Agaba Aphra, Cheng Huan, Zhao Jiangbin, Zhang Congcong, Tebyetekerwa Mike, Rong Liduo, Sui Xiaofeng, Wang Bijia
Key Lab of Science and Technology of Eco-textile, Ministry of Education, College of Chemistry, Chemical Engineering and Biotechnology, Donghua University Shanghai 201620 People's Republic of China
Research School of Engineering, College of Engineering and Computer Science, The Australian National University Canberra Australian Capital Territory 2601 Australia.
RSC Adv. 2018 Sep 25;8(58):33129-33137. doi: 10.1039/c8ra05611k. eCollection 2018 Sep 24.
Silicon-containing compounds such as silica are effective heavy metal sorbents which can be employed in many applications. This is attributed to the porous nature of hydrothermally-stable silica, endowing such materials with high surface area and rich surface chemistry, all responsible for improving adsorption and desorption performance. However, to this day, the wide application of silica is limited by its skeletal brittleness and high production cost coupled with a risky traditional supercritical drying method. To solve the named problems, herein, precipitated silica agglomerates (referred to as PSA) was crosslinked with TEMPO-oxidized cellulose nanofibrils (TO-CNF) as a reinforcement in the presence of 3-aminopropyltriethoxysilane (APTES), a facile dual metal synthesis approach, is reported. The resultant new silica-based sponges (TO-CNF PSA) showed desirable properties of flexibility, porosity and multifaceted sorption of various heavy metals with re-usability. The experimental results showed maximum adsorption capacities of 157.7, 33.22, 140.3 and 130.5 mg g for Pb(ii), Hg(ii), Cr(iii) and Cd(ii) ions, respectively. Such a facile approach to modify silica materials by attaching active groups together with reinforcement can provide improved and reliable silica-based materials which can be applied in water treatment, gas purification, thermal insulation .
含硅化合物（如二氧化硅）是有效的重金属吸附剂，可用于许多应用中。这归因于水热稳定二氧化硅的多孔性质，赋予此类材料高比表面积和丰富的表面化学性质，所有这些都有助于提高吸附和解吸性能。然而，时至今日，二氧化硅的广泛应用受到其骨架脆性、高生产成本以及传统超临界干燥方法风险的限制。为了解决上述问题，本文报道了一种简便的双金属合成方法，即在3-氨丙基三乙氧基硅烷（APTES）存在下，将沉淀二氧化硅团聚体（称为PSA）与氧化纤维素纳米纤维（TO-CNF）交联作为增强材料。所得新型二氧化硅基海绵（TO-CNF PSA）表现出理想的柔韧性、孔隙率以及对各种重金属的多方面吸附和可重复使用性。实验结果表明，对Pb(ii)、Hg(ii)、Cr(iii)和Cd(ii)离子的最大吸附容量分别为157.7、33.22、140.3和130.5 mg/g。这种通过连接活性基团和增强材料来改性二氧化硅材料的简便方法可以提供性能改进且可靠的二氧化硅基材料，可应用于水处理、气体净化、隔热等领域。
