Optimized microwave-assisted functionalization and quantification of superficial amino groups on porous silicon nanostructured microparticles

This work presents an optimized microwave (MW)-assisted method for the chemical functionalization of porous silicon particles (PSip). 3-(Aminopropyl)triethoxysilane (APTES) was grafted on previously stabilized PSip. The functionalization efficiency was studied and optimized in terms of reaction time (Rt) and reaction temperature (RT) using a central composite design (CCD). The effect of MW irradiation on the surface coverage was found to strongly depend on the PSip surface chemistry, Rt, RT, and percentage of APTES. Quantification of grafted amino groups was performed by the ninhydrin method (NHIM); confirming the results by thermogravimetric analysis (TGA). Reacting with 5% APTES solution at 95 degrees C for 26 min was the best functionalization conditions. The efficiency of PSip-APTES prepared under the optimized conditions was compared to those functionalized by the traditional method; MW irradiation increases by 39% the number of functional groups grafted onto the PSip surfaces with the additional benefit of having a drastic reduction in Rt.

Automated summary

An optimized microwave-assisted method for chemical functionalization of porous silicon particles was proposed in this study, showing improved efficiency and reduced reaction time. The impact of microwave irradiation on surface coverage was found to be dependent on various factors, including the surface chemistry of PSip and reaction conditions.