Mesoporous Silica Nanoparticles (MSNs) for Detoxification of Hazardous Organophorous Chemicals

Abstract

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.

High thermostable ordered mesoporous SiO2–TiO2 coated circulating-bed biofilm reactor for unpredictable photocatalytic and biocatalytic performance

“…The FT-IR spectrum of the SiO 2 -TiO 2 is used to investigate the composition and structure of the resultant samples [38][39][40]. As shown in Fig.…”

Hyper-branch sensing polymer batch self-assembled on resonant micro-cantilevers with a coupling-reaction route

“…Although some special coating techniques like ink-jet spotting and tiny-capillary incubation under optical microscope have been used, manual loading is really a difficult task to secure uniform sensing performance within a whole run of fabricated sensors [13,[19][20][21][22]. In our lab, a commercially available micro-manipulator equipped with a labmade capillary is employed to load the sensing material onto the desired micro-region of the cantilever [23][24][25][26][27][28][29]. With the help of this special tool, various sensing materials like functionalized mesoporous silica, sensing polymer and Au-NPs/grapheme-oxide hybrid have been precisely coated onto resonant cantilevers to construct high-sensitivity gas sensors [23][24][25][26][27][28][29].…”

“…In our lab, a commercially available micro-manipulator equipped with a labmade capillary is employed to load the sensing material onto the desired micro-region of the cantilever [23][24][25][26][27][28][29]. With the help of this special tool, various sensing materials like functionalized mesoporous silica, sensing polymer and Au-NPs/grapheme-oxide hybrid have been precisely coated onto resonant cantilevers to construct high-sensitivity gas sensors [23][24][25][26][27][28][29]. Unfortunately, such an approach is still a one-by-one method that suffers from several drawbacks like time-consuming, labor-intensive, inconsistent and irreproducible.…”

Quantitatively extracted Gibbs free-energy (ΔG) as criterion to determine working temperature range of gas sensing-material

“…It is known that adsorbing-type materials tend to spontaneously adsorb molecules to lower the surface-energy, and the adsorbed molecule amount will decrease with temperature increasing [1]. When the temperature reaches a certain limit, adsorption will stop.…”

“…The previous reports indicated that silica with ≡Si-OH covered on its surface is sensitive to DMMP-vapor (dimethyl-methylphosphonate, a simulant for toxic organophosphorus-agents) [1][2][3]. Based on the adsorption between mesoporous silica nanoparticles (MSNs) and organophosphorus, MSNs shows potential for developed as toxic organophosphorus detoxification materials.…”