One pot preparation of silver nanoparticles decorated TiO2 mesoporous microspheres with enhanced antibacterial activity.

We report a simple "one-pot" solvothermal preparation of silver nanoparticles (Ag NPs) decorated mesoporous titania (TiO2) microspheres as an effective antibacterial agent. TBOT as Ti source was hydrolyzed and crystallized in media composed of acetic acid and ethanol, in which esterification catalyzed by TBOT occurred for in-situ "controlled water release". AgNO3 as Ag source was reduced by ethanol to form Ag NPs embedded in the TiO2 microspheres.

Synthesis and characterization of quaternized beta-chitin.

Water-soluble 2'-O-hydroxypropyltrimethylammoniumchitin chloride (2'-O-HTACCt) was prepared directly from beta-chitin and 3-chloro-2-hydroxypropyltrimethylammonium chloride (CTA) in basic medium. The effect of alkali concentration, reaction temperature, reaction time, and dosage of CTA on yield and degree of substitution (DS) of 2'-O-HTACCt were studied. These quaternized chitin derivatives were characterized by FTIR and (1)H NMR spectroscopy, conductometric titration, and elemental analysis methods.

[Harmful elements removal from Polygonum multiflorum by supercritical CO2 extraction].

Objective: To remove harmful elements as copper, lead and arsenic from Polygonum multiflorum, a Chinese traditional medicine, by supercritical carbon dioxide extraction.

Methods: With sodium diethyldithiocarbamate (NaDDC) as a chelating agent and ethanol as a modifier, the effects of extraction style, time, pressure, temperature and amount of chelating agent on chelating extraction process were discussed.

Results: The condition was optimized as following: 28 MP as extraction pressure, 60 degrees C as extraction temperature, 1 h as static extraction time, 2 h as dynamic extraction time, m(herb) : m(NaDDC) = 5 : 1, m(herb) : m(ethanol) = 1 : 1.