Microstructure and properties of nc-TiC/a-C∶H films deposited by radio frequency reactive sputtering

Abstract

Amorphous carbon films containing titanium carbide (nc-TiC/a-C∶H) were deposited onto n-type silicon (100) by radio frequency reactive sputtering titanium target in an Ar–CH₄ mixed atmosphere. The composition and microstructure of the films were characterised by means of X-ray photoelectron spectroscopy, field emitted SEM, XRD and Raman spectra. The mechanical and tribological properties of the films were measured by a nanoindentation tester and a ball-on-disc UMT–2MT tribometer. By adjusting the CH₄ flowrate, Ti content in the films could be controlled, and a transition in structures of the films from loose polymer-like to glassy and dense nanostructure was observed. The density of coatings was improved by the introduction of TiC nanocrystalline particles. The mechanical and lubricious properties were different accordingly.     

250℃下时间效应对PAN纤维热氧稳定化反应的影响及关联

借用傅里叶变换红外光谱(FT-IR)、元素分析(EA)、X射线衍射(XRD)和示差扫描量热分析(DSC)等手段,对比研究了热氧稳定化过程中250℃下时间效应与两种聚丙烯腈(PAN)共聚纤维及其炭纤维结构和性能之间的关联。研究结果表明,PAN纤维在250℃温区内停留超过9min时,最终热氧稳定化纤维的环化度(RCI)、体密度和芳构化指数(AI)的增加速率开始变小;炭纤维的孔含量(Vp)值与内部微晶的d002值开始增大,微晶排列的规整程度变差,缺陷增多,拉伸强度开始降低。     

还原剂和水蒸汽对钯催化NO还原反应性能的影响

为满足严格的排放法规,在控制好NOx排放的同时,也需减少N2O、NH3等二次污染物的排放。为探究尾气组分对NOx还原产物的影响,本文用催化活性模拟评价装置,对自制单钯三效催化剂,进行了还原剂种类、CO浓度及水蒸汽浓度对NO转化效率及N2O和NH3生成产物的影响研究。结果表明,CO催化还原NO是导致N2O生成的主要原因,其内在本质在于催化剂表面活性氧物种的协同作用,NH3的生成量在150~400 ℃范围内与反应温度正相关;水蒸汽的加入会促进N2O和NH3的生成,H2O分子在催化剂表面吸附作用抑制了活性氧物种的消耗;增加CO浓度可抑制N2O生成但会促进NH3生成。     

负载氧化锌活性炭对苯的吸附性能及热力学研究

对微波活化处理废触媒制备的活性炭进行了微结构分析,发现活性炭具有孔隙发达,微孔贯穿性好的结构,孔隙中负载了少量的具有催化作用的氧化锌.采用光离子化气相色谱法测定了20℃、30℃和40℃活性炭对苯的吸附等温线,并用Langmuir方程进行了数据拟合,且适合于该方程.同时计算了平均吸附热(△H),吸附自由能(△G),吸附熵...     

Metal–Organic Gel‐Derived FexOy/Nitrogen‐Doped Carbon Films for Enhanced Lithium Storage

The development of cost‐effective and flexible electrodes is demanding in the field of energy storage. Herein, flexible Fe_xO_y/nitrogen‐doped carbon films (Fe_xO_y/NC‐MOG) are prepared by facile electrospinning of Fe‐based metal–organic gels (MOGs) followed by high‐temperature carbonization. This approach allows the even mixing of fragile coordination polymers with polyacrylonitrile into flexible films while reserving the structural characteristics of coordination polymers. After thermal treatment, Fe_xO_y/NC‐MOG films possess uniformly distributed Fe_xO_y nanoparticles and larger accessible surface areas than traditional Fe_xO_y‐NC films without MOG. Taking advantage of the unique structure, Fe_xO_y/NC‐MOG exhibits a superior rate performance (449.8 mA h g^?1 at 5000 mA g^–1) and long cycle life (629.3 mA h g^–1 after 500 cycles at 1000 mA g^–1) when used as additive‐free anodes in lithium‐ion batteries.     

无机纳米抗菌剂及其载体

综述了无机纳米抗菌剂及其载体的最近研究进展。无机纳米抗菌剂主要包括光催化型和金属型,抗菌剂载体主要有沸石、二氧化硅、磷酸盐系、壳聚糖、脂质体和聚合物等。具体介绍了金属型和光催化型这两类无机纳米抗菌剂的抗菌机理、抗菌特性及研究现状等,并概述了当下无机纳米抗菌剂载体的主要种类和特点,同时对无机纳米抗菌剂的研究方向进行了展望...     

改性聚偏氟乙烯接枝苯乙烯/丙烯酸磺酸电解质膜及其在CO传感器中的应用

以过氧化苯甲酰(BPO)作引发剂,通过溶液接枝聚合法把苯乙烯/丙烯酸同时接枝到原硅酸钠改性的聚偏氟乙烯(PVDF)膜上,磺化后得到聚偏氟乙烯接枝苯乙烯/丙烯酸磺酸(PVDF-g-PS/ PASA)膜.FTIR分析表明:苯乙烯和丙烯酸接枝到PVDF膜上;环境的相对湿度在20%～80%范围内,对PVDF-g-PS/ PASA膜电导率的影响基本不变,并达到0.0198S·cm-1,40℃保水率达99%.将膜应用于CO传感器中,传感器电流响应信号与CO气体浓度具有较好的线性关系.     

表面化学改性活性炭在水处理中的应用

介绍表面化学改性活性炭研究进展,针对其特点和改性方法作了系统描述.在此基础上,对其去除水中有机物、重金属离子、亚硝酸盐等污染物质做了简要说明.