On the basis of microgravimetric sensing data, an analytical modeling method is proposed for comprehensive evaluation and optimization of gas sensing or adsorbing related functional materials. Resonant microcantilever is loaded with the material to be evaluated for a gravimetric sensing experiment. With sensing isotherm curves obtained at different temperatures, key thermodynamic and kinetic parameters of the material, such as enthalpy ΔH°, Gibbs free energy, adsorption rate constant Ka, and coverage θ, etc., can be quantitatively extracted for optimal selection and design. On the basis of the gravimetric experiment, the modeling method is used on three sorts of trimethylamine sensing nanomaterials of mesoporous silica nanoparticles (MSNs). The COOH-functionalized material is clearly identified as the best sensing material among the three similar ones, thereby validating high accuracy of the proposed model. Broad applicability of the modeling method to other sensing materials and/or target gases is also experimentally confirmed, where sensing properties of a functionalized hyper-branched polymer to organophorous simulant of dimethyl methylphosphonate (DMMP) are still evaluated well. In addition to sensing materials, the gravimetric experiment-based modeling method can be expanded to other functional materials like moisture absorbents or detoxification agents. Water adsorbing experiment on KIT-5 mesoporous-silica is modeled, with the low -ΔH° value (i.e., low adsorption heat) result, indicating that the KIT-5 is a good adsorbent to humidity. Alternatively, the modeled high -ΔH° value (i.e., high reaction heat) shows promising usage of SBA-15 mesoporous-silica as detoxification material to hazardous organophorous chemicals. Therefore, the analytical modeling technology can be used for developing and evaluating new adsorbing materials for gas sensing, fixing, and detoxification applications.

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.