嵌段共聚物聚己内酯-聚乙二醇-聚己内酯的合成和表征

以聚乙二醇(PEG)为引发剂在辛酸亚锡催化下引发己酸内酯开环聚合,制备PCL(聚己内酯)-PEG-PCL两亲三嵌段共聚物(PECL).采用红外光谱、体积排阻色谱及核磁共振对该共聚物进行表征,结果表明所合成共聚物具有预期结构.采用差热分析和原子力显微镜研究聚合物的微相分离结构;利用动态光散射测定了共聚物在水中自组装生成的纳米聚集体的粒径.     

In situ AFM observation of BSA adsorption on HOPG with nanobubble

Nanobubbles have been proven existent at the liquid/solid interface, and become a focus of research on varied interfacial processes. In the present work, by observing in situ with atomic force microscope (AFM), we found that nanobubbles could influence the adsorption process of bovine serum albumin (BSA) on hydrophobic surface of highly ordered pyrolytic graphite (HOPG). BSA could adsorb evenly, and coexist with nanobubbles at water/HOPG interface. After removing nanobubbles by injecting ethanol, some hollows were found in the BSA layers at the same positions of nanobubbles existing previously. These hollows were about 8 nm in depth and dozens of nanometers in diameter. The correlation coefficient between the areas of nanobubbles and that of the corresponding hollows reached 0.88―0.94, which strongly supported the assumption that the hollows were indeed caused by the nanobubbles. Moreover, the BSA molecules formed rings around the nanobubbles, suggesting the preference of BSA adsorption onto the contact line at water/HOPG interface.     

DNA在不同衬底表面的固定

分别将DNA梳直在APS处理的云母和巯基乙胺处理的金膜表面,讨论了巯基乙胺浓度对金膜表面吸附DNA的影响.AFM图像表明,DNA能够有效吸附在处理过的两种衬底表面,经过盖玻片拉伸后,DNA能沿一定方向延伸,有较好的定向性.实验发现:处理金膜的巯基乙胺最佳浓度为5 mM,在该浓度下,DNA分布均匀,易于寻找,且巯基乙胺对金膜的破坏作用较小.     

PAM对CaCO3显微结构的影响

利用原子力显微镜(AFM)研究添加聚丙烯酰胺(PAM)后碳酸钙晶粒表面形貌的变化。观察实验所得图像发现加入PAM后碳酸钙晶体发生了较大的形貌变化。空白样品碳酸钙表面致密平整,而加入PAM的样品碳酸钙表面凸起和凹陷明显增多。结果表明,PAM对碳酸钙显微结构的影响与阻垢剂所具有的部分作用机理相似。     

原子力显微镜和扫描隧道显微镜兼容系统的研制

扫描隧道显微镜（ＳＴＭ）和原子力显微镜（ＡＦＭ）由于具有原子量级的分辨率,所以在表面物理,化学,生物学领域得到了越来越广泛的应用。但是,扫描隧道显微镜只能观察导电样品,这就限制了它的应用范围。     

界面缩聚法制备聚芳酯复合纳滤膜 III.NF-1复合纳滤膜的结构和性能

通过 Ｉ Ｒ, Ｘ射线衍射分别研究了复合纳滤膜致密层的化学结构及其与性能的关系。采用扫描电镜（ Ｓ Ｅ Ｍ ）和原子力显微镜（ Ａ Ｆ Ｍ ）分别对膜的断面、表面形态作了研究。     

电解液中Na2SiO3加入量对Ti6Al4V微弧氧化膜厚度及表面形貌的影响

在不同Na2SiO3含量的电解液体系下对Ti6Al4V合金进行微弧氧化.采用SEM和AFM分析氧化膜表面形貌及粗糙度,研究电解液中Na2SiO3含量对氧化膜厚度及表面形貌的影响.结果表明:随着电解液中Na2SiO3质量浓度从12 g.L-1增加到28 g.L-1,临界正向起弧电压逐渐降低,微弧氧化膜的厚度由31μm增加至88μm;氧化膜表面均匀分布着尺寸不等的微孔,并且随着Na2SiO3质量浓度的增加,微孔的数目增多,粗糙度增加.XRD分析显示氧化膜的相组成为锐钛矿以及金红石.     

Study on elastic modulus of individual ferritin

The mechanical property of individual ferritin was measured with force-volume mapping (FV) under contact mode of atomic force microscopy (AFM) in this work. The elastic modulus of individual ferritin was estimated by the Hertz mode. The estimated value of the elastic modulus of individual ferritin was about 250－800 MPa under a small deformation. In addition, the elastic modulus of individual ferritin was compared with that of the colloid gold nanoparticle.     

Effect of humidity on the surface adhesion force of inorganic crystals by the force spectrum method

Effect of relative humidity on the surface adhesion force of several inorganic crystals of mica, CaF₂ and KCl was studied by atomic force microscopy (AFM). The results showed that the magnitude of surface adhesion force is mainly dependent on the surface free energy of the adsorbed liquid film, but almost independent of the thickness of the film. Furthermore, the deliquescence on the crystal surface was investigated, which demonstrated the capability of the force spectrum method to monitor changes in ionic concentrations of adsorbed liquid film in real-time.     

用AFM观察小白鼠心肌核DNA片段的基因体外表达和垃圾DNA的相互作用

用AFM直接现场观察、体外表达等实验技术组合,观察到小白鼠（Balb/c）心肌核DNA片段的基因在体外表达过程中形成的n mRNA（n=9）线型链状复合体,处于垃圾DNA片段的特定的“翻译平台”上,其每种mRNA两端非共价键分别结合自己编码蛋白质（即分子开关）,中间的编码序列均非共价结合完全可解离的翻译活性因子等多种蛋白质：这些蛋白质可能均由垃圾DNA片段的极复杂的立体结构所形成的、匹配协同的、专一性蛋白质通路所调控,该通路对蛋白质按顺序分别进行特异性双向调控.核内n mRNA线型链状复合体在体外可翻译出LDH等蛋白质,并显示n mRNA翻译的“群体效应”.用AFM还观察到胞质制取的n mRNA（n=12）线型链状复合体（无垃圾DNA存在）,体外翻译出少量LDH等蛋白质,并显示n mRNA翻译的＂群体效应＂.本工作展示了未来运用AFM观察体外表达等生物学反应,研究基因表达与调控机制及其与垃圾DNA相互作用的前景.