Monodisperse spherical mesoporous silica particles: fast synthesis procedure and fabrication of photonic-crystal films

Abstract

A procedure for the synthesis of monodisperse spherical mesoporous silica particles (MSMSPs) via the controlled coagulation of silica/surfactant clusters into spherical aggregates with mean diameters of 250-1500 nm has been developed. The synthesis is fast (taking less than 1 h) because identical clusters are simultaneously formed in the reaction mixture. The results of microscopic, x-ray diffraction, adsorption and optical measurements allowed us to conclude that the clusters are ∼15 nm in size and have hexagonally packed cylindrical pore channels. The channel diameters in MSMSPs obtained with cethyltrimethylammonium bromide and decyltrimethylammonium bromide as structure-directing agents were 3.1 ± 0.15 and 2.3 ± 0.12 nm, respectively. The specific surface area and the pore volume of MSMSP were, depending on synthesis conditions, 480-1095 m(2) g(-1) and 0.50-0.65 cm(3) g(-1). The MSMSP were used to grow opal-like photonic-crystal films possessing a hierarchical macro-mesoporous structure, with pores within and between the particles. A selective filling of mesopore channels with glycerol, based on the difference between the capillary pressures in macro- and mesopores, was demonstrated. It is shown that this approach makes it possible to control the photonic bandgap position in mesoporous opal films by varying the degree of mesopore filling with glycerol.

Colloidal Mesoporous Silica Nanoparticles

“…70 Furthermore, Trofimova et al also prepared monodispersed MSNs with large size through one-pot process with short reaction time. 50 On the other hand, the seedgrowth method is also known to be an effective method to obtain monodispersed MSNs. Mou et al prepared MSNs with very narrow size distribution through separate additions of the silica source, and fabricated 2D colloidal crystals.…”

Монодисперсные Частицы Со Структурой Ядро--Оболочка Из Магнетита И Функционализированного Люминофором Мезопористого Кремнезема

“…МСМЧК синтезированы гидролизом тетраэтоксисилана в спирто-водно-аммиачной среде, содержащей поверхностно-активный структу-рообразующий агент [11]. Методика синтеза обеспечивает получение монодисперсных сферических частиц с контролируемо варьируемым средним диаметром в диапазоне от 50 до 1500 nm.…”

Analysis of Styrene Polymerization Without Surfactant and N2 Gas in Cylindrical Flask.

“…Synthesis of spherical particles with well defined size has also been the object of research, due to its application in the field of [17][18][19][20] . Beads can be synthesized in different sizes at nanometric scale and support high temperature and pressure conditions making them ideal for preparation of semiconductor materials.…”