自干型有机硅耐烧蚀涂料制备及性能研究

针对室外露天使用的大型高温燃烧炉设备的表面防护,研制一种能够室温自干的有机硅耐烧蚀涂料。以特种环氧改性有机硅树脂作为成膜树脂,复配可熔融陶瓷粉、金属粉、耐高温填料制备有机硅耐烧蚀涂料。结果表明,所制备涂料适合在户外大面积施工应用,能在室温条件下自然干燥,无需高温加热固化,具有优异的耐热性与耐烧蚀性,可在500℃高温环境下长时间使用,可短时承受1000℃高温火焰烧蚀,并展现良好的耐中性盐雾与耐湿热性能,满足在室外大型高温燃烧炉设备表面施工与应用要求。     

SiC薄膜的阻氚性能研究

在不锈钢基体表面用离子束混合技术沉积SiC薄膜,然后用能量为5 keV的H+对其辐照直至剂量达到1×1018/cm2,再用二次离子质谱分析(SIMS)分析H+在SiC薄膜中深度分布和正离子谱,研究薄膜的阻氢性能和阻氢机理;最后采用渗透实验对涂覆在不锈钢基体表面的SiC材料的氚渗透系数进行测试,对其阻氚性能进行验证.结果表明,在不锈钢基材表面涂覆的SiC薄膜具有良好的阻氢性能,可将氚的渗透率降低4个数量级以上,SiC薄膜的阻氢是由于氢与薄膜中的硅、碳悬挂键反应形成诸如C-H、C-H2、C-H3、Si-H、Si-H2和Si-H3引起的.     

多弧离子镀与磁控溅射共沉积TiN/TiCN多层膜的高温抗氧化性能

TiN/TiCN多层膜的高温抗氧化性研究对于扩大其应用领域具有重要作用,但目前鲜见相关报道。采用多弧离子镀与磁控溅射技术以不同调制周期在304不锈钢表面共沉积TiN/TiCN多层膜。采用XRD、XPS、倒置显微镜及高温氧化试验研究了多层膜的高温抗氧化行为。结果表明:TiN/TiCN多层膜表面光滑平整、均匀致密,薄膜主要为具有Ti-(C,N)键的fcc-TiN结构;随着调制周期的减小,TiN/TiCN多层膜生长取向发生转变,且具有(111)晶面生长织构;随着氧化温度的升高,多层膜的显微硬度逐渐降低,氧化增重速率不断增大,且在700℃之后变化速率较快,薄膜的开始氧化温度约为750℃;随着调制周期的减小,多层膜TiN与TiCN界面层数量增多,促使晶粒细化,提高了其致密性,还隔断了缺陷贯穿薄膜的连续性,显著降低了薄膜的孔隙率,致使O原子扩散困难,增强了薄膜的高温抗氧化性能。     

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.     

国内外环氧树脂的生产现状及应用进展

本文阐述国内外环氧树脂发展动向及应用进展。     

Investigation of temperature-dependent polarization, dielectric, and magnetization behavior of multiferroic layered nanostructure

The PbZr_0.53Ti_0.47O₃(PZT)/CoFe₂O₄(CFO) layered nanostructures show lowering of dielectric constant and polarization, and an enhanced magnetization with a decrease in temperature from 400 K to 100 K. The temperature dependence of the real part of the dielectric constant illustrates a step-like behavior, whereas the imaginary part gives a relaxation peak near the step maxima temperature. A slow decrease in the polarization was observed from 300 K to 200 K, with an eventual collapse of polarization at ~ 100 K, and a complete polarization recovery with heating, these phenomena is reproducible over cycles of experiment. Remanent magnetization of the layered nanostructure was found to be three times higher at 100 K than that at room temperature. There is a slow enhancement in remanent (internal) magnetization with lowering of temperature, resulting in slow polarization switch and finally the collapse. The temperature-dependent dielectric, polarization and magnetization were different from the parent layer, indicating a kind of dynamic magneto-electric coupling in the layered nanostructures.     

Biomimetic Robust Starch Composite Films with Super-Hydrophobicity and Vivid Structural Colors

The starch composite films (SCFs) will be one of the best alternative packaging materials to petroleum based plastic films, which mitigates white pollution and energy consumption. However, weak mechanical stability, water resistance, and dyeability has hindered the application of SCFs. Herein, a bioinspired robust SCFs with super-hydrophobicity and excellent structural colors were prepared by fiber-reinforcement and assembling SiO₂/Polydimethylsiloxane (PDMS) amorphous arrays on the surface of SCFs. The properties of the designed SCFs were investigated by various methods including scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), thermo-gravimetric analysis (TGA), a tensile test, contact angle (CA) test, and an optical test. The results showed that the obtained SCFs possessed a higher tensile strength (55.17 MPa) attributed to the formed abundant hydrogen bonds between the molecular chains of the starch, cellulose fiber, and polyvinyl alcohol. Benefiting from the nanostructure with rough surface which were modified by materials with low surface free energy, the contact angle and sliding angle of the film reached up to 154° and 2°, respectively. The colors which were produced by the constructive interference of the coherent scattered light could cover all of the visible regions by tuning the diameters of the SiO₂ nanoparticles. The strategy in the present study not only reinforces the mechanical strength and water resistance of SCFs but also provides an environmentally friendly way to color the them, which shows unprecedented application potential in packaging materials of the starch composite films.     

用磁控溅射法制备的Ag-MgF2的复合薄膜的研究

采用RF磁控溅射方法制备了Ag-MgF2复合薄膜.通过XRD测量,发现当退火温度在300～500℃时,Ag以晶态形式镶嵌在非晶态介质中;当退火温度低于300℃时候,Ag以非晶态形式存在.在分层镀Ag和MgF2薄膜后,经过热处理使Ag颗粒扩散在MgF2介质中,通过AFM观察,对复合薄膜形貌进行了分析:如果先镀MgF2薄膜,再镀Ag薄膜,发现Ag颗粒主要分布在薄膜的表面,并且富集形成较大的颗粒,表现出块体Ag的吸收特性.而先镀Ag薄膜,然后再镀MgF2薄膜,经过热处理,可以形成Ag颗粒均匀镶嵌在介质中形成的复合薄膜.同时对样品的吸收特性也进行了研究.     

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.