Papers

Papers:

(1) Fumed silica

1)Development and Analysis of Fumed Silica Standards

Authors: Wu Chunlei, Duan Xianjian, Wang Yuelin

Abstract: The basic content and scope of application of the national and international standards for fumed silica were reviewed, the differences between the standards were analyzed by comparing the key clauses of each standard, and the significance of their formulation was explored by reviewing the formulation and revision process of each standard.

2)Surface Modification of Fumed Silica

Authors: Wang Guangguo, Yang Benyi, Wang Yuelin

Abstract: The surface modification of fumed silica was introduced briefly in terms of the modification principles and processes, the use of common modifiers, and the application of modified fumed silica. The current development of the fumed silica industry in China was also discussed in the paper.

3)Effect of Fumed Silica on the Properties of HTV

Authors: Duan Xianjian, Liu Li, Liu Wenxiao

Abstract: The surface modification techniques of fumed silica were studied, and the properties of silica were characterized by the determination of the infrared spectrum, specific surface area, carbon content and methanol value. In addition, the effects of the specific surface area, surface modifiers and other factors of the fumed silica on the properties of heat vulcanized (HTV) silicone rubber were explored.

4)Effect of Fumed Silica Surface Modification on the Properties of Heat Vulcanized Silicone Rubber

Authors: Duan Xianjian, Shen Shihe, Wu Limin, Liu Wenxiao, Wang Weicheng

Abstract: The surface modification techniques of fumed silica were studied, and the properties of silica were characterized by the determination of the infrared spectrum, specific surface area, carbon content and methanol value. Finally, the effects of the specific surface area, surface modifiers and other factors of the fumed silica on the properties of heat vulcanized silicone rubber were explored.

5)Surface Modification of Silica and its Effect on the Heat Resistance of High Temperature Silicone Rubber

Authors: Wu Chunlei, Jiang Liyan, Liu Wenxiao, Duan Xianjian

Abstract: HMDS was used for the surface modification of fumed silica in this paper. The effect of the usage amount of fumed silica and its surface modification on the heat resistance property of high temperature silicone rubber was studied. The results show that the heat resistance of the high temperature silicone rubber is generally on the decline before it increases as the content of the unmodified fumed silica increases, indicating that a small amount of modified fumed silica can significantly improve the heat resistance of the high temperature silicone rubber. When the amount of the surface-modified fumed silica increases, however, its heat resistance decreases gradually, thereby revealing a rapid degradation trend in case of a higher amount of filling.

6)Research on the Thermal Stability of Silica-filled High Temperature Silicone Rubber

Authors: Wu Chunlei, Wang Yuelin

Abstract: The effects of the amount of fumed silica and its surface modification on the thermal stability of high temperature silicone rubber were studied in this paper. The results show that the heat resistance of the high temperature silicone rubber is on the decline before it increases as the content of the unmodified fumed silica increases, indicating that a small amount of modified fumed silica can significantly improve the heat resistance of the high temperature silicone rubber. When the amount increases, however, the heat resistance decreases gradually, thereby revealing a rapid degradation trend in case of a higher amount of filling.

7)Effect of Fumed Silicon on the Properties of Liquid Silicone Rubber

Authors: Wu Chunlei, Liu Wenxiao, Duan Xianjian

Abstract: The effects of the surface properties and the addition amount of fumed silica on the performance of liquid silicone rubber were studied in this paper. The results show that the fumed silica after surface treatment can significantly improve the light transmittance of the liquid silicone rubber filled with the fumed silica, of which the light transmittance and tensile strength increase gradually with the rise of hydrophobic degree. As the content of hydrophobic fumed silica increases, the tensile strength gradually elevates, whereas the light transmittance is on the decline after it continues going upward to the turning point.

8)Research on the Application of Fumed Silica in HTV

Authors: Chen Riwang, Liu Wenxiao, Wang Weicheng

Abstract: A continuous dry process was applied for the surface modification of fumed silica in this paper. The properties of the surface-modified fumed silica were characterized by the determination of infrared spectrum, specific surface area, carbon content and methanol value. Finally, the effects of the specific surface area, surface modifiers and other factors of the fumed silica on the properties of heat vulcanized (HTV) silicone rubber were explored.

9)Effect of Surface Modified Fumed Silica on the Properties of Liquid Silicone Rubber

Authors: Duan Xianjian, Wu Chunlei, Liu Wenxiao, Luo Yongliang

10)Application of Fumed Silica in Adhesives and Sealants and Potential Problems

Authors: Liu Jianyu, Wu Chunlei

Fumed silica (also known as SiO2) is one of the large-scale industrialized nanomaterials in the world. Fumed silica is characterized by a small particle size and a large specific surface area, and owing to the action of surface hydroxyl groups, the particles can aggregate to form a special three-dimensional network structure, endowing the substance with numerous excellent properties such as enhancement, thickening and thixotropy. Therefore, fumed silica has been widely used in silicone rubber, adhesives, paint inks, chemical mechanical polishing (CMP), medicine, cosmetics and other fields. This paper introduces the application of fumed silica in adhesives and sealants, and analyzes the potential problems that should be noticed in practical application.

11)Effects of Fumed Silica on the Properties of One-Component Silicone Sealants

Authors: Duan Xianjian, Wu Limin, Yang Benyi

Introduction: As early as the 1960s, one-component silicone sealants (hereinafter referred to as RTV-1) have been widely used in household and industrial applications as a multifunctional and versatile high-performance sealant. As a one-component system that cures at room temperature with moisture, RTV-1 has a series of superior properties, including good rheological and curing properties, excellent self-adhesion and transparency, as well as strong adaptability to extreme temperatures, weather conditions, ozone and chemicals. These outstanding properties are primarily associated with three factors in the RTV-1 system, namely a silicone polymer, a cross-linking system, and a reinforcing filler, whereas fumed silica is known as the most effective and versatile reinforcing filler. In this context, the paper focuses on the effects of various properties of fumed silica (including moisture content, specific surface area, amount, bulk density, etc.) on the performance of RTV-1.

12)The Production of Fumed Silica and its Application in the Polymer Industry

Authors: Sang Guoren, Wu Chunlei, Yang Benyi, Duan Xianjian

Abstract: The preparation mechanism of fumed silica was introduced in this paper. The production status and developing trend of fumed silica at home and abroad were analyzed, and the application of fumed silica in rubber, sealants, adhesives, plastics, thixotropic resin, gel coat resin, and coatings were outlined.

13)The Application of Fumed Silica in the Plastics Industry

Author: Wu Chunlei

Fumed silica (also known as SiO2) is one of the earliest and first industrialized nanoparticles. It is an amorphous high-purity white powder with a particle size between 7 to 40 mm and a specific surface area greater than 100 m2/g. SiO2 is usually prepared by the high-temperature hydrolysis of inorganic and organic silicon halides in water from a hydrogen-oxygen flame. At present, fumed silica is mainly produced by several foreign companies like Cabot, Degussa, Wacker and Nippon Aerosile due to the sophisticated preparation process, demanding technical requirements and strict control of related technologies by manufacturers. Upon years of research, development and innovation, China has basically mastered the key technologies for the production of fumed silica, which are mainly prepared by Shenyang Chemical Group, Shanghai Chlor-Alkali Factory, and Guangzhou GBS High-Tech & Industry Co., Ltd. Fumed silica is applicable to many fields, among which the application in the silicone rubber field has been studied at an earlier stage with more research findings and the most mature technology. Therefore, fumed silica is mainly applied as a reinforcing agent in silicone rubber. In the plastics industry, however, the application of fumed silica is relatively new, and has been rarely reported so far. Adding a small amount of fumed silica to plastics can obviously improve the density, rigidity and thermal stability of plastics, as well as maintain the transparency of plastic products. The sections below present a brief introduction to the application of fumed silica in the plastics industry.

14)Research Progress of Nano Silica Insulation Materials

Authors: Wu Chunlei, Yang Benyi, Liu Li, Kang Xu

Abstract: The types and basic characteristics of nano silica were described, and the research progress of the application of nano silica insulation materials was reviewed in the paper. The effects of relevant factors on the thermal insulation properties of insulation materials were analyzed. The future developing trend of nano silica insulation materials was also discussed.

15)Application of Highly Dispersed Fumed Silica in the Medical Field

Authors: Yang Benyi, Wu Chunlei, Duan Xianjian

Abstract: The properties and characteristics of fumed silica were briefly described, and its application in the medical field was discussed.

16)Research Progress of the Application of SiO2 in Flame Retarded Poly

Authors: Li Zhenhua, Wu Chunlei, Duan Xianjian, Li Zhengfa, Zhao Qianmin

Abstract: The research progress of the application of silica (SiO2) in flame retarded polymers was summarized in this paper. The flame retardancy mechanism of SiO2 and the effects of SiO2 on the flame retardancy, mechanical property and processing performance of polymers were reviewed. The synergistic effect of SiO2 with different types of flame retardants, and the effect of different forms of SiO2 on the properties of flame retarded polymers were also explored. The potential mechanism of preparing fumed SiO2-based flame retardants was discussed. Finally, the paper forecasts that halogen-free and environmentally friendly SiO2-based flame retardants will experience rapid development in the future.

17)Ultrafine Silica Matting Agent

Authors: Du Haijing, Wu Chunlei, Duan Xianjian, Chen Yanyu

Abstract: Ultrafine silica matting agents boast the advantages of easy dispersion, a small amount of addition, high chemical inertness, and good matting performance, etc. As an important matting product, it has been widely used in all kinds of matting coatings and materials. This paper reviews the types and preparation methods of synthetic ultrafine silica matting agents, and introduces the matting mechanisms, influencing factors of matting degree, and future directions for development.

（2）Fumed Alumina

①Preparation Methods and Application Prospects of Fumed Alumina

Authors: Chen Yanyu, Duan Xianjian, Wu Chunlei, Du Haijing

Abstract: The main preparation methods and current status of fumed alumina at home and abroad were summarized, the properties of fumed alumina and its applications in energy-saving lighting, spray paint, powder coatings, catalysis, ceramics, electronic information, composite materials, thermal insulation and other areas were introduced, and the market demands and development prospects of fumed alumina were also outlined.

②The Preparation of Fumed Alumina and its Application

Authors: Wang Guangguo, Yang Xiaochun, Duan Xianjian, Wu Chunlei

Abstract: The preparation theory, process control and industrial application of fumed alumina were introduced in this paper. The developing trend of fumed alumina was also summarized.

③The Preparation of Fumed Alumina and its Application in Energy Saving Lamps

Authors: Wu Chunlei, Liu Li, Yang Benyi, Kang Xu

Abstract: The preparation process and properties of fumed alumina were introduced, the research progress of its application in energy-saving lamps was reviewed, and its future development was elaborated.