Effects of Hydrochloric Acid Catalyst Concentration on Crystallization of Sol-Gel Derived CaMgSi2O6 Gels.

Currently, xerogel has been applied as a filtration material, especially in membrane desalination. However, the xerogel matrix structure for desalination have to be designed properly in order to allow rejection of salt and obtain good hydro-stability, thus, silica precursor in the form of TEOS (tetraethyl orthosilicate)/TEVS (triethoxy vinyl silane) and organic acid catalyst are suitable material for fabrication. The aim of this study is therefore to fabricate and perform deconvolution of TEOS/TEVS xerogel by adding single or dual catalyst, using FTIR (Fourier-transform Infrared Spectroscopy) and Fityk software. The xerogel was fabricated by dried silica sol and calcined using RTP technique (rapid thermal processing) at 450 °C. Prior to this fabrication, the silica sol was synthesized by sol gel method, using a mixture of silica precursor TEOS/TEVS, ethanol solvent, and varied addition of single catalyst (citric acid) as well as dual catalyst (citric acid + ammonia) for 2 hours, at 50 °C. Subsequently, the xerogel was characterized by FTIR and the deconvolution was obtained through Gaussian approach, with Fityk software. All TEOS/TEVS xerogel samples indicated existence of silanol (Si-OH), siloxane (Si-O-Si) and silica-carbon (Si-C) functional groups. The xerogel deconvolution of TEOS/TEVS using single catalyst exhibit a peak area ratio of Si-OH/Si-O-Si, and this is similar to the dual catalyst counterpart of 0.24 (unit area) and 1.86 (unit area), for Si-C area ratio. This shows the addition of single catalyst was enough to produce deconvolution in TEOS/TEVS xerogel, dominated by siloxane functional group and carbon bonds with the ability to enhance membrane material hydro-stability’s fabrication.

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Evaluation and Data Analysis of Sol-Gel Method with Acids to Determine Most Effective Sol-Gel Method

10.33774/chemrxiv-2021-j3jnl ◽

2021 ◽

Author(s):

Joshua Moore ◽

Aniska Ramsay

Keyword(s):

Data Analysis ◽

Sol Gel ◽

Acid Catalyst ◽

Nanocomposite Materials ◽

Gel Method ◽

Sol Gel Method ◽

Sio2 Nanocomposites ◽

Time Manipulation

Synthesizing nanocomposite materials using sol-gel methodology is a cheap and effective method for creating quality U3O8 particles. To some degree acids can influence the synthesis of the nanoparticles by catalyzing the reaction. This paper presents important details comparing different acids used as catalysts in nanocomposite synthesis versus time manipulation to determine if an acid catalyst is necessary for the synthesis of U3O8/SiO2 nanocomposites.

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Computational calculation of acetalization of 2-chlorobenzaldehyde reaction mechanism using hydrochloric acid catalyst with ab initio method

Jurnal Pendidikan Kimia ◽

10.24114/jpkim.v12i1.17707 ◽

2020 ◽

Vol 12 (1) ◽

pp. 1-9

Author(s):

Muhammad Yusuf ◽

Keyword(s):

Reaction Mechanism ◽

Hydrochloric Acid ◽

Ab Initio ◽

Acid Catalyst ◽

Ab Initio Method ◽

Computational Calculation

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Structure and Properties of Resorcinol-Formaldehyde Gels

MRS Proceedings ◽

10.1557/proc-177-275 ◽

1989 ◽

Vol 177 ◽

Cited By ~ 5

Author(s):

Stephan A. Letts ◽

Steven R. Buckley ◽

Fung-Ming Kong ◽

Edward F. Lindsay ◽

Margaret L Sattler

Keyword(s):

Catalyst Concentration ◽

Sol Gel ◽

Freeze Fracture ◽

Effect Of Temperature ◽

Condensation Polymerization ◽

Resorcinol Formaldehyde ◽

Solids Concentration ◽

Rate Of Increase ◽

Sol Gel Transition ◽

20 Nm

ABSTRACTThe condensation polymerization of resorcinol and formaldehyde catalized by sodium carbonate produces a sol that aggregates to form a gel. Using viscometry the effect of temperature and catalyst concentration on the sol-gel transition was investigated. At a solids concentration of 3%, gelation occurred in 1500 minutes. The rate of increase in viscosity was a function of both catalyst concentration and temperature. The structure of the gels was studied by freeze-fracture TEM. In the sol phase the RF solutions contain particles of 5 to 20 nm diameter. After gelation the particles form a crosslinked network with a pore structure of 100 nm.

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Synthesis of 2,3-dihydroquinazolin-4(1H)-ones catalyzed by Perchlorated Zirconia (HClO4/ZrO2) nanoparticles as a novel solid acid catalyst

Nanoscience and Nanotechnology ◽

10.18063/nn.v0i0.449 ◽

2018 ◽

Vol 2 (2) ◽

Author(s):

Seyed Yousef Mosavian

Keyword(s):

Solid Acid ◽

Condensation Reaction ◽

Solid Acid Catalyst ◽

Sol Gel ◽

Acid Catalyst ◽

Catalytic Performance ◽

Acid Sites ◽

Zro2 Nanoparticles ◽

Calcination Temperatures ◽

Aldehydes And Ketones

Zirconia was synthesized in nanosize by sol-gel method and perchlorated zirconia (HClO4/ZrO2) with various calcination temperatures were prepared and characterized by XRD, FTIR and SEM techniques. The catalyst acidity characters, including the acidicstrength and the total number of acid sites were determined by potentiometric titration. The catalytic performance experiments show that the HClO4/ZrO2 with calcination temperature of 300 °C has the best catalytic activity. 2,3-Dihydroquinazolin-4(1H)-ones wereprepared in good to excellent yields via condensation reaction of oaminobenzamide and various types of aldehydes and ketones in the presence of HClO4/ZrO2 nanoparticles as an efficient solid acid catalyst. The catalyst is reusable with moderate loss in activity.

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Synthesis of Ca-Doped Three-Dimensionally Ordered Macroporous Catalysts for Transesterification

Advances in Materials Science and Engineering ◽

10.1155/2018/8056701 ◽

2018 ◽

Vol 2018 ◽

pp. 1-7 ◽

Cited By ~ 1

Author(s):

Tanat Chokpanyarat ◽

Vittaya Punsuvon ◽

Supakit Achiwawanich

Keyword(s):

Reaction Time ◽

Catalyst Concentration ◽

Sol Gel ◽

Biodiesel Production ◽

Molar Ratio ◽

The Novel ◽

X Ray Diffraction ◽

X Ray ◽

Hierarchical Porous ◽

Ordered Macroporous

The novel three-dimensionally ordered macroporous (3DOM) CaO/SiO2, 3DOM CaO/Al2O3, and 3DOM Ca12Al14O32Cl2 catalysts for biodiesel transesterification were prepared by sol-gel method. The 3DOM catalysts were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR). The hierarchical porous structure was achieved; however, only 3DOM CaO/Al2O3 and 3DOM Ca12Al14O32Cl2 catalysts were used for transesterification due to high amount of active CaO. Various parameters such as methanol to oil molar ratio, catalyst concentration, reaction time, and their influence on the biodiesel production were studied. The result showed that 99.0% RPO conversion was achieved using the 3DOM Ca12Al14O33Cl2 as a catalyst under the optimal condition of 12 : 1 methanol to oil molar ratio and 6 wt.% catalyst with reaction time of 3 hours at 65°C.

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