摘要
以Na_(2)SiO_(3)·5H_(2)O和MgCl_(2)·6H_(2)O为原料,采用沉淀法制备高比表面积羟基硅酸镁,利用X射线衍射、扫描电镜、BET比表面积测试等检测手段,研究硅镁比、体系pH值、反应时间、反应温度、煅烧或水热处理对产物物相结构、微观形貌和比表面积的影响。结果表明:硅镁比为3∶1、体系pH值为10±0.05、反应时间为80min、反应温度为75℃时制得比表面积为263.37m^(2)/g的羟基硅酸镁;经7h水热处理,所得羟基硅酸镁比表面积增加至425.30m^(2)/g,提高了61.48%;羟基硅酸镁是由[SiO_(4)]四面体、[MgO_(6)]八面体及羟基形成的三层状结构,其孔道由层状结构堆叠交错而形成;溶液中的OH^(-)可为Si—O—Mg—OH基团和硅烷醇基团(Si—O—H)的形成提供羟基,有助于提高羟基硅酸镁表面活性和比表面积。
Hydroxyl magnesium silicate as a high specific surface area material,was synthesized by precipitation reaction from sodium silicate pentahydrate(Na_(2)SiO_(3)·5 H_(2)O),magnesium chloride hexahydrate(MgCl_(2)·6 H_(2)O)and deionized water.The influences of the ratio of silicon to magnesium,pH value,reaction temperature,reaction time,calcination treatment or hydrothermal on the phase composition,morphology and specific surface area of the obtained hydroxy magnesium silicate were investigated by XRD,SEM and BET.Results showed that when the ratio of Si to Mg was 3∶1,the pH value of the reaction system was 10±0.05,reaction temperature was 75℃,reaction time was 80 min,the hydroxy magnesium silicate with a specific surface area of 263.37 m^(2)/g was prepared.After hydrothermal treatment for 7 hours,the specific surface area of the hydroxy magnesium silicate increased to 425.30 m^(2)/g was prepared.After hydrothermal treatment for 7 hours,the specific surface area of the hydroxy magnesium silicate increased to 425.30 m^(2)/g,making an increase of 61.48%.The channels are formed by stacking and interlacing layered structures.Hydroxy magnesium silicate is a three-layer structure formed by[SiO_(4)]tetrahedron,[MgO_(6)]octahedron and hydroxyl group;the Si-O-Mg-OH groups and silanol group(Si-O-H)can be constructed by OH^(-)providing hydroxyl groups in solution,which is helpful to increase the surface activity and the specific surface area of hydroxy magnesium silicate.
作者
王琪浩
王余莲
王楠
李闯
张俊
朱益斌
刘珈伊
时天骄
林永瑾
田伊笛
苏德生
袁志刚
WANG Qihao;WANG Yulian;WANG Nan;LI Chuang;ZHANG Jun;ZHU Yibin;LIU Jiayi;SHI Tianjiao;LIN Yongjin;TIAN Yidi;SU Desheng;YUAN Zhigang(Shenyang Ligong University,Shenyang 110159,China;School of Materials Science and Engineering,Taiyuan University of Technology,Taiyuan 030024,China;Liaoning Province Ultrahigh Power Graphite Electrode Material Professional Technology Innovation Center,Dandong 118100,China)
出处
《沈阳理工大学学报》
CAS
2022年第6期58-65,共8页
Journal of Shenyang Ligong University
基金
国家自然科学基金青年科学基金项目(51804200)
沈阳理工大学大学生创新创业训练计划项目(202110144113)。
关键词
羟基硅酸镁
沉淀法
比表面积
形成机理
hydroxy magnesium silicate
precipitation method
specific surface area
formation mechanism
