scholarly journals Sodium silicate-derived aerogels: effect of processing parameters on their applications

RSC Advances ◽  
2021 ◽  
Vol 11 (25) ◽  
pp. 15301-15322
Author(s):  
Minju N. ◽  
Balagopal N. Nair ◽  
Savithri S.
Keyword(s):  
Three Dimensional ◽  
Optical Transmittance ◽  
Processing Parameters ◽  
Silica Aerogels ◽  
High Specific Surface Area ◽  
High Porosity ◽  
Open Networks ◽  
Preparation Conditions ◽  
High Optical Transmittance ◽  
Low Refractive Index

Inorganic silica aerogels are large three-dimensional open networks with properties such as low density, high porosity, low thermal conductivity, high specific surface area, low refractive index, and high optical transmittance depending on their preparation conditions.

Electro-Deposition for Foamed Zinc Material from Zinc Sulfate Solution

2007 ◽  
Vol 561-565 ◽  
pp. 1669-1672 ◽  
Author(s):  
Qing Hua Tian ◽  
Xue Yi Guo ◽  
Ping Xue ◽  
Yu Song ◽  
Lian Duan
Keyword(s):  
Ph Value ◽  
Three Dimensional ◽  
Sulfate Solution ◽  
High Specific Surface Area ◽  
High Porosity ◽  
Outward Appearance ◽  
Experimental Conditions ◽  
Electro Deposition ◽  
Zinc Electrodeposition ◽  
Operation Conditions

It is very possible for the foam zinc materials to take the place of zinc powder and become a new ideal material of electrode for zinc-air battery, because of its excellent three dimensional reticulated structure, high porosity, high specific surface area and uniform quality, and was widely used in many other fields. A novel method for preparing very porous zinc foam was proposed, in which the polyurethane foam as substrate was processed by degreasing process, roughening process, activation, electroless plating and zinc electrodeposition. Then, experiments were carried out to explore the effects of the solution composition（concentration of ZnSO4）and the operation conditions （such as the interelectrode distance; current density, temperature, pH value of electroplating solution and so on) on the morphology of the foam zinc and the current efficiency. The optimum experimental conditions were determined by optimizing the factors. On these conditions the foam zinc presents a three-dimensional reticular structure with high porosity, and uniformity, and the outward appearance of the coating is bright.

scholarly journals Nanofibrillated Cellulose-Based Aerogels Functionalized with Tajuva (Maclura tinctoria) Heartwood Extract

Polymers ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 908
Author(s):  
Rodrigo Coldebella ◽  
Marina Gentil ◽  
Camila Berger ◽  
Henrique W. Dalla Costa ◽  
Cristiane Pedrazzi ◽  
...  
Keyword(s):  
Antioxidant Activities ◽  
Three Dimensional ◽  
Nanofibrillated Cellulose ◽  
High Specific Surface Area ◽  
Low Density ◽  
High Porosity ◽  
Porous Networks ◽  
Bonded Particles ◽  
Phenolic Extract ◽  
Cellulosic Pulp

Aerogels are 3-D nanostructures of non-fluid colloidal interconnected porous networks consisting of loosely packed bonded particles that are expanded throughout their volume by gas and exhibit ultra-low density and high specific surface area. Cellulose-based aerogels can be obtained from hydrogels through a drying process, replacing the solvent (water) with air and keeping the pristine three-dimensional arrangement. In this work, hybrid cellulose-based aerogels were produced and their potential for use as dressings was assessed. Nanofibrilated cellulose (NFC) hydrogels were produced by a co-grinding process in a stone micronizer using a kraft cellulosic pulp and a phenolic extract from Maclura tinctoria (Tajuva) heartwood. NFC-based aerogels were produced by freeze followed by lyophilization, in a way that the Tajuva extract acted as a functionalizing agent. The obtained aerogels showed high porosity (ranging from 97% to 99%) and low density (ranging from 0.025 to 0.040 g·cm−3), as well a typical network and sheet-like structure with 100 to 300 μm pores, which yielded compressive strengths ranging from 60 to 340 kPa. The reached antibacterial and antioxidant activities, percentage of inhibitions and water uptakes suggest that the aerogels can be used as fluid absorbers. Additionally, the immobilization of the Tajuva extract indicates the potential for dentistry applications.

scholarly journals NICKEL-GRAPHENE CATALYST FOR MAGNESIUM HYDROGENATION AND FOR CARBON NANOSTRUCTURES SYNTHESIS

2017 ◽  
Vol 60 (8) ◽  
pp. 43
Author(s):  
Boris P. Tarasov ◽  
Artem A. Arbuzov ◽  
Alexei A. Volodin ◽  
Sergey A. Mozhzhukhin ◽  
Mikhail V. Klyuev
Keyword(s):  
Carbon Nanostructures ◽  
Fine Particles ◽  
Three Dimensional ◽  
Catalytic Decomposition ◽  
Reversible Capacity ◽  
High Specific Surface Area ◽  
High Catalytic Activity ◽  
Preparation Conditions ◽  
20 Nm ◽  
Synthesis Duration

The results of obtaining graphene-like nanomaterials (GLM) by reduction of graphite oxide, preparation of nickel-graphene catalysts and formation of carbon-graphene and magnesium-graphene composites are presented. The optimal preparation conditions and the functional characteristics of the obtained materials are determined. The method described in this work makes possible to obtain nickel-graphene composites (Ni/GLM) containing 5–25 wt.% of Ni nanoparticles of size 2–5 nm. Such composites are effective catalysts for the hydrogenation of magnesium. They were used to create hydrogen storage materials on magnesium base with a reversible capacity more 6.5 wt.% of hydrogen. The addition of Ni/GLM promotes an increase in the rate of Mg hydrogenation due to the high catalytic activity of nanoscale Ni in the dissociation of H2 molecules, and the coating of the fine particles of MgH2 with the GLM retains the submicron size of the Mg particles formed during dehydrogenation and ensures high thermal conductivity of the Mg/MgH2 + Ni/GLM composites. It was determined that in MgH2 + Ni/GLM composites, along with the stable α-phase of MgH2, a metastable γ-phase of MgH2 contains, which leads to a decrease in the dehydrogenation temperature by ~ 50 °C. Using Ni/GLM catalysts, carbon nanotubes (CNT) and nanofibers (CNF) on the surface of graphene-like structures were synthesized. The catalytic decomposition of C2H4 on Ni/GLM at temperatures of 500–700 °C leads to the formation of CNF on the surface of the GLM, and the decomposition of CH4 at 900 °C – with the formation of CNT. The CNT and CNF formed have a diameter in the range from 5 to 20 nm, and the length increases from 5 to 300 nm with rise of synthesis duration. Such three-dimensional structures have a high specific surface area and are attractive as sorbents of gases and carriers of metal catalysts.Forcitation:Tarasov B.P., Arbuzov A.A., Volodin A.A., Mozhzhukhin S.A., Klyuev M.V. Nickel-graphene catalyst for magnesium hydrogenation and for carbon nanostructures synthesis. Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol. 2017. V. 60. N 8. P. 43-46.

scholarly journals Preparation and Characterization of Gaphene-Doped Carbon-Aerogel Electrode

2022 ◽  
Vol 2160 (1) ◽  
pp. 012003
Author(s):  
Zhengshun Wang ◽  
Kaizheng Wang ◽  
Jianzhen Mao ◽  
Zaiyong Jiang
Keyword(s):  
Electrode Materials ◽  
Three Dimensional ◽  
Carbon Aerogel ◽  
High Specific Surface Area ◽  
Carbon Aerogels ◽  
Porous Carbon Material ◽  
Low Density ◽  
High Porosity ◽  
Dimensional Network

Abstract Carbon-aerogel is a kind of nano-porous carbon material with special three-dimensional network structure. Electrode materials with high specific surface area, high porosity, superior conductivity and low density were obtained by adding graphene to prepare graphene-doped carbon-aerogels.

Polyetheresterurethane Based Porous Scaffolds with Tailorable Architectures by Supercritical CO2 Foaming

MRS Advances ◽  
2020 ◽  
Vol 5 (45) ◽  
pp. 2317-2330
Author(s):  
Marc Behl ◽  
Muhammad Yasar Razzaq ◽  
Magdalena Mazurek-Budzyńska ◽  
Andreas Lendlein
Keyword(s):  
Pore Size ◽  
Treatment Options ◽  
Three Dimensional ◽  
Processing Parameters ◽  
Attractive Alternative ◽  
Porous Scaffolds ◽  
Potential Candidate ◽  
High Porosity ◽  
Average Pore ◽  
Scaffold Materials

AbstractPorous three-dimensional (3D) scaffolds are promising treatment options in regenerative medicine. Supercritical and dense-phase fluid technologies provide an attractive alternative to solvent-based scaffold fabrication methods. In this work, we report on the fabrication of poly-etheresterurethane (PPDO-PCL) based porous scaffolds with tailorable pore size, porosity, and pore interconnectivity by using supercritical CO2 (scCO2) fluid-foaming. The influence of the processing parameters such as soaking time, soaking temperature and depressurization on porosity, pore size, and interconnectivity of the foams were investigated. The average pore diameter could be varied between 100–800 μm along with a porosity in the range from (19 ± 3 to 61 ± 6)% and interconnectivity of up to 82%. To demonstrate their applicability as scaffold materials, selected foams were sterilized via ethylene oxide sterilization. They showed negligible cytotoxicity in tests according to DIN EN ISO 10993-5 and 10993-12 using L929 cells. The study demonstrated that the pore size, porosity and the interconnectivity of this multi-phase semicrystalline polymer could be tailored by careful control of the processing parameters during the scCO2 foaming process. In this way, PPDO-PCL scaffolds with high porosity and interconnectivity are potential candidate materials for regenerative treatment options.

scholarly journals Mechanical Behavior of Hydroxyapatite-Chitosan Composite: Effect of Processing Parameters

Minerals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 213
Author(s):  
Hamid Ait Said ◽  
Hassan Noukrati ◽  
Hicham Ben Youcef ◽  
Ayoub Bayoussef ◽  
Hassane Oudadesse ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Compressive Strength ◽  
Mechanical Strength ◽  
Bone Repair ◽  
Mechanical Stability ◽  
Three Dimensional ◽  
Processing Parameters ◽  
Composite Effect ◽  
Solid Liquid ◽  
The Impact

Three-dimensional hydroxyapatite-chitosan (HA-CS) composites were formulated via solid-liquid technic and freeze-drying. The prepared composites had an apatitic nature, which was demonstrated by X-ray diffraction and Infrared spectroscopy analyses. The impact of the solid/liquid (S/L) ratio and the content and the molecular weight of the polymer on the composite mechanical strength was investigated. An increase in the S/L ratio from 0.5 to 1 resulted in an increase in the compressive strength for HA-CSL (CS low molecular weight: CSL) from 0.08 ± 0.02 to 1.95 ± 0.39 MPa and from 0.3 ± 0.06 to 2.40 ± 0.51 MPa for the HA-CSM (CS medium molecular weight: CSM). Moreover, the increase in the amount (1 to 5 wt%) and the molecular weight of the polymer increased the mechanical strength of the composite. The highest compressive strength value (up to 2.40 ± 0.51 MPa) was obtained for HA-CSM (5 wt% of CS) formulated at an S/L of 1. The dissolution tests of the HA-CS composites confirmed their cohesion and mechanical stability in an aqueous solution. Both polymer and apatite are assumed to work together, giving the synergism needed to make effective cylindrical composites, and could serve as a promising candidate for bone repair in the orthopedic field.

Preparation and characterization of electrospun cellulose acetate sub-micro fibrous membranes

2021 ◽  
pp. 004051752110117
Author(s):  
Zhenzhen Quan ◽  
Yihan Wang ◽  
Jiajun Wu ◽  
Xiaohong Qin ◽  
Jianyong Yu
Keyword(s):  
Cellulose Acetate ◽  
High Specific Surface Area ◽  
Proper Solution ◽  
High Porosity ◽  
Hydrolysis Time ◽  
Research Fields ◽  
Average Porosity ◽  
Fibrous Membranes ◽  
Microfiber Membrane ◽  
Solution Parameters

Electrospun sub-microfiber membrane of cellulose acetate (CA), with excellent biodegradability, high specific surface area and high porosity, has attracted wide attention in various research fields. Even so, the stable continuous electrospinning of CA sub-micro fibers is affected by the solution parameters and CA acetylation degree dramatically, which still remains challenging. In the present work, electrospun CA sub-micro fibrous membranes have been prepared from four distinct solvent systems, respectively, to explore the proper solution parameters for membrane fabrication. After hydrolysis and electrospinning, the produced CA sub-micro fibrous membranes were analyzed in terms of fiber size distribution, hydrophilicity and porosity. Current analysis has shown that the degree of substitution of CA sub-micro fibers decreases with the increase in hydrolysis time, resulting in increased diameter irregularity, decreased average porosity and increased hydrophilicity of the sub-micro fibrous membrane.

Process Modeling in Laser Deposition of Multilayer SS410 Steel

2007 ◽  
Vol 129 (6) ◽  
pp. 1028-1034 ◽  
Author(s):  
Liang Wang ◽  
Sergio Felicelli
Keyword(s):  
Phase Transformation ◽  
Temperature Distribution ◽  
Three Dimensional ◽  
Element Model ◽  
Traverse Speed ◽  
Processing Parameters ◽  
Dimensional Finite Element ◽  
Net Shaping ◽  
Three Dimensional Finite Element ◽  
Continuous Cooling Transformation Diagram

A three-dimensional finite element model was developed to predict the temperature distribution and phase transformation in deposited stainless steel 410 (SS410) during the Laser Engineered Net Shaping (LENS™) rapid fabrication process. The development of the model was carried out using the SYSWELD software package. The model calculates the evolution of temperature in the part during the fabrication of a SS410 plate. The metallurgical transformations are taken into account using the temperature-dependent material properties and the continuous cooling transformation diagram. The ferritic and martensitic transformation as well as austenitization and tempering of martensite are considered. The influence of processing parameters such as laser power and traverse speed on the phase transformation and the consequent hardness are analyzed. The potential presence of porosity due to lack of fusion is also discussed. The results show that the temperature distribution, the microstructure, and hardness in the final part depend significantly on the processing parameters.

Three-dimensional optofluidic waveguides in hydrophobic silica aerogels via supercritical fluid processing

2013 ◽  
Vol 73 ◽  
pp. 28-33 ◽  
Author(s):  
Gamze Eris ◽  
Deniz Sanli ◽  
Zeynep Ulker ◽  
Selmi Erim Bozbag ◽  
Alexandr Jonás ◽  
...  
Keyword(s):  
Supercritical Fluid ◽  
Three Dimensional ◽  
Silica Aerogels ◽  
Hydrophobic Silica ◽  
Optofluidic Waveguides ◽  
Supercritical Fluid Processing

Considerations for Post-processing Parameters in Mixed-Method 3D Analyses

2021 ◽  
Vol 9 (4) ◽  
pp. 325-337
Author(s):  
Robert Z. Selden ◽  
Lauren N. Butaric ◽  
Kersten Bergstrom ◽  
Dennis Van Gerven
Keyword(s):  
Three Dimensional ◽  
Processing Parameters ◽  
Surface Model ◽  
Digital Repositories ◽  
Computed Tomographic ◽  
Archaeological Data ◽  
3D Data ◽  
Morphometric Analyses ◽  
Smoothing Parameters ◽  
Ct Data

ABSTRACTThe production of three-dimensional (3D) digital meshes of surface and computed tomographic (CT) data has become widespread in morphometric analyses of anthropological and archaeological data. Given that processing methods are not standardized, this leaves questions regarding the comparability of processed and digitally curated 3D datasets. The goal of this study was to identify those processing parameters that result in the most consistent fit between CT-derived meshes and a 3D surface model of the same human mandible. Eight meshes, each using unique thresholding and smoothing parameters, were compared to assess whole-object deviations, deviations along curves, and deviations between specific anatomical features on the surface model when compared with the CT scans using a suite of comparison points. Based on calculated gap distances, the mesh that thresholded at “0” with an applied smoothing technique was found to deviate least from the surface model, although it is not the most biologically accurate. Results have implications for aggregated studies that employ multimodal 3D datasets, and caution is recommended for studies that enlist 3D data from websites and digital repositories, particularly if processing parameters are unknown or derived for studies with different research foci.

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