma, the duration of the development process, the type of the polymer, and its manufacturing. We suggest that the structures are generated by selective swelling of less cross-linked areas within the polymer surface and not by rearrangement or dissolution of polymer chain fragments created by plasma, or by amphiphilic moieties due to oxidation as a consequence of plasma treatment.     

Dual mode bioreactions on polymer nanoparticles covered with phosphorylcholine group

We investigated the preparation of polymer nanoparticles covered with phosphorylcholine (PC) groups and the immobilization of proteins in order to observe dual mode bioreactions on the nanoparticles. For the surface modification on the nanoparticles, a water-soluble amphiphilic phospholipid polymer with PC groups as a hydrophilic moiety was synthesized. In this polymer, an active ester group, which can immobilize proteins, was introduced. Using the phospholipid polymer as a solubilizer, poly(L-lactic acid) nanoparticles were prepared from its methylene chloride solution in an aqueous medium by the solvent evaporation method. The diameter of the nanoparticles was ca. 200 nm and the surface was covered with the PC groups and active ester groups. Proteins could immobilize on the nanoparticles under mild conditions by the reaction between the active ester group and amino group in the proteins. Both an antibody and enzyme were immobilized on the nanoparticles and bioreactions such as the antigen/antibody reaction and enzymatic reaction were observed. When an antigen was added to the suspension of the nanoparticles, aggregation of the nanoparticles occurred and then they precipitated. Also, the enzymatic reaction proceeded well when the enzyme substrate was added to the suspension. Based on these results, we provided polymer nanoparticles functionalized with both the antibody and enzyme, and the dual mode bioreactions could occur. We concluded that the novel polymer nanoparticles could be used for nano-/micro-scaled diagnostic and medical treatment systems.     

渗透汽化膜表面化学结构设计研究

综述了近年来渗透汽化膜表面结构设计调控的研究进展。膜表面结构的设计与优化是提高其分离性能的重要方法。然而高分子表面具有环境响应性,这往往导致高分子材料在使用环境中失去在表面设计时所期待的性能。因此,高分子膜表面的环境响应性是在对膜表面进行设计和调控过程中必须考虑的因素。本文介绍了渗透汽化膜表面结构设计的方法,重点阐述了高分子膜表面环境响应特性对膜表面性质以及渗透汽化性能的影响。指出了利用高分子膜的表面重构行为可以对其表面结构进行优化,从而有效地提高膜的分离选择性。     

Novel surface fixation technology of hydrogel based on photochemical method: Heparin-immobilized hydrogelated surface

This article reports a novel photoinduced surface process technology enabling simultaneous hydrogel formation and its surface fixation on polymeric substrates. The process consists of layering two different types of photoreactive coatings on a polymeric surface, an azidophenyl-bearing polymer as an adhesive layer and cinnamoylated copolymer as a hydrogel layer, and subsequent UV irradiation. The photoreactive adhesive polymer coated on a substrate is poly(m-azidostyrene), in which photoreaction of phenyl azido groups is responsible for the chemical bonding between the substrate and hydrogel. N,N-dimethylacrylamide copolymer containing cinnamate moieties in their side chains, which undergo photocrosslinking via intermolecular dimerization, was applied as an overcoat on the adhesive layer. UV irradiation resulted in the formation of hydrogel chemically bonded onto the substrate. This was confirmed by ESCA measurements. A heparin-immobilized hydrogelated surface with controlled release characteristics was demonstrated. © 1993 John Wiley & Sons, Inc.     

Inorganic surface nanostructuring by atmospheric pressure plasma-induced graft polymerization

Surface graft polymerization of 1-vinyl-2-pyrrolidone onto a silicon surface was accomplished by atmospheric pressure (AP) hydrogen plasma surface activation followed by graft polymerization in both N-methyl-2-pyrrolidone (NMP) and in an NMP/water solvent mixture. The formation of initiation sites was controlled by the plasma exposure period, radio frequency (rf) power, and adsorbed surface water. The surface number density of active sites was critically dependent on the presence of adsorbed surface water with a maximum observed at approximately a monolayer surface water coverage. The surface topology and morphology of the grafted polymer layer depended on the solvent mixture composition, initial monomer concentration, reaction temperature, and reaction time. Grafted polymer surfaces prepared in pure NMP resulted in a polymer feature spacing of as low as 5-10 nm (average feature diameter of about 17 nm), an rms surface roughness range of 0.18-0.72 nm, and a maximum grafted polymer layer thickness of 5.5 nm. Graft polymerization in an NMP/water solvent mixture, however, resulted in polymer feature sizes that increased up to a maximum average feature diameter of about 90 nm at [NMP] = 60% (v/v) with polymer feature spacing in the range of 10-50 nm. The surface topology of the polymer-modified silicon surfaces grafted in an NMP/water solvent mixture exhibited a bimodal feature height distribution. In constrast, graft polymerization in pure NMP resulted in a narrow feature height distribution of smaller-diameter surface features with smaller surface spacing. The results demonstrated that, with the present approach, the topology of the grafted polymer surface was tunable by adjusting the NMP/water ratio. The present surface graft polymerization method, which is carried out under AP conditions, is particularly advantageous for polymer surface structuring via radical polymerization and can, in principle, be scaled to large surfaces.     

Surface characteristics of a self-polymerized dopamine coating deposited on hydrophobic polymer films

This study aims to explore the fundamental surface characteristics of polydopamine (pDA)-coated hydrophobic polymer films. A poly(vinylidene fluoride) (PVDF) film was surface modified by dip coating in an aqueous solution of dopamine on the basis of its self-polymerization and strong adhesion feature. The self-polymerization and deposition rates of dopamine on film surfaces increased with increasing temperature as evaluated by both spectroscopic ellipsometry and scanning electronic microscopy (SEM). Changes in the surface morphologies of pDA-coated films as well as the size and shape of pDA particles in the solution were also investigated by SEM, atomic force microscopy (AFM), and transmission electron microscopy (TEM). The surface roughness and surface free energy of pDA-modified films were mainly affected by the reaction temperature and showed only a slight dependence on the reaction time and concentration of the dopamine solution. Additionally, three other typical hydrophobic polymer films of polytetrafluoroethylene (PTFE), poly(ethylene terephthalate) (PET), and polyimide (PI) were also modified by the same procedure. The lyophilicity (liquid affinity) and surface free energy of these polymer films were enhanced significantly after being coated with pDA, as were those of PVDF films. It is indicated that the deposition behavior of pDA is not strongly dependent on the nature of the substrates. This information provides us with not only a better understanding of biologically inspired surface chemistry for pDA coatings but also effective strategies for exploiting the properties of dopamine to create novel functional polymer materials.