Mechanically Strong and Hierarchical Porous Silica Ceramics via Gelcasting-Lyophilization

2016 ◽  
Vol 697 ◽  
pp. 414-418
Author(s):  
Wei Wan ◽  
Jian Yang ◽  
Yong Bao Feng ◽  
Tai Qiu

Highly porous silica ceramics were prepared by in-situ gelation of an aqueous suspension with well dispersed silica particles and N’N-dimethylacrylamide (DMAA) monomer, followed by lyophilization and pressureless sintering. The gelcasting process was imparted by polymerization of DMAA. The silica raw materials used in this experiment are the dusts collected from the exhaust fumes of silicon industry. The as-obtained porous silica ceramics had three-dimensional and hierarchical pore structure and the porosity ranged from 75 to 88 % as the sintering temperature varied from 850 to 1050 °C. In addition, the porous silica ceramics appeared to have strong mechanical strength. Compressive strength of the porous silica ceramics was as high as 3.2 MPa even when the porosity was nearly 80%. The gelcasting-lyophilization method was proved to be a novel and promising route for the preparation of highly porous and mechanically strong materials.

2018 ◽  
Vol 222 ◽  
pp. 01013 ◽  
Author(s):  
Katarzyna Pacewicz ◽  
Anna Sobotka ◽  
Łukasz Gołek

Three dimensional printing is a promising new technology to erect construction objects. Around the world in every moment a new prototypes constructions are made by using this method. Three dimensional printing is taken into account as technology which can be used to print constructions in automated way on the Moon or Mars. The raw materials, which can be used with three dimensional printing have to fulfil basic requirements for those which are used in construction. That means that components of printing mortars are made from ingredients easily accessible in area nearby construction site and can be reusable. The cost of printing building objects due to that requirements is comparable to costs of traditional building, which are currently available. However additive techniques of printing needs a dedicated mortars for printer supplying. Characteristic for such mortars is: setting time, compressive strength, followability in the printing system, shape stability of every printed layer, controlling the hydration rate to ensure bonding with the subsequent layer, reusable capabilities, easily accessible raw materials, cost of such mixtures shouldn’t be too high in order to keep 3D printing competitive for traditional ways of building, mortar components should be recyclable and printing process should not influence negatively on an environment and people. All properties of printing mortars are determined by the device for additive application method. In this paper review of available materials used for three dimensional printing technology at construction site is presented. Presented materials were analysed in terms of requirements for building materials technology. Due to the lack of detailed information’s in available literature, regarding to the properties of raw materials, the results of this analysis may be used in the designing of new concrete mixtures for the use in three-dimensional printing technology for construction.


2018 ◽  
Vol 928 ◽  
pp. 168-174 ◽  
Author(s):  
Ming Yu Yang ◽  
Zheng Hong Zhu

The purpose of this paper is to explore the potential of tablet manufacturing technology combined with 3D printing technology. The acetaminophen raw materials used for 3D printing are formulated in a clean environment according to the actual amount. And homemade material mixed-type three-dimensional printer is used to print double-layer acetaminophen tablets. In this paper, the factors influencing the quality of the tablet were explored by orthogonal experiments, and the optimal parameters were obtained. In order to determine whether the tablet meets the quality requirements, the hardness, friability and dissolution profiles of the 3D printing tablets were determined by the test instrument.


2018 ◽  
Vol 768 ◽  
pp. 224-230
Author(s):  
Dao Yan Feng ◽  
Yu Xiao Li ◽  
Hui Yang ◽  
Xing Zhong Guo

Hierarchical porous SiO2@C@MnO2monoliths have been fabricated by two step approaches: Elemental carbon was covered the internal surface of porous silica monoliths with impregnation and carbonized in inert atmosphere, and MnO2was directly grown on the skeleton of SiO2@C accompanied by redox reaction between C and KMnO4. The effects of glucose and KMnO4concentrations, and hydrothermal reaction on the morphology of MnO2particles on the surface of SiO2monoliths were investigated in detail. The results showed that the optimal factors of reaction condition involved 0.08 mol·L-1glucose solution, 0.03 mol·L-1KMnO4solution and the reaction time of 5 h. SEM images and BET results indicated that the macroporous structure of the as-prepared material was preserved after modification, while the specific surface area and pore volume decreased with increasing amount of MnO2to some degree. The XPS spectra of SiO2@C@MnO2is in good agreement with reported data in MnO2. The crystal phase of MnO2was α-MnO2after thermal treatment at the temperature of 600 °C from the XRD patterns. Three-dimensional porous well-defined morphological SiO2@C@MnO2be promising materials for the catalytic elimination of air pollutants since large quantities can be obtained from porous structure combined with α-MnO2equipped with high active performance.


2010 ◽  
Vol 434-435 ◽  
pp. 674-677 ◽  
Author(s):  
Li Zhong Zhou ◽  
Chang An Wang ◽  
Yong Huang

Porous silica ceramics with above 70% porosity were fabricated by gelcasting process using tert-butyl alcohol (TBA) as solvent. Two types of starting powders, α-silica and fused silica, were chosen to fabricate porous silica ceramics. According to XRD analysis, only single α-cristobalite phase can be identified in the sintered samples. SEM observation showed that highly porous skeleton formed by the bonding of molten ceramic particles in porous silica ceramics. Comparing to the samples using α-silica as starting materials, a compressive strength of 6.30MPa was achieved at a porosity of 70.7% when using fused silica as starting materials. A relatively high specific surface area higher than 10m2/g was obtained for both samples, which should be suitable for catalysis applications as catalyst supports.


Author(s):  
Celalettin Değerli ◽  
Sedef Nehir El

Three dimensional (3D) printing technology, have been quite popular in recent years. It came out first in the area of material production, but now, it has been applied on the other possible fields like food production. In this review, historical period of 3D printing, 3D printer types and working principles, studies on 3D food printing until today and the raw materials used in this studies were investigated. Studies on food printing was also categorised according to food types. Also, the impacts of 3D printing technology on food sector from the point of producer and consumer and future needs were discussed.


2016 ◽  
Vol 19 (2) ◽  
pp. 93-100
Author(s):  
Lalita El Milla

Scaffolds is three dimensional structure that serves as a framework for bone growth. Natural materials are often used in synthesis of bone tissue engineering scaffolds with respect to compliance with the content of the human body. Among the materials used to make scafffold was hydroxyapatite, alginate and chitosan. Hydroxyapatite powder obtained by mixing phosphoric acid and calcium hydroxide, alginate powders extracted from brown algae and chitosan powder acetylated from crab. The purpose of this study was to examine the functional groups of hydroxyapatite, alginate and chitosan. The method used in this study was laboratory experimental using Fourier Transform Infrared (FTIR) spectroscopy for hydroxyapatite, alginate and chitosan powders. The results indicated the presence of functional groups PO43-, O-H and CO32- in hydroxyapatite. In alginate there were O-H, C=O, COOH and C-O-C functional groups, whereas in chitosan there were O-H, N-H, C=O, C-N, and C-O-C. It was concluded that the third material containing functional groups as found in humans that correspond to the scaffolds material in bone tissue engineering.


2014 ◽  
Vol 6 (2) ◽  
pp. 1
Author(s):  
Saibatul Hamdi

The purpose of this research is to know the mechanical strength of gypsum board by utilizing waste sawn wood. Raw materials used consist of flour, gypsum,wood particles, boraks and kambang (Goniothalamus sp), wood tarap (Artocarpus elasticus REINW) and lua (Ficus glomerata ROXB). Wood particle 40 mesh and 60 mesh, concentrations boraks of 1 and 2 and the percentage particles of gypsum sawn timber is 300, 400 and 500%. The results showed that the average value Modulus of Rufture (MoR) in lua wood ranges from 12.55 – 14,47 kgcm2, wood kambang 25.10-31,11 kgcm2 and wood tarap 19.20- 24,18 kgcm2. As for Modulus of Elasticity (MoE) on the lua 1129,80- 2092,70 kgcm2, wood kambang 2512,37-3971,32 kgcm2 and tarap 2050,63-2691,09 kgcm2. Gypsum board are mechanical properties do not meet quality standards created SNI 03-6434-2000.Keywords: sawdust, lua, kambang, tarap, gypsum, mechanical


Author(s):  
Chernichkina A.D.

A large number of biologically active substances, organic acids, tannins, and pectin substances were detected during the study of fruits, leaves, and pulp of the fruits of mountain Ash. The content of these substances in leaves and pulp will significantly expand the arsenal of medicinal plant raw materials used. Given the wide distribution of mountain Ash in the territory of the Russian Federation, harvesting leaves from the same plants after harvesting the fruit and using pulp will make it possible to obtain new phytopreparations.


Food Industry ◽  
2020 ◽  
Vol 5 (2) ◽  
pp. 71-78
Author(s):  
Ekaterina Minnikhanova ◽  
Nataliya Zavorokhina ◽  
Anna Gilina

Abstract The inclusion of polysaccharide thickeners in the recipes of sweet dishes increases the functional reserves of the body, contributes to the preservation of health and the prevention of diseases. The purpose of the research is to study the sensory characteristics of polysaccharides of various nature when combined with food acids, to develop a recipe for a basic mixture of low-calorie meals for public catering. The authors analyzed citric, lactic and succinic acids in combinations with polysaccharides of various nature. Organoleptic tests were evaluated by a touch panel. The organization of the tasting analysis corresponded to GOST ISO 6658-2016; the consistency was determined according to GOST 31986-2012, GOST ISO 11036-2017, GOST ISO 8588-2011. The optimal organoleptic combinations of the presented food acids and complex additives of sweeteners (CDP) were identified, which included aspartame, sodium saccharinate, Sucralose, sweetness coefficient – 340: the mixture with citric acid had a long pleasant aftertaste without foreign tastes and the best taste characteristics. Using the “A-not A” method, we found that the sample with the addition of CDP is identical to the sucrose solution. In the second part of the study, polysaccharides were added to model samples of acids with complex sweeteners; the best sensory characteristics were obtained by model samples consisting of a mixture of low-esterified Apple pectin with lactic acid and KDP. The technology of obtaining a stable elastic jelly using low-esterified Apple pectin has been developed, since the complex mixture of sweeteners and food acids does not have a dehydrating effect. Developed a dry mix recipe that can serve as a basic development, low-calorie sweet products for catering and has a variance of use of lactic and succinic acids, depending on the flavor characteristics of the raw materials used and its corrective ability.


2020 ◽  
Vol 4 (2) ◽  
Author(s):  
Ivan Yulianto ◽  
Ario Seno Nugroho

An alternative strategy to reduce the trade balance deficit simultaneously to increase the net foreign exchange is the import-substitution for raw materials used to produce an export goods. This paper proposes an import substitution study on footwear products that have a dependency on imported raw materials by 70 percent, with the largest composition being leather raw materials by 67 percent. This paper analyzes the relationship between subsidies on the leather industry to leather import-substitution, multiplier effect to footwear sector, and Indonesia trade balance. Author make use of simulation the on Input-Output 2010 table and Computable General Equilibrium (CGE) Model. The simulation shows 100 billion subsidies on the leather sector, lead for the substitution-import of leather by 7,94 million rupiah, increase the net export foreign exchange by 1.1 billion rupiah of the footwear sector, and for overall, increase Indonesia trade balance deficit by 68 billion rupiah. Keywords: Computable General Equilibrium, footwear, leather, net foreign exchange, subsidy.ABSTRAK: Salah satu terobosan untuk mengurangi defisit neraca perdagangan dan meningkatkan nilai neto devisa ekspor adalah dengan substitusi impor bahan baku yang digunakan untuk memproduksi barang ekspor. Paper ini mengusulkan kajian substitusi impor pada produk alas kaki yang mempunyai ketergantungan bahan baku impornya sebesar 70 persen, dengan komposisi terbesar adalah bahan baku kulit sebesar 67 persen. Tujuan penelitian ini adalah untuk mengetahui dampak stimulus subsidi pada industri kulit terhadap subtitusi impor kulit, dukungan multiplier sektor kulit terhadap sektor alas kaki, serta terhadap devisa ekspor Indonesia. Penelitian ini menggunakan simulasi model Computable General Equilibrium (CGE). Hasil simulasi menunjukkan stimulus subsidi sebesar 100 milyar rupiah pada sektor kulit memberikan substitusi bahan baku kulit sebesar 7,94 juta rupiah, menaikkan devisa ekspor sektor alas kaki sebesar 1.1 miliar rupiah, serta secara keseluruhan menambah defisit neraca berjalan Indonesia sebesar 68 miliar rupiah. Kata kunci: alas kaki, Computable General Equilibrium (CGE), devisa ekspor, kulit, subsidi.


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