Study of mechanical properties of moisture-saturated silica gel granules

The feasibility of mechanical testing of soft, water-saturated silica gel granules using the commercially available NanoScan-4D nanohardness tester was demonstrated. A method for determining the strength and elastic properties of silica gel granules under compression by flat punches was developed and tested. Load ranges reliably causing specimen failure were experimentally established. An analysis of the loading diagrams obtained during testing allowed for determining the elastic modulus and estimating the adhesion forces between the silica gel and punch surfaces. A fatigue testing method for granules at the resonant frequency of the nanohardness tester’s mechanical system is proposed, enabling the evaluation of mechanical property degradation under cyclic loading. The research results confirm the applicability of the nanomechanical approach for quantitatively assessing the strength properties, elastic modulus, and adhesion characteristics of hydrated porous materials. The proposed method can be used in the development and optimization of silica gel adsorbents, catalyst carriers and composite materials operated under conditions of cyclic loads, variable humidity and temperature.