State Key Laboratory of Transducer Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, 865 Changning Road, Shanghai, 200050, China.
Small. 2014 Jun 25;10(12):2404-12. doi: 10.1002/smll.201303633. Epub 2014 Mar 4.
The study reports the effect of mesoporous silica nanoparticles (MSNs) on detoxification of toxic organophorous compounds. Based on gravimetric sensing experiment with resonant microcantilever, rapid adsorption of the organophorous simulant of dimethyl methylphosphonate (DMMP) onto MSNs is confirmed. The experimentally observed irreversible gravimetric-signal implies that substitution-reaction possibly occurs at the nanomaterial surface. By exploring a method of gravimetric detection at different temperatures to obtain two isotherms, high reaction-heat of 97.1 kJ mol(-1) is extracted that indicates strong chemical interaction. Characterizations with solid-state NMR and FT-IR to the MSNs are performed during the adsorption/interaction process, revealing that substitution-reaction exactly occurs. GC-MS analysis to the post-reaction vapor exhaust indicates that one or two methyl groups in a DMMP molecule can be substituted by hydrogen atom(s) through substitution-reaction with silanol group(s) of MSNs, thereby, destructing DMMP into two sorts of new molecules. With such comprehensive analyses, the destruction/detoxification mechanism is clearly identified. To evaluate the detoxification performance of the MSNs, real toxic of dichlorvos is experimentally examined, resulting in that organophosphate dichlorvos is detoxified into non-toxic dimethylphosphate. The low-cost and producible MSNs are promising for detoxification to organophorous compounds. Besides, the micro-gravimetric analysis method can be expanding for extensive researches on various functional materials.
该研究报告了介孔硅纳米粒子（MSNs）对解毒有毒有机磷化合物的影响。基于共振微悬臂的重量感应实验，确认了有机磷模拟物二甲基甲基膦酸酯（DMMP）迅速吸附到 MSNs 上。实验观察到的不可逆重量信号表明，可能在纳米材料表面发生取代反应。通过探索在不同温度下进行重量检测的方法获得两个等温线，提取出 97.1 kJ mol(-1) 的高反应热，表明存在强烈的化学相互作用。在吸附/相互作用过程中对 MSNs 进行固态 NMR 和 FT-IR 表征，表明确实发生了取代反应。对反应后蒸汽排放物进行 GC-MS 分析表明，DMMP 分子中的一个或两个甲基可以通过与 MSNs 的硅醇基团发生取代反应被氢原子取代，从而将 DMMP 破坏成两种新分子。通过这种综合分析，明确了破坏/解毒机制。为了评估 MSNs 的解毒性能，实验检验了真实有毒的敌敌畏，结果表明有机磷敌敌畏被解毒为无毒的磷酸二甲酯。低成本和可生产的 MSNs 有望用于解毒有机磷化合物。此外，微重量分析方法可以扩展到各种功能材料的广泛研究中。
