Synthesis of microporous silica nanoparticles to study water phase transitions by vibrational spectroscopy

Silica can take many forms, and its interaction with water can change dramatically at the interface. Silica based systems offer a rich tapestry to probe the confinement of water as size and volume can be controlled by various templating strategies and synthetic procedures. To this end, microporous silica nanoparticles have been developed by a reverse microemulsion method utilizing zinc nanoclusters encapsulated in hydroxyl-terminated polyamidoamine (PAMAM-OH) dendrimers as a soft template. These nanoparticles were made tunable within the outer diameter range of 20-50 nm with a core mesopore of 2-15 nm. Synthesized nanoparticles were used to study the effects of surface area and microporous volumes on the vibrational spectroscopy of water. These spectra reveal contributions from bulk interfacial/interparticle water, ice-like surface water, liquid-like water, and hydrated silica surfaces suggesting that microporous silica nanoparticles allow a way to probe silica water interactions at the molecular scale

Density and viscosity for a binary mixture of ethyl 2-methyl butyrate, ethyl hexanoate with methanol, ethanol and 1-propanol at (293.15, 303.15, 313.15) K

The density and viscosity of binary mixtures of ethyl-2-methylbutyrate and ethyl hexanoate with methanol, ethanol, and 1-propanol over the whole composition range have been measured at three different temperatures (293.15, 303.15, and 313.15) K and atmospheric pressure. A Redlich−Kister-type polynomial equation was fitted to the calculated excess molar volumes and viscosity deviations

Density and viscosity of several aldehydes fragrance compounds in their binary mixtures with ethanol at (298.15 K, 308.15 K, and 318.15 K)

Density and viscosity for binary mixtures of hexanal, octanal, nonanal, and decanal with ethanol over the whole composition range have been measured at three different temperatures (298.15, 308.15, and 318.15) K and atmospheric pressure. Redlich−Kister-type polynomial equations were fitted to the calculated excess molar volumes and viscosity deviations