#Silica in water free

Daiguji, “ A review of solid desiccant dehumidifiers: Current status and near-term development goals in the context of net zero energy buildings,” Renewable Sustainable Energy Rev. A recent approach suggests a possible use of silica nanopores as more efficient desiccant dehumidifiers, in which water is trapped in the nanopore as a liquid. Besides being the precursor of glass and silicon, more recent applications of silica include fillers, catalysts, and catalyst supports, and one of the most common products is silica gel, which, nowadays, spreads as a desiccant for industrialized food, making use of its efficient interaction with water. Silica (SiO 2) is a common substance found in nature, in particular, in the sand, and used since ancient times for the production of glass. Relations between work of adhesion, interfacial energy, and entropy loss were also analyzed, and their influence on the wettability was discussed. On partially hydroxylated surfaces, in which θ YD and θ app slightly deviated, the Brownian motion of the droplet was suppressed, possibly due to the pinning of the contact line around the hydroxyl groups. The theoretical contact angle θ YD and the apparent one θ app, both indicating the enhancement of wettability by an increase in ρ A O H, presented good quantitative agreement, especially for non-hydroxylated and highly hydroxylated surfaces.

#Silica in water free

For the former, the work of adhesion needed to quasi-statically strip the water film off the solid surface was computed by the phantom wall TI scheme to evaluate the SL interfacial free energy, whereas for the latter, the apparent contact angle θ app was calculated from the droplet density distribution. In the present work, we examined the wetting of water on neutral and regular hydroxylated silica surfaces with five different area densities of OH groups ρ A OH, ranging from a non-hydroxylated surface to a fully hydroxylated one through two theoretical methods: thermodynamic integration (TI) and MD simulations of quasi-two-dimensional equilibrium droplets. Molecular dynamics (MD) simulation is one of the powerful tools for microscopic analysis providing visual images and mean geometrical shapes of the contact line, e.g., of nanoscale droplets on solid surfaces, while profound understanding of wetting demands quantitative evaluation of the solid–liquid (SL) interfacial tension. In the last few years, much attention has been devoted to the control of the wettability properties of surfaces modified with functional groups.