The Analysis of Hierarchical Structure of Mesoporous Silica in Nanometer Scale by Small Angle Scattering Method

Abstract

The analysis of hierarchical structure of mesoporous silica material with template of cetyltrimethylammonium bromide (CTAB) with co-surfactants of tetramethylammonium hydroxide (TMAOH) and Triton X-100 was conducted by using the technique of small angle scattering (SAS) using neutron (SANS) and X-ray (SAXS). The analysis was supported by the data of nitrogen absorption and electron microscopy. The analysis showed that the concentration of CTAB affected the characteristics and pore structures of particles. The increase of co-surfactant concentrations tended to form particles that were more uniform in size and more regular in the shape of the sphere. The results of SAS analysis showed that the morphology, shape, and size of the large particles were arranged by smaller (primary or secondary) particles that had pores. The variation of surfactant templates had influenced the formation of pore structure. For CTAB-TMAOH, it had resembled MCM-41 type which has a hexagonal structure, whereas for CTAB-Triton X-100, it would have resembled MCM-48 type which has a cubic structure. The particles that have a high surface area which resembled pore structure MCM-41 has been able to set up by using 0.25 M of CTAB with 0.040 M of TMAOH. Moreover, the particles which resembled pore structure MCM-48 were able to set up by using 0.03 M of Triton X-100 with 0.4 M of CTAB. The analysis of SANS data that was supported by electron microscopy results is entirely showing a complete information of the particles formed by each template. Whereas SAXS analysis that supported by nitrogen adsorption method is fully confirming the information of pore characteristics.

Ordered Structure Analysis of Prepared Mesoporous Silica Using Small Angle X-Ray Scattering

“…For example, the presence of Na + cations reduces the critical micelle temperature (CMT) but increases the cloud point (CP) and solubility of Pluronic P123. In addition, sodium ions increase the solvophobicity of PEO and PPO chains [11]. Using quantum chemistry approach, there are two main effects of the presence of Na + on solvophobic forces, i.e., firstly, the direct effect on electrostatic terms (the free energy of interaction ∆G int and the free energy of reduction ∆G int ) and secondly, a change in the cavity surface squeeze effect [18].…”

“…There are several characterization techniques commonly used such as electron microscopy, X-ray diffraction and small-angle scattering (SAS). For information on the structure of materials, X-ray diffraction is generally used, whereas surface morphology is commonly examined by electron microscopy, and information on the structures hierarchy of mesoporous materials is more appropriately determined by small-angle scattering technique [11]. Different characterization techniques have different length scales capabilities, and therefore a combination of techniques is often needed in order to obtain a complete picture of the nucleation and growth of the mesoporous materials.…”

Sintesis Dan Karakterisasi Urea-Hidroksiapatit Dengan Variasi Ca(OH)2 Sebagai Kandidat Pupuk Lepas Lambat

“…Teknik bottom-up merupakan teknik sintesis dengan hasil homogenitas partikel yang cukup tinggi (Hadi et al, 2018). Untuk mengetahui hasil sintesis urea-hidroksiapatit perlu dilakukan karakterisasi Scanning Electron Microscopy (SEM) untuk mengamati morfologi partikel, Energy Dispersive X-Ray Spectrometry (EDX) untuk mengamati komposisi unsur, Fourier Transform Infrared Spectrometer (FTIR) untuk mengamati ikatan antara unsur dan Particle Size Analyzer (PSA) untuk mengamati distribusi ukuran partikel.…”