Surface modification of TiO2 nanoparticles with terephthalic acid in supercritical carbon dioxide
Surface modification of TiO2 nanoparticles with terephthalic acid in supercritical carbon dioxide
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DOI：
10.1016/j.supflu.2021.105245
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发表时间：
2021-04
期刊：
影响因子：
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通讯作者：
Anggi Regiana Agustin;K. Tamura
中科院分区：
文献类型：
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作者：
Anggi Regiana Agustin;K. Tamura
TiO2 纳米颗粒的表面需要进行改性，以防止团聚过程并确保它们在应用系统中完美分散。本论文提出了一种用二羧酸对 TiO2 纳米粒子进行表面修饰的超临界 CO2 策略。为了获得最佳的改性率，通过改变工艺压力、温度和改性剂的重量比来检查工艺条件。采用 Box-Behnken 实验设计和响应面统计方法来确定最佳工艺条件。通过 FTIR、TG-DTA、FE-SEM、TEM-EDS 和 zeta 电位分析对改性 TiO2 进行了表征，并与未改性的 TiO2 纳米颗粒进行了比较。结果表明，sc-CO2中TiO2的表面改性是由改性剂分子以双齿螯合和桥联形式化学键合而成。 TiO2纳米颗粒与二羧酸分子在sc-CO2中反应，得到羧酸改性的TiO2纳米颗粒，其改性效率远高于传统的溶剂浸泡方法。对苯二甲酸和对氨基苯甲酸的表面改性影响了水中 TiO2 纳米颗粒的表面电性能，导致表面带正电荷。由于该方法生态环保，因此可应用于多种材料的合成。
The surface of TiO2 nanoparticles needs to be modified to prevent the agglomerations process and ensure they have perfect dispersion in the applied system. This thesis presents a supercritical CO2 strategy for surface modification of TiO2 nanoparticles with dicarboxylic acids. To obtain an optimum modification rate, process conditions were examined by changing the process pressure, temperature, and weight ratio of the modifier. A Box-Behnken experimental design and a statistical method of response surface methodology was carried out to determine optimum process conditions. The modified TiO2 was characterized by FTIR, TG-DTA, FE-SEM, TEM-EDS, and zeta potential analysis and compared to unmodified TiO2 NPs. The results showed the surface modification of TiO2 in sc-CO2 is made of modifier molecules bonding chemically in form of bidentate chelating and bridging mode. The reaction between TiO2 nanoparticles and dicarboxylic acid molecules in sc-CO2 provides carboxylic acid-modified TiO2 nanoparticles with a modification efficiency much higher than the conventional solvent immersion method. Surface modification by terephthalic acid and para-aminobenzoic acid affects the surface electrical property of TiO2 nanoparticles in water, leading to a positive charge surface. Since this method is ecologically and environmentally friendly, it can be applied in the synthesis of materials for many applications.