聚醚砜酮薄膜热稳定性及热解动力学规律的研究

采用热重分析法对聚醚砜酮(PPESK)薄膜在氮气氛下的热分解反应进行了研究，结果表明，热分解反应最剧烈的温度区间在400℃～600℃之间，这也是热解炭化阶段的关键温度区间；温度高于600℃分解反应趋于缓和。动力学研究得出，PPESK分解过程为一级反应；以Kissinger最大失重速率法求得表观活化能为211．35kJ／mol；以Ozawa等失重百分率法求得10％～30％的失重率下反应表观活化能在152．31kJ／mol～274．43kJ／mol之间，频率因子1nA值在21．98min^-1-38．75min^-1之间，充分表明PPESK热稳定性很高，这也为炭化过程提供了重要动力学参数。     

聚醚砜醚酮酮树脂的结构与性能

用FT—IR、DSC、WAXD等方法研究了四种不同方法制备的聚醚砜醚酮酮(PESEKK)样品的结构与性能。研究表明,低温溶液缩聚得到的PESEKK为半结晶聚合物,其非晶部分较易溶于二氯乙烷等强极性有机溶剂;半结晶聚合物熔融冷却过程中很难再结晶;半结晶聚合物熔融淬冷,转变为无定型聚合物;熔融拉丝取向,也不能促使其结晶,但非晶链段被取向使IR分析4000cm^-1-1700cm^-1出现强烈倍频吸收峰;用DCE处理半结晶聚合物得到结晶度更高的聚合物样品。     

聚乙二醇丙烯酸酯表面改性聚醚砜酮微孔膜的结构和性能

为了提高聚醚砜酮(PPESK)微孔膜的亲水性和抗污性,采用紫外(UV)辐照引发聚乙二醇丙烯酸酯(PEGA)在膜上发生接枝和交联,在膜表面形成稳定的亲水层.利用场发射扫描电镜(SEM)研究了固定PEGA后PPESK膜表面形貌的变化.表面改性后PPESK膜的水接触角的降低表明PEGA的固定有利于提高其亲水性,蛋白质静态吸附实验显示膜的抗蛋白质污染能力增强,渗透实验表明膜表面较低数量的PEGA亲水链有利于提高PPESK微孔膜的水通量,膜的溶质截留率增大,截留分子量(MWCO)减小.     

以新型聚合物聚醚砜酮为前驱体膜材料制作的平板膜的实验过程分析

气体分离膜以其低能耗,投资小,设备简单,模块化等特点,在许多领域得到应用,如氢气的回收、富氧助燃、富氮、天然气脱湿、有机蒸汽分离。膜法分离气体是分离科学中发展最快的分支之一。     

PI薄膜在炭化过程中热解固态产物结构的X射线衍射分析

用Ｘ射线衍射技术测定了ＰＩ（聚酰亚胺）薄膜在炭化过程中热裂解固态产物结构的演变。据衍射峰随热解炭化温度的变化规律，发现该试样的分子链排列由层状的超分子结构转变为杂乱地无序状态。当加热温度达到７００℃时，观察到代表类似碳六方网面的（００２）衍射峰的出现，其衍射强度随热解炭化温度的升高而加强。同时，依据布拉格公式和谢东经验式所获得的微晶尺寸和面间距与热解炭化温度的依赖关系给予了表征。     

异丙醇溶液中电化学法制备类金刚石薄膜的研究

采用电化学方法,以分析纯的异丙醇溶液作为碳源,低温(60～70℃)常压条件下,在(100)硅片上沉积了类金刚石薄膜。利用扫描电子显微镜(SEM)、原子力显微镜(AFM)、拉曼光谱仪(Raman)和傅里叶变换红外光谱仪(FTIR)表征了薄膜的表面形貌和结构。结果表明,电解异丙醇溶液可以获得表面均匀致密且sp3碳含量较高的含氢类金刚石薄膜。     

360keV Ar^3＋离子辐照聚碳酸酯薄膜的红外光谱研究

用付里叶变换红外光谱研究了３６０ｋｅＶＡｒ~（３＋）离子辐照聚碳酸酯薄膜的化学结构变化。氩离子辐照剂量为１．３×１０~（１２）～６．５×１０~（１３）离子／ｃｍ~２。结果表明，化学降解是聚碳酸酯薄膜主要的结构变化。此外，氩离子辐照也形成了ＯＨ基团、新的羰基团和碳化。     

PI薄膜在经过程中热解固态产物结构的X射线衍射分析

用Ｘ射线衍射技术测定了ＰＩ薄膜在炭化过程中热裂解固态产物结构的演变。据衍射峰随热解炭化温度的变化规律，发现该试样的分子链排列由层状的超分子结构转变为杂乱地无序状态。当加热温度达到７００℃时，观察到代表类似碳六方网面衍射峰的出现，其衍射强度随热解炭化温度的升高而加强。     

硅掺杂辉光放电聚合物薄膜的成分结构分析

以H2、反式二丁烯(T2B)和四甲基硅烷(TMS)混合气体为工作气体,在不同TMS流量条件下,用低压等离子体增强化学气相沉积法制备了Si掺杂辉光放电聚合物(GDP)薄膜。采用傅里叶变换红外光谱表征了不同TMS流量下Si掺杂GDP薄膜的化学组成结构。X射线光电子能谱表征了Si掺杂GDP薄膜成分,分析了TMS流量对Si掺杂GDP薄膜化学结构与元素组成的影响。研究表明:薄膜中成功地掺入了Si元素;Si掺杂GDP薄膜中Si元素主要以Si-C,Si-H等键合形式存在;在TMS流量为0.5~2 mL/min(标准状态)的范围内,薄膜中Si的原子浓度为0.72%~1.35%;随着TMS流量的逐渐增加,薄膜中Si含量逐渐增大。     

降解性聚乙烯地膜降解过程中力学性能和化学结构的变化

采用力学性能测试和红外光谱法对自研的光和生物双降解聚乙烯地膜在自然降解过程中的力学性能和化学结构变化进行了研究。结果表明,在降解初期使塑膜力学性能能迅速下降的主要原因是由光敏剂引发的光降解造成的,降解的主要产物为醛、酮、酸、酯和氧化物。经对真菌抗性试验表明,当聚乙烯的分子量降至５０００左右时,易被微生物侵蚀,即具有生物降解性。而塑膜中加入的改性淀粉起到加速这种侵蚀的作用。     

Characterization of tin dioxide film for chemical vapors sensor

Recently, oxide semiconductor material used as transducer has been the central topic of many studies for gas sensor. In this paper we investigated the characteristic of a thick film of tin dioxide (SnO₂) film for chemical vapor sensor. It has been prepared by screen-printing technology and deposited on alumina substrate provided with two gold electrodes. The morphology, the molecular composition and the electrical properties of this material have been characterized respectively by Atomic Force Spectroscopy (AFM), Fourier Transformed Infrared Spectroscopy (FTIR) and Impedance Spectroscopy (IS). The electrical properties showed a resistive behaviour of this material less than 300 °C which is the operating temperature of the sensor. The developed sensor can identify the nature of the detected gas, oxidizing or reducing.     

NiO_x电致变色薄膜结构与性能的X射线研究

电致变色是指材料的光学性能(光的透射、反射和吸收)通过外加电场或电流的作用,在包括可见光波长的某一波长范围内发生可逆变化的现象。氧化镍薄膜是目前发现的性能最好的电致变色材料之一,采用反应性磁控射频溅射法,利用金属镍作为靶材,在氮与氧混合气体中,通过直流磁控反应溅射法制备氧化镍薄膜,用X射线衍射技术分析其结构,用循环伏安法对NiOx薄膜的电致变色过程进行分析。     

Immobilization of carbon nanotubes on functionalized graphene film grown by chemical vapor deposition and characterization of the hybrid material

We report the surface functionalization of graphene films grown by chemical vapor deposition and fabrication of a hybrid material combining multi-walled carbon nanotubes and graphene (CNT–G). Amine-terminated self-assembled monolayers were prepared on graphene by the UV-modification of oxidized groups introduced onto the film surface. Amine-termination led to effective interaction with functionalized CNTs to assemble a CNT–G hybrid through covalent bonding. Characterization clearly showed no defects of the graphene film after the immobilization reaction with CNT. In addition, the hybrid graphene material revealed a distinctive CNT–G structure and p–n type electrical properties. The introduction of functional groups on the graphene film surface and fabrication of CNT–G hybrids with the present technique could provide an efficient, novel route to device fabrication.     

Thin film of carbon micro-spring forest

Carbon microcoils are generally prepared by catalytic chemical vapor deposition of acetylene, using Ni as the catalyst and thiophene as the promoter. In this work, Ni-sulphide has been used as a catalyst for the purpose of avoiding the introduction of noxious and unpleasant thiophene during the reaction process and getting the thin film of quasi-aligned carbon microcoils. SEM images show that the products obtained in the temperature range of 740-760 °C were pure, regular and had perfect morphology.     

Formation and characterization of Y : 247 film through spray pyrolysis technique

The synthesis of high temperature superconducting films of Y : 247 (T _c ～ 73 K) have been successfully achieved. The difficulty in synthesis owing to narrow range of stability of Y : 247 has been taken care of through several quenching modes, e.g. quenching of the films synthesized at ～850°C, in air or in liquid nitrogen. The energy dispersive analysis of X-rays (EDAX) and transmission electron microscopy (TEM) studies of the as processed film, Y₂Ba₄Cu₇O_14+x, exhibit nearly correct cationic stoichiometry of 2 :4 :7; also narrow regions (< 50 Å) of minority Y : 124 phase and stacking faults capable of working as flux pinning sites have been invariably found to be present. In addition to Y : 247, Ag admixed films have also been investigated. TheT _c here is ～ 70–75 K which is similar to that of the film without silver. Representative estimates of transport critical current density (J _c) for Y : 247 films is ～10³ A/cm², and with silver corresponding to Y₂Ba₄Cu₇O_14+x (Ag_0.1) is found to be ～ 10⁴ A/cm².     

Shallow bath chemical deposition of CdS thin film

Cadmium sulfide thin film was grown by shallow chemical bath deposition technique. This technique used a highly conducted hot plate to heat the substrate, while using a shallow bath for higher thermal gradients. As a result, large area uniformity could be achieved and the homogeneous nucleation was suppressed. More importantly, the solution used was greatly reduced, which is crucial for cost reduction in practice. The effects of temperature and shaking on the growth kinetics and film properties were investigated. The reaction activation energy was obtained to be 0.84 eV, and was not affected much by shaking indicating that the deposition is essentially reaction controlled. Furthermore, the films deposited at low or high temperature conditions had better photoconductivity.     

溅射气压和沉积时间对c-BN薄膜结构的影响

采用磁控反应溅射方法，在Si(100）衬底上沉积c-BN薄膜，研究了溅射气压和沉积时间对薄膜结构的影响。结果表明，随溅射气压的升高或沉积时间的增加，都是削弱荷能粒子对衬底表面的轰击效果，并导致薄膜中c-BN相含量的减小。     

Failure of pyrolysis coils coated with anit-coking film in an ethylene cracking plant

This paper presents a specific kind of failure in ethylene cracking coils coated with anti-coking film. It investigates a case in which the coils made of 35Cr 45Ni high temperature alloy failed within two years of operation. The damage occurred due to heavy oxidation in localized regions of the coil resulting in the formation of blisters, which eventually failed by cracking. The mechanism involved was determined by studying the oxidized samples under a scanning electron microscope with an energy dispersive system and is attributed to the presence of rare earth metals in the anti-coking film and inherent casting defects in the base alloy. The cerium present in the anti-coking film diffused preferentially to a defect site in the parent alloy thereby resulting in its segregation which further led to embrittlement.     

Nucleation and growth study of copper thin films on different substrates and wetting layers by metal-organic chemical vapour deposition

Chemical vapour deposition of copper thin films on different diffusion barrier/adhesion promoter layers have been studied. Copper thin films were grown in low pressure CVD reactor, using Cu(dpm)₂ as precursor and argon as carrier gas. Growth rates, film adhesion to the substrate, and surface morphology were studied in detail. Paper presented at the poster session of MRSI AGM VI, Kharagpur, 1995     

Infrared spectral study of the structure of oxyfluoroborate glasses

Glasses in the system (40 − x) CaF_2−x ZnO-60 B₂O₃ with x = 5, 10, 15, 20, 25, 30, 35 mol% are prepared by the melt quenching method. The structural changes in the glasses with the variation of ZnO content are studied by FTIR spectroscopy with special reference to structural units of borates. From the analysis of the deconvoluted IR spectra of the glasses the mechanism of the conversion and reconversion of BO₃ ↔ BO₄ units is explained using the concept of the borate structural units i.e., di-, tri-, tetra-, penta-, ortho-, pyro- and metaborates.