Dependence of the fractality of the silica gel on the method of sol emulsification

The article presents experimental data confirming the effect of capillary active substance (surfactants) and sedimentation stability on the final structure of the gel with stabilized silicic acid. Studies of the macrostructure of silica gel depending on the method of emulsifi ation of silicic acid sol and the effect of the resulting fractality on the strength of the mold are presented.The direction of modifying the binder for lost‑wax casting (LWC) with obtaining the specified properties of the ceramic shell is shown.The complex effect of organic polymers on the sol – gel system has been established. The conclusion is made about the possibility of using an aqueous dispersion of acrylic to form a given structure of a silica gel.

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Resistance to Growth of Molds for Wood Modified with Hydrophobic Hybrid Silica Gel Containing Copper Amine Complexes

Materials ◽

10.3390/ma14030577 ◽

2021 ◽

Vol 14 (3) ◽

pp. 577

Author(s):

Shaokun Hao ◽

Chuanshuang Hu ◽

Xiuyi Lin ◽

Jin Gu ◽

Hong Yun ◽

...

Keyword(s):

Silica Gel ◽

High Efficiency ◽

Copper Chloride ◽

Sol Gel ◽

Untreated Wood ◽

Populus Tomentosa ◽

Amine Complexes ◽

Hybrid Silica ◽

Sol Gel Process ◽

Copper Amine

Complexation copper with amine provides an effective strategy for fixation copper in wood, while hydrophobic modification improves the dimensional stability of wood. Thus, a combination of complexation and hydrophobization is expected to enhance the efficiency of copper-based biocides. In this study, hydrophobic hybrid silica gel containing copper amine complexes (MACu) was prepared through an in situ sol-gel process in wood using methyltriethoxysilane (MTES), 3-amino-propyltriethoxysilane (APTES), and copper chloride. The resistance to growth of molds for MACu modified wood (Populus tomentosa) was measured according to ASTM D3273-16. A leaching resistance test was carried out in accordance with AWPA E11-16. The results showed that only Aspergillus niger covered the surface of untreated wood blocks and no mold grew on the MACu surface even after the leaching test. MACu xerogel and MACu wood were further characterized by SEM-EDS, FTIR, and XPS. A possible schematic diagram of the reaction mechanism was proposed to explain the high-efficiency anti-mold performance of MACu wood.

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ChemInform Abstract: Sol-Gel Synthesis of Carbon/Silica Gel Electrodes for Lithium Intercalation.

ChemInform ◽

10.1002/chin.200008011 ◽

2010 ◽

Vol 31 (8) ◽

pp. no-no

Author(s):

Gerko Oskam ◽

Peter C. Searson ◽

T. Richard Jow

Keyword(s):

Silica Gel ◽

Sol Gel ◽

Lithium Intercalation ◽

Sol Gel Synthesis

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A NEW ORGANIC/INORGANIC HYBRID WITH HIGH ELECTRORHEOLOGICAL ACTIVITY

International Journal of Modern Physics B ◽

10.1142/s0217979202012505 ◽

2002 ◽

Vol 16 (17n18) ◽

pp. 2454-2460 ◽

Cited By ~ 4

Author(s):

X. P. ZHAO ◽

X. DUAN

Keyword(s):

Activation Energy ◽

Shear Stress ◽

Necessary Conditions ◽

Sol Gel ◽

Root Temperature ◽

Sedimentation Stability ◽

Inorganic Hybrid ◽

Active Particles ◽

Static Shear

In-situ sol-gel method to prepare colloidal hybrids of surfactant modified polysucchride and titanium oxide has been presented, and experiments indicated these highly ER active particles exhibited a remarkable ER effect. The static shear stress can be up to 37 k Pa (shear rate 5 S -1) under DC field of 4 kV/mm at root temperature, well above that of simple blends of starch and TiO 2. In the meanwhile, temperature dependence and sedimentation stability were also greatly improved. Based on recent experimental facts, we find that dielectric properties and surface (interface) activity are two necessary conditions fulfilling the requirement of high ER activity. Adequate grinding of particles with oil can effectively enhance the shear stress, which may be owed to the decline of the activation energy needed for restructuring. It has provided us a new horizon for preparation of excellent ER materials and further studies should be continued to make.

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Control of Hierarchically Ordered Positive and Negative Replicas of Wood Cellular Structures by Surfactant-Directed Sol-Gel Mineralization

MRS Proceedings ◽

10.1557/proc-726-q5.4 ◽

2002 ◽

Vol 726 ◽

Author(s):

Yongsoon Shin ◽

Jun Liu ◽

Li-Qiong Wang ◽

Jeong Ho Chang ◽

William D. Samuels ◽

...

Keyword(s):

Silicic Acid ◽

Cell Walls ◽

Cellular Structure ◽

Sol Gel ◽

Ceramic Materials ◽

Silica Particles ◽

Low Ph ◽

Cellular Structures ◽

Inner Surface

AbstractWe here report the synthesis of ordered ceramic materials with hierarchy produced by an in-situ mineralization of ordered wood cellular structures with surfactant-templated sol-gel at different pH. At low pH, a silicic acid is coated onto inner surface of wood cellular structure and it penetrates into pores left, where degraded lignin and hemicellulose are leached out, to form a positive replica, while at high pH the precipitating silica particles due to fast condensation clog the cells and pit structures to form a negative replica of wood. The calcined monoliths produced in different pHs contain ordered wood cellular structures, multi-layered cell walls, pits, vessels well-preserved with positive or negative contrasts, respectively. The surfactant-templated mineralization produces ordered hexagonal nanopores with 20Å in the cell walls after calcination.

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