Functional role of cationic surfactant to control the nano size of silica powder

Abstract

Preparation of dispersed, amorphous, spherical silica nanoparticles using cationic surfactant as organic template, tetraethoxysilane (TEOS) as silica precursor and ammonia as catalyst has been carried out using sol gel process. The aim of the present study was to evaluate the simultaneous effects of cationic surfactant on the textural and structural properties of silica nanoparticles. We used a series of the cationic surfactants, dodecytrimethylammonium bromide (DTAB), tetradecyltrimethylammonium bromide (TTAB) and cetyltrimethylammonium bromide (CTAB) to evaluate the effects of the chain length of cationic surfactant on the grain size of silica nanoparticles. The size of silica nanoparticles can be finely tuned in the range *50-100 nm by changing the chain length of cationic surfactant. Decreasing the particle size of silica nano particles resulted in increase in chain length of cationic surfactant. Further, these silica nanoparticles are incorporated with cement paste to evaluate the beneficial effect on mechanical properties of cement. Synthesized silica nanoparticles were analyzed using scanning electron microscopy (SEM), 29 Si MAS NMR, powder X-ray diffraction techniques (XRD) and IR studies.

The effects of seawater on the hydration, microstructure and strength development of Portland cement pastes incorporating colloidal silica

“…It has been reported that nanosilica (NS) have a significant impact on accelerating the hydration process of cement (Singh et al 2011;Land and Stephan 2012;Skoczylas and Rucińska 2018a), refining the pore structure of cement matrices (Sikora et al 2016), improving early and long-term mechanical properties (Skoczylas and Rucińska 2018b), as well as improving the durability performance Submitted to special issue NANO-2018 within the 6th International Conference "Nanotechnologies and Nanomaterials" NANO-2018. of cementitious composites (Du et al 2014;Heikal et al 2016;Marushchak et al 2017). The beneficial effect of silica nanoparticles is attributable to three synergistic effects: (i) the filler effect-nanosized silica particles fill the voids in the cement matrix, decreasing paste porosity and optimizing the distribution of the pore structure; (ii) the nucleation effect-ultrafine silica nanoparticles act as the nucleation sites (kernels) for the hydration reaction of the cement; (iii) the pozzolanic effect-through the reaction of silica nanoparticles with calcium hydroxide (CH), the amount of calcium silicate hydrate (C-S-H) gel increases (Singh et al 2011(Singh et al , 2013Abd El-Aleem and Ragab 2014;El-Didamony et al 2016;Маrushchak et al 2016;Xu et al 2016;Rupasinghe et al 2017). The effects of NS on the properties of cement-based composites have been investigated in detail in recent years and many review papers are available (Singh et al 2013;Safiuddin et al 2014;Aggarwal et al 2015;Silvestre et al 2015;Shah et al 2015;Bastos et al 2016;Sikora et al 2018).…”

Pore ordering in mesoporous matrices induced by different directing agents

“…The increase of template agent chain length from 12 to 16 methyl groups results in increasing of the pore mean diameter [12,16]. The two dimension parameters may also correlate: in an ammonia catalyzed synthesis, the particle size decreased as the chain length of the surfactant increased [17].…”

Photophysical studies of newly derivatized mono substituted phthalocyanines grafted onto silica nanoparticles via click chemistry

“…Fig. 6(i), representing the azide functionalized SiNPs, shows a broad peak centred at 2h = 22.4°(d-spacing at 3.96), while the confirms the amorphous nature of the SiNPs, which is maintained after functionalization [31,32].…”