Controllable synthesis of uniform small-sized MgCO_(3) from Mg^(2+) concentrated seawater brine for the preparation of epoxy resin composite and high purity MgO  

作　　者：Shuo Yan Hongfei Guo Dapeng Zhang Yun Li Jilin Cao 

机构地区：[1]Engineering Research Center of Seawater Utilization Technology of Ministry of Education,School of Chemical Engineering and Technology,Hebei University of Technology,Tianjin,300401,China

出　　处：《Particuology》2025年第2期154-166,共13页颗粒学报(英文版)

基　　金：We are grateful for the financial support from the National Natural Science Foundation of China(grant Nos.22478095 and 22008049);Key Research and Development Project of Hebei Province,China(grant No.22374101D).

摘　　要：The large and uneven grain size of anhydrous magnesium carbonate (MgCO_(3)) seriously restricts its application ranges and performances. In this study, we proposed a controllable and cost-effective strategy to synthesize uniform small-sized MgCO_(3) from Mg^(2+) concentrated seawater brine in the absence of crystal modifiers. In this process, solid NaOH was directly added to Mg^(2+) concentrated seawater brine to completely and rapidly convert Mg^(2+) to magnesium hydroxide (Mg(OH)_(2)) nanoparticles. These nanoparticles are redispersed in water to form the colloidal system, where Mg(OH)_(2) nanoparticles hydrothermally reacts with urea to obtain uniform small-sized MgCO_(3) particles. The influence of reaction temperature, reaction time, and the molar ratio of magnesium ions to urea on the synthesis of MgCO_(3) is systematically investigated. In the highly-dispersed and stable colloidal system, Mg(OH)2 nanoparticles could exert an effective and sustained retarding effect on the hydrolysis rate of urea by attracting free water, resulting in the controllable release of NH_(4)^(+), CO_(3)^(2−), and Mg^(2+). This study presents a simple route to realize the controllable synthesis of uniform small-sized MgCO_(3) particles, and demonstrates the feasibility of using MgCO_(3) as an ideal filler for enhancing the performance of polymers as well as an ideal precursor for high-purity MgO production.

关 键 词：Uniform small-sized MgCO_(3) Mg(OH)_(2)nanoparticles Mg^(2+)concentrated seawater brine Flame retardant High-purity Mgo 

分 类 号：O62[理学—有机化学]