Revision of the opinion on Silica, Hydrated Silica, and Silica Surface Modified with Alkyl Silylates (nano form)

This work reports on the nanoscale assembly of hybrid lanthanum oxide and silica structures, which form patterns of interfacial dense and porous networks. It was found that increasing the molar ratio of lanthanum nitrate to tetraethyl orthosilicate (TEOS) in an acid catalysed sol-gel process alters the expected microporous metal oxide silica structure to a predominantly mesoporous structure abo...

nano-silica supported titanium tetrachloride (ticl4.sio2) was prepared and used as an acid catalyst for the 14-aryl or alkyl-14h-dibenzo[a,,j]xanthenesreaction under solvent-free conditions. compared to the classical 14-aryl or alkyl-14h-dibenzo[a,j]xanthenesreaction conditions, this method consistently has the advantage of excellent yields, mild reaction conditions, ease of workup, survival of...

Introduction: One of the clinical problems in orthodontics is the bonding of brackets tocomposite restorations. The aim of this study was to evaluate the shear bondstrength of brackets bonded to composite restorations using Excite. Methods:Forty brackets were bonded to composite surfaces, which were embedded inacrylic resin. One of the following four protocols was employed for surfacepreparatio...

introduction: the purpose of the present study was to determine the effect of 17% ethylene,di-amine, tetra-acetic acid (edta), 6% phosphoric acid and erbium: yttrium, aluminum, garnet (er:yag) laser in removing the smear layer by scanning electron microscopy. methods: in this study, 80 single-rooted human teeth were selected. instrumentation was done by use of hand files and step-back technique...

one-pot multicomponent reaction between isatin, barbituric acid, and 6-amino-1,3-dimethyl uracil was investigated in the presence of sulfonic acid functionalized nanoporous silica (sba-pr-so3h) and resulted in the formation of spirooxindole dipyrimidines. spirooxindole unit is found in many natural products and biologically active molecules and 1,4-dihydropyridines are an important class of com...

a convenient, rapid, and one-pot method for the synthesis of azo dyes has been developed. in this protocol, diazotization reagent (arn2+ -cro3–sio2) was prepared via grinding of aromatic amines, nano2, wet sio2 and nano silica chromic acid (nano-sca) without solvent at room temperature. the obtained diazotization reagent was sufficiently stable to be kept at room temperature in the dry state fo...

OBJECTIVES The purpose of this study was to evaluate the effect of the pre-conditioning step using different dentin conditioners on the shear bond strength (SBS) of the nano-filled resin-modified glass ionomer (RMGI) to dentin. METHODS Twenty-four human molars were used in this study. Subsequent to teeth sectioning in the mesio-distal direction and creation of the smear layer, the teeth were ...

self etching primers, due to ease of manipulation, have been extensively used in recent years. these self etching primers containing a relatively weak acid, may not provide an optimal bond strength. the purpose of the present in-vitro investigation was to evaluate the effects of 37% phosphoric acid application prior to applying self etching primers on composite bond strength. in this experiment...

This article reviews the analytical methods for crystalline silica polymorphs and summarizes promising techniques for compliance with health-related regulations. X-ray diffraction analysis appears to be the most promising method of determining quartz and cristobalite content at this threshold in many bulk mineral and chemical systems. Other analytical techniques can be used in some mineral and ...