Rayleigh like scattering from silica–titania core-shell particles and their application in protection against harmful ultraviolet rays

Abstract

In this article we report experimental and theoretical results of angle-dependent laser light scattering of nano titanium dioxide nucleated on silica particles. It was observed that the experimental scattering profile from nano-titania coated silica (TCS) particle resembles that of a Rayleigh scattering. It can be inferred from the light scattering profile that nucleating fine particles onto a surface of a bigger particle (core), the resulting scattering profile is dominated by the smaller particles. Thin film transmittance measurement of TCS particles also supports this claim. The theoretical scattering predictions do not match with the experimental findings and the reasons for the discrepancies are addressed. This Rayleigh-like scattering property of TCS particles can be used in cosmetic formulations as a replacement for nanoparticles to provide protection from harmful ultraviolet rays. This study helps to provide insights into these systems for their potential usage in cosmetics.

Development of C-Arylcalix[4]resorcinarenes and C-Arylcalix[4]pyrogallolarenes as Antioxidant and UV-B Protector

“…Sunscreen compounds are classified into two types, i.e., inorganic and organic sunscreens. Some examples of inorganic sunscreens are ZnO, MgO, CaCO3, and TiO2 [7], whereas organic sunscreens generally have conjugated benzene ring with carbonyl groups, such as oxybenzone and octyl methoxycinnamate [8]. Inorganic sunscreens, nowadays, are no longer used because it causes skin allergies and irritation.…”

Mesoporous SiO2–TiO2 nanocomposite for pH sensing

“…In the second step, the decomposition and expulsion of adsorbed organic fraction takes place in the range of A c c e p t e d M a n u s c r i p t 8 water was present in micropores and at the surface walls of composite, which caused a subsequent weight loss of the 7.67 % at this temperature range [33]. This behavior relates to the pyrolysis process of organic dyes, decomposition of surfactant (CTAB) [33], and follows the escape of the physically bound water molecules from the silica-titania intermediate.…”

Performance of Local Clay-Titanium Dioxide Core-Shell Extender Pigments in Alkyd Paints

“…In this theory, a cheap extender being the core is covered by a surface layer of very efficient and expensive pigment-the shell [2]. Core-shell particles are examples of nanostructured materials with functional properties such as composite materials where the morphology, microstructure and chemical composition are controlled to achieve various functional properties [3]. Synthesis of various kinds of core-shell particles were reported several decades ago [4].…”

“…The composite particles having silica core and titania shell are typically synthesized using techniques like layer-by-layer deposition [5]- [8], sol-gel synthesis [9]- [14], laser pyrolysis [15], heterocoagulation [16] and flame synthesis [17]. Most of these methods are difficult to replicate in commercial quantity because of the multiple steps, pH control, ingredients like surfactant polyelectrolytes and cutting-edge technologies required [3]. Many literature sources have revealed excellent report on the preparation of core-shell extender pigments [2] [18].…”