XPS和AES研究A3钢表面杂多酸钝化膜

通过比较多种杂多酸及铬酸盐等纯化剂的钝化效果，发现Ｈ３ＰＭｏ１２Ｏ４０是一种优良的纯化剂。在５５℃，ｐＨ１．０的条件下，Ａ３钢在２０ｇ／Ｌ的Ｈ３ＰＭｏ１２Ｏ４０溶液中能形成致密的耐蚀性保护膜。ＡＥＳ结合Ａｒ＾＋溅射测得膜的元素组成为：Ｐ１．９％，Ｍｏ１７．９％，Ｏ６９．６％，Ｆｅ１０．７％．ＸＰＳ测得膜中Ｍｏ以Ｍｏ（Ⅵ）、Ｍｏ（Ｖ）ｔ Ｍｏ（Ⅳ）三种氧化态存在。红外及Ｒａｍａｎ光谱表明，膜的主要振     

AES和XPS研究Cu-Sn-P镀层表面PMTA复合膜

本文运用ＡＥＳ和ＸＰＳ分析了不同缓蚀剂对Ｃｕ－Ｓｎ－Ｐ仿金镀层表面进行处理所形成的配合物保护膜的组成,并采用加速腐蚀实验和ＬＳＶ研究了这些不同保护膜的抗腐蚀能力。结果表明：采用１＝苯基－５－巯基四氮唑（ＰＭＴＡ）钝化处理后,不仅增强了镀层耐盐溶液和酸性气体的腐蚀能力,又不影响镀层表面的金黄色外观,其防变色效果优于苯并三氮唑（ＢＴＡ）、２－巯基苯并噻唑（ＭＢＴ）和２－氨基嘧啶（２－ＡＰ０。ＰＭＴＡ／     

扫描探针显微学在材料表面纳米级结构研究中的新进展

应用扫描探针显微技术（ＳＰＭ）「包括扫描隧道显微镜（ＳＴＭ）、原子力显微镜（ＡＦＭ）、磁力显微镜（ＭＦＭ）等」,比较系统地研究了一些无机、有机和生物材料的表面精细结构;在极高分辨率的水平上,解释了如Ｃ６０Ｌａｎｇｍｕｉｒ－Ｂｌｏｄｇｅｔｔ膜、有机磁性薄膜的样品制备、形成条件的关系;研究并揭示了碱金属与半志体表面吸附相互作用,红细胞表面结构等;拓宽了扫描探针显微技术的范围,在实验方法和研究成果上具有     

PAN基活性炭纤维的表面及其孔隙结构解析

通过氮吸附等温线、Ｘ射线光电子能谱以及扫描电子显微镜（ＳＥＭ）对聚丙烯腈（ＰＡＮ－Ｐｏｌｙａｃｒｙｌｏｎｉｔｒｉｌｅ）－基活性炭纤维（ＡＣＦ－Ａｃｔｉｖａｔｅｄ Ｃａｒｂｏｎ Ｆｉｂｅｒ）的表面和孔隙结构进行了分析,结果表明吸附测量可以提供有关碳质吸附剂的孔结构复杂性;通过ＸＰＳ对ＰＡＮ基ＡＣＦ的表面官能团的种类及含量进行了表征,由ＳＥＭ对ＰＡＮ基ＡＣＦ的表面以及断面的孔隙结构进行直拉观察,提供了     

非晶态高聚物的椭圆偏振光谱和光学折射率的测定

应用紫外－可见光区的椭圆偏振光谱（ＳＥ）方法测定了非晶态高聚物ＰＭＭＡ和ＰＣ的固体光学性质，并由无体系理论模型计算救是薄膜材料的折射率谱，确定在所用波长范围内ＰＭＭＡ和ＰＣ的ｎ值分别为１．３２－１．５３和１．４１－１．９４，研究表明非晶态高聚物的大分子链（段）化学组成和结构不同，使人有不同的折射率变化，产生不同的光学色散现象。     

金刚石薄膜中SP~2／SP~3键价比拉曼光谱分析

金刚石薄膜中ＳＰ￣２／ＳＰ￣３键价比拉曼光谱分析张兵临Ｈ，Ｍ．Ｐｈｉｌｌｌｉｐｓ（郑州大学物理系郑州４５００５２）ＡｎａｌｙｓｉｓｏｆＳＰ￣２／　ＳＰ￣２／ＳＰ￣３ＢｏｎｄｉｎｇＲａｔｉｏｉｎＤｉａｍｏｎｄＴｈｉｎＦｉｌｍｓｂｙＲａｍａｎＳｐｅｃｔｒ...     

电场对Au—Ag薄膜结构影响的AFM和VAXPS研究

利用原子力显微镜（ＡＦＭ）和变角Ｘ射线光电子谱（ＶＡＸＰＳ）技术研究了Ａｕ－Ａｇ／ＳｉＯ２体系在直流电场作用下，Ａｕ，Ａｇ电迁移的特点及所引起的薄膜结构的变化，观察到较低温度下Ａｕ，Ａｇ聚集状态的显著变化，发现电迁移过程中Ａｕ－Ａｇ薄膜与ＳｉＯ２基底之间存在界面化学反应，膜层中Ａｕ，Ａｇ，Ｓｉ等元素的化学状态发生了相应的变化，这些结构表明ＳｉＯ２表面上Ａｕ－Ａｇ复合薄膜电迁移不只是一个水平方向的扩     

扫描显微探针

 随着１９８２年世界上第一台原子分辨的隧道扫描显微镜（ＳＴＭ）问世,掀起了对物质表面微结构研究的热潮,而且蔓延到表面化学以及生物大分子等领域．同时对ＳＴＭ原理及检测技术的推广,促使了原子力显微镜（ＡＦＭ）、近场光学显微镜（ＳＮＯＭ）的发明．现在,以ＳＴＭ、ＡＦＭ、ＳＮＯＭ为代表的高分辨显微镜已经形成了一类新的显微成像技术──扫描探针显微术（ＳＰＭ）．ＳＰＭ最显著的特点就是采用一个极微小的探针（针尖一般在纳米尺度）,在样品表面极小的距离内移动,同时获得样品表面信息．当这极小的探针与样品表面的相互作用强烈依赖于极小的距离（大约是指数关系）,仪器的稳定性则是获得理想图像的关键.     

尼龙1010－聚四氢呋喃多嵌段共聚物的ESCA研究

尼龙１０１０－聚四氢呋哺多嵌段共聚物（ＰＡ－ＰＴＭＧ）是一种性能良好的聚合物。本文用Ｘ射线光电子能谱（ＥＳＣＡ）和计算机分峰技术研究了不同软硬段分子量的ＰＡ－ＰＴＭＧ的表面化学组成，进行了试样ＥＳＣＡ谱峰归属的确定。结果表明，本体嵌段效果较好，但在样品表面上Ｏ／Ｎ原子比大于体相Ｏ／Ｎ原子比，即软段富集于表面，并且分相程度高的试样较分相程度低的试样其软段在表面富集得更多。     

氰基团修饰的苯腙类有机分子掺杂极化聚合膜光学非线性的研究

采用实时测量光学二次谐波产生（ＳＨＧ）和吸收光谱的方法对苯腙类有机分子ＮＤＡ及一种新合成的经氰基团修饰的有机分子ＣＮＤＡ掺杂ＰＭＭＡ极化聚合膜的非线性光学性质进行了研究。实验中发现两种掺杂极化聚合膜的最佳电晕极化温度均低于它们的玻转温度,ＣＮＤＡ／ＰＭ－ＭＡ极化掺杂聚合膜的χ（２）较ＮＤＡ／ＰＭＭＡ极化聚合膜的大。结合极化前和极化后吸收峰强度的变化,得到ＣＮＤＡ分子的非线性极化率β约为１４６×１０－３０ｅｓｕ。在撤离极化场后,ＣＮＤＡ／ＰＭＭＡ的二次谐波强度的弛豫也比ＮＤＡ／ＰＭＭＡ的慢     

Preferential surface segregation of homopolymer and copolymer blend films

Surface film properties of the homopolymers polystyrene (PS), poly(methyl methacrylate) (PMMA), poly(butyl methacrylate) (PBMA) and the copolymer poly(methyl methacrylate)-co-poly(butyl methacrylate) (PMMA-co-PBMA) and their blends with PS have been examined by atomic force microscopy (AFM) and contact angle measurements. The total and the Lifshitz-van der Waals, acid and base components of the surface free energy together with the work of adhesion and its components, the cohesive energy density and the solubility parameters of the homopolymer, copolymer and blend films were determined. Films of about 3 μm were considered. The results are discussed in terms of surface migration mechanisms based on surface free energy and solubilities of the polymers in the solvent, toluene in this paper. AFM imaging and contact angles revealed surface enrichment at the air polymer interface of PBMA for both the PS/PBMA blend and the copolymer PMMA-co-PBMA, whereas the PS/PMMA and PS/PMMA-co-PBMA blend film surfaces show island-like phase-separated structure of typical size 27.4-86.5 nm in diameter and 6.9-15.6 nm in height for PS/PMMA, while for PS/ PMMA-co-PBMA film surface the typical size is 49.6-153.3 nm in diameter and 1.6-14.2 nm in height.     

Annealing effects on the surface morphologies of thin PS/PMMA blend films with different film thickness

The surface morphology evolution of three thin polystyrene (PS)/polymethyl methacrylate (PMMA) blend films (<70 nm) on SiO_x substrates upon annealing were investigated by atomic force microscopy (AFM) and some interesting phenomena were observed. All the spin-coated PS/PMMA blend films were not in thermodynamic equilibrium. For the 67.1 and the 27.2 nm PS/PMMA blend films, owing to the low mobility of the PMMA-rich phase layer at substrate surfaces and interfacial stabilization caused by long-range van der Waals forces of the substrates, the long-lived metastable surface morphologies (the foam-like and the bicontinuous morphologies) were first observed. For the two-dimensional ultrathin PS/PMMA blend film (16.3 nm), the discrete domains of the PS-rich phases upon the PMMA-rich phase layer formed and the secondary phase separation occurred after a longer annealing time.     

Simultaneous imaging for surface and internal structure of polymer blend thin films

A novel experimental technique for three-dimensional (3D) visualization of phase-separated structure of polymer blend thin film was proposed. Polystyrene/poly(methyl methacrylate) (PS/PMMA) blend thin films with the thickness of approximately 100 nm were cut at extremely low angle by utilizing surface and interface cutting analysis system (SAICAS), and the cross-section was exposed as gradient surface with the width of approximately 2.5 μm. SFM investigation for the grazing cross-section imaged the detailed internal and surface phase separated structure of the (PS/PMMA) blend thin films on one image.     

Retardation of enzymatic degradation of microbial polyesters using surface chemistry: effect of addition of non-degradable polymers

The effects of addition of non-degradable polymers on the rate of enzymatic erosion for the poly(3-hydroxybutyrate-co-3-hydroxyvalerate) [P(3HB-co-3HV)] have been studied at 37 °C and pH 7.4 in the aqueous solution of an extracellular PHB depolymerase from Alcaligenes facalis. Polystyrene (PS) or poly(methyl methacrylate) (PMMA) was selected as a minor component (5 wt%) in a blend because of their non-enzymatic activity. Enzymatic degradation behaviors of the “as-cast” and “annealed” blend films were investigated using atomic force microscopy and weight loss measurements. Although the spherulites of P(3HB-co-3HV) cover all blend film surfaces throughout, the retardation of biodegradation in the P(3HB-co-3HV)/PS blend films was detected from morphological observation and weight loss measurement for both as-cast and annealed blend films while there was little difference between the P(3HB-co-3HV)/PMMA blend and pure P(3HB-co-3HV). Since the enzymatic degradation of P(3HB-co-3HV) initially occurs by a surface erosion process, these degradation behaviors were explained by the surface structure of blend films measured by X-ray photoelectron spectroscopy. The surface of P(3HB-co-3HV)/PS blend films revealed an excess of PS, whereas the surface of P(3HB-co-3HV)/PMMA blend films was nearly covered by P(3HB-co-3HV). It was concluded, therefore, that the PS, which exists within P(3HB-co-3HV) spherulites at surface acts as a retardant of enzymatic attack to the surface of the blend film.     

Interaction of Domains in Ternary Polymer Melt Blends with Separate Dispersions of the Inner Phases

The morphology evolution in three immiscible ternary polymer systems characterized by separate dispersions of the dispersed phases (i.e., no encapsulation phenomena takes place) was characterized. The components used were three of the following: commercial atactic poly(methyl methacrylate) (PMMA) and polystyrene (PS), crystallizable poly(butylene terephthalate) (PBT) and isotactic polypropylene (PP) and glass microspheres (GMS). In System I PMMA/PS/PP (primary dispersed phase/matrix/secondary, or minor, dispersed phase), all of the components were liquid on blending at 190°C. In System II PP/PS/PBT and System III PP/PSyGMS, at 190°C, the minor PBT and GMS dispersed phases were nondeformable. It was shown that small portions (0.5–1.0 wt%) of the PP minor dispersed phase added to the binary PMMA/PS blend produced a dual action: (a) transition of the PMMA dispersed phase to a cocontinuous one and (b) simultaneous substantial (up to a 6-fold) growth of the degree of dispersion of the blend. Moreover, these effects were accompanied by about a three-fold reduction of the threshold PMMA concentration (C*) at which it formed its own co-continuous phase in the ternary blend compared to that in the PMMA/PS binary mixture. The observed phenomena took place regardless of whether the domains of the minor dispersed phase were liquid (System I) or solid (Systems II and III), and was strongly related to the domain sizes of this phase and blend composition. A mechanism underlying the outlined behavior is proposed.     

End group effect on surface and interfacial segregation in PS-PMMA blend thin films

Thin films of polystyrene (PS)/poly (methyl methacrylate) (PMMA) blends with different end groups were investigated using ToF-SIMS and AFM. PS with -OH and -NH₂ end groups were blended in toluene solvent with pure PMMA homopolymer, and PMMA having anhydride end group. The ToF-SIMS spectra of PS-OH/PMMA resembled that of pure PS-PMMA blends showing an increase of PMMA intensity after annealing. On the contrary, the PS-NH₂ blended with PMMA showed an increase in PS intensity on the surface after annealing. The ToF-SIMS spectra were similar to that of a pure PS-PMMA di-block copolymer. These results indicate copolymer formation at the surface. The PS-NH₂ with PMMA-anhydride blend spectra showed very slight changes in spectra before and after annealing and the AFM images revealed spinodal bi-continuous structures on the surface before and after annealing. The copolymer formation is found to occur in the as-cast film itself and not after thermal treatment.     

表面增强拉曼光谱研究高分子共混物薄膜相结构

采用拉曼光谱法研究了由聚苯乙烯(PS)/聚甲基丙烯酸甲酯(PMMA)的四氢呋喃(THF)溶液在玻璃基板上旋转涂膜得到的共混物薄膜。应用显微共焦拉曼光谱,根据PS在1604,1585cm-1处苯环的伸缩振动峰和PMMA在1728cm-1处羰基的伸缩振动峰,可以确定薄膜(厚度约为800nm)表面海岛状相结构的组分分布信息。另外,还对210℃下PS/PMMA(30/70)共混物薄膜退火过程中表面的变化进行了分析。采用表面增强拉曼散射效应对高聚物的增强作用得到了薄膜(厚度约为400nm)的Raman光谱,并且成功地对其组成进行了分析。     

Effect of Polymer-Substrate Interactions on the Surface Morphology of Polymer Blend Thin Films: Comparison between Simulation and Experiment

Microphase and macrophase separation phenomena can simultaneously appear in ABA/C copolymer blend systems due to the immiscibility among monomers A, B, and C. In this work, the surface morphologies and compositions of ABA/C blend thin films confined between two walls, which were used to mimic SEBS/PMMA films, have been simulated by a lattice Monte Carlo (MC) method. The effect of the polymer-wall interaction on the surface morphologies and compositions of thin films was investigated as a function of blend composition and film thickness. It is shown that the simulated surface morphologies of thin films resulting from the macrophase separation between copolymer ABA and homopolymer C and the microphase separation between block A and block B in ABA copolymer are similar to the experimental surface morphology of SEBS/PMMA polymer blend films observed by atomic force microscope (AFM). The effect of substrate on the surface morphologies by MC simulation is qualitatively consistent with the experimental results. The composition profiles of thin films are given to characterize the micro- and macrophase separation in thin films. It is indicated that the surface energy of the substrate (substrate/air) plays a crucial role on the surface composition. For a fixed surface, the adsorptions of polymer on the substrate and film thickness are also important.     

Molecular dynamics simulation studies of the miscibility and thermal properties of PMMA/PS polymer blend

This investigation is an attempt to improve our understanding of the thermal properties of PMMA (Polymethyl methacrylate) by using PS(Polystyrene); the miscibility of PMMA/PS polymer blend is studied. Our work aims to study the impact of the percentage of PMMA/PS polymer blend on the simulated values of the glass transition temperature (Tg) using the dilatometric method. Compass was chosen as the force field (second category force field). The results reveal a single value of the glass transition temperature Tg that is found for all the curves of the PMMA/PS blend system (molar ratio: (50:50, 60:40, 54:46 and 80:20)); this could be a good criterion for predicting the miscibility. Additionally, the solubility parameters of PMMA and PS are calculated and used to obtain the Flory–Huggins parameter, and the morphology of our polymer blend is simulated using the dissipative particle dynamics method (DPD). Our results exhibit an increase in the Tg of PMMA whenever PS is added; hence, we can confirm the miscibility of the PMMA/PS polymer system.     

Microhardness Studies of the Interphase Boundary in Rubber‐Softened Glassy Polymer Blends Prepared with/without Compatibilizer

Abstract

The interphase boundary of incompatible polymer blends such as poly(methyl methacrylate) (PMMA)/natural rubber (NR) and polystyrene (PS)/NR, and of compatible blends such as PMMA/NR/epoxidized NR (ENR) and PS/NR/styrene–butadiene–styrene (SBS) block copolymer, where ENR and SBS were used as compatibilizers, was studied by means of microindentation hardness (H) and microscopy. Cast films of neat PMMA and PS, and blended films of PMMA/NR, PS/NR, PMMA/NR/ENR, and PS/NR/SBS were prepared by the solution method using a common solvent (toluene). Hardness values of 178 and 173 MPa were obtained on the surfaces of the neat PMMA and PS, respectively. After the inclusion of soft phases, the binary (incompatible) and the ternary (compatible) blend surfaces show markedly lower H‐values. Scanning electron and optical microscopy reveal a clear difference at the phase boundary of the surface of compatible (smooth boundary) and incompatible (sharp boundary) blends. The compatibilized blends were characterized by using microhardness measurements, as having the thinnest phase boundary (～30 µm), while incompatible blends were shown to present a boundary of about 60 µm. The hardness values indicate that the compatibilizer is smoothly distributed across the interface between the two blend components. Results highlight that the microindentation technique, in combination with microscopic observations, is a sensitive tool for studying the breadth and quality of the interphase boundary in non‐ or compatibilized polymer blends and other inhomogeneous materials.