The aggregation behavior of a novel histidine derivative surfactant N-dodecanoyl-L-histidine (DHis) in aqueous solution was investigated. By mixing with cationic/anionic surfactant, an interesting phase transition over time from transparent homogeneous solution to jelly and finally to fibrous floccules was observed with aggregates growth taken place in the systems. Making use of the growing fib...

Sol-gel derived silica possess many promising features, including low-temperature preparation procedure, porosity, chemical and physical stability. Applications exploiting porous materials to encapsulate sensor molecules, enzymes and many other compounds, are developing rapidly. In this paper some potential applications, with emphasis on biomedical and environmental ones, are reviewed. The mate...

a type of zeolite from the analcime family was prepared by using triethanolamine, silica gel and sodium aluminate. the average particle size was around 24 µm. ftir, xrd and sem results approved the type of zeolite which was formed

the solvent free route for the synthesis of diaryl sulfoxides from arenes and thionyl chloride in the presence of lewis acids such as aluminum chloride and ferric chloride on silica gel are described.

Spherical silica nanoparticles (n‐SiO2) with controllable size have been synthesized using tetraethoxysilane as starting material and ethanol as solvent by sol‐gel method. Morphology and size of the particles was controlled through surfactants. Sorbitan monolaurate, sorbitain monopalmitate and sorbitain monostearate produced silica nanoparticles of varying siz...

Reported silica aerogels have a thermal conductivity as low as 15 mW/mK. The fragility of silica aerogels, however, makes them impractical for structural applications. The purpose of the study is to improve the ductility of aerogels while retain the low thermal conductivity of silica aerogels. We have established a new synthesis route, a 3-step sol-gel processing method. The method provides bet...

The effects of resin molecular weight on the flame-retardant mechanism of silica were studied with two different molecular weights of poly(methyl methacrylate) (PMMA), 122,000 and 996,000 g/mol, and two silicas, fused silica with a small surface area and silica gel with a large surface area. A total of six different samples were studied, with a mass fraction of 10% silica. The mass loss rate of...

............................................................................................................... XVII CHAPTER 1: INTRODUCTION ................................................................................... 1 1.1 NANOTECHNOLOGY ................................................................................................ 1 1.2 SUPERPARAMAGNETIC IRON OXIDE NANOPARTICLES ........

background and objectives: the plants belonging to the genus heliotropium l. (boraginaceae) are the main sources of toxic pyrrolizidine alkaloids (pas). in the present study, we have investigated the pas of the aerial parts of heliotropium transoxanum bunge, a perennial species native to iran. methods: silica gel column chromatography and silica gel ptlc were applied for the isolation of pas pr...

Sulphuric acid adsorbed on silica gel is a practical and useful catalyst for acetylation of varius alcohols, Phenols and amines.