Materials Science and Applied Chemistry最新文献

{"title":"Celtniecības keramika, keramzīts un keramiskie sorbenti","authors":"Ruta Švinka, Visvaldis Švinka","doi":"10.7250/MSAC-2018-0002","DOIUrl":"https://doi.org/10.7250/MSAC-2018-0002","url":null,"abstract":"Vēsturiski viena no silikātu tehnoloģijas katedras pamattēmām vienmēr ir bijusi celtniecības materiālu pētīšana un jaunu materiālu izstrāde. Tie ir gan keramikas materiāli, gan materiāli uz neorganisko javu saistvielu bāzes. Ir analizētas un salīdzinātas šo materiālu īpašības: siltuma vadāmība, līdzsvara mitrums, mehāniskās īpašības. Salīdzinātas rūpnieciskos apstākļos un laboratorijā iegūtu dažādu Latvijas mālu keramikas materiālu īpašības un struktūra. Aprakstīta dažu rūpniecisko atkritumu ietekme uz keramikas materiālu īpašībām. Aprakstīta arī jauna keramikas materiāla keramzīta ražošanas tehnoloģija – vienas stadijas paņēmiens, kas ļauj paplašināt keramzīta ražošanai izmantojamo izejvielu bāzi un variēt keramzīta īpašības atkarībā no paredzamā pielietojuma. Pētīta dažādu Latvijas mālu noderība porainu keramisku sorbentu iegūšanai, par poru veidotājiem izmantojot organiskas dabas ražošanas atkritumus. Analizēta keramikas virsmas apstrāde, piemēram, apstarošana ar paātrinātajiem elektroniem un nanodaļiņu pārklājumi, keramikas granulu sorbcijas spējas palielināšanai un noderība fotokatalītiskai organisku piesārņotāju sadalīšanai.Building Ceramics, Expanded Clay, and Ceramic SorbentsInvestigation and development of new building materials historically was one of base research fields in the Institute of Silicate Materials. These are ceramic materials and materials based on inorganic binders. These materials have both advantages and disadvantages. Properties of these materials, such as thermal conductivity, equilibrium humidity and mechanical properties, are analysed and compared. Properties and structure of ceramic materials produced from Latvian clays in the laboratory and industrially were compared. Influence of addition of some industrial waste on the properties of ceramic materials was described. A new technology for obtaining expanded clay pellets was developed. It is a one-step technology that makes it possible to extend the basis of raw materials for production of expanded clay pellets and to produce pellets with different properties depending on the possible practical use. Usefulness of different Latvian clay for the production of porous ceramic sorbents was investigated. Organic industrial waste was added to function as pore former. A treatment of ceramic surface by irradiation with accelerated electrons or coating with nanoparticles was analysed. An increase of sorption activity of ceramic pellets or usefulness for the photocatalytic decomposition of organic pollution was the goal of the aforementioned treatment.Keywords – ceramics, expanded clay, equilibrium moisture, thermal insulation, ceramic granules, sorbents.","PeriodicalId":18239,"journal":{"name":"Materials Science and Applied Chemistry","volume":"18 5","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91484399","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Blīva augsttemperatūras mullīta-ZrO2 keramika","authors":"G. Sedmale, Uldis-Jānis Sedmalis, Ingunda Šperberga, Māris Rundāns","doi":"10.7250/msac-2018-0005","DOIUrl":"https://doi.org/10.7250/msac-2018-0005","url":null,"abstract":"Parādīta piedevu (mālu minerāla – illīta, Si3N4, SiAlON), kā arī izejas pulveru izstrādes veida ietekme uz mullīta-ZrO2 keramikas saķepināšanas procesu (pielietojot tradicionālo saķepināšanas procesu un plazmas izlādes saķepināšanas procesu jeb SPS), fāžu sastāvu, struktūru, mehāniskajām un keramiskajām īpašībām.Mālu piedeva sekmē pulvera  daļiņu  izmēru  samazināšanos,  veicina  keramikas paraugu sablīvēšanos tradicionālā saķepināšanas procesā, bet dod pretēju efektu, pielietojot SPS procesu. Silīcija  nitrīda un  SiAlON nanopulveru  piedevas ir efektīvas SPS procesā, sasniegta paraugu spiedes izturība ap 600 MPa Si3N4 piedevas gadījumā, termiskā trieciena izturību un elastības moduļa  vērtības 180 – 220 GPa, kuras termiskā trieciena 1000/20 °C rezultātā samazinās pieļaujamās robežās. Šīs vērtības ir par aptuveni 20–25 % zemākas, pielietojot SiAlON piedevu.Keramikas paraugu, kas saķepināti tradicionāli un pielietojot SPS procesu, mikrostruktūrā ir mullīta vai pseidomullīta kristāliski veidojumi ar ieslēgtiem ZrO2 graudiem, kas pārsvarā ir kubiskā modifikācijā. Galvenā atšķirība starp abos saķepināšanas procesos iegūtajiem paraugiem ir tā, ka tradicionāli saķepināto paraugu mikrostruktūrā ir novērojama ‘tukšumu’ veidošanās, kuri aizpildās ar mullīta kristāliem, it sevišķi palielinoties Si3N4 piedevai. Mikrostruktūra keramikas paraugiem, kas saķepināti ar SPS tehnoloģiju ir blīvāka – mullīta kristāli ir blīvi izvietojušies, un tiem nav mullītam raksturīgās prizmatiskās formas.Dense high-temperature mullite-ZrO2 ceramicsThe influence of some additives (clay mineral illite, Si3N4, SiAlON) and the processing of the initial powders on sintering of mullite-ZrO2 ceramics (using traditional or plasma dispersion sintering processes), composition, structure, mechanical and ceramic properties of phases is shown.The clay additive contributes to the reduction of the particle size of the powder, facilitates the densification of the ceramic samples in the traditional sintering process, but vice versa if SPS is used. Silicon nitride and SiAlON nanopowder additives are effective in the SPS process; samples reach a compressive strength of approximately 600 MPa in the case of Si3N4 additive; thermal shock resistance and elastic modulus are in the range of 180–220 GPa, which under a thermal shock of 1000/20 °C will reduce within the permissible limits. These values are about 20–25 % lower if SiAlON additive is used.The microstructure of the ceramic samples traditionally sintered or sintered using a SPS process is formed by crystalline mullite or pseudomulite crystals with enclosed ZrO2 grains that mostly are in the cubic modification. The main difference between the samples obtained in both sintering processes is that formation of voids filled with mullite crystals can be observed in the microstructure of traditionally sintered samples, especially if the amount of Si3N4 additive is increased. The microstructure of the ceramic samples sintered with SPS technology is ","PeriodicalId":18239,"journal":{"name":"Materials Science and Applied Chemistry","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82979169","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Characterization and Applications of Organic Coagulant KOHIDRAC","authors":"Jūlija Karasa, J. Kostjukovs, S. Grinberga","doi":"10.1515/msac-2017-0007","DOIUrl":"https://doi.org/10.1515/msac-2017-0007","url":null,"abstract":"Abstract Low cost, effective and water soluble organic coagulant is offered for the extraction of charged clay particles. Coagulation with KOHIDRAC results in simultaneous concentration and purification of the clay fraction. After treatment with KOHIDRAC the obtained clay samples were free of carbonates and feldspar. Moreover, the amount of quartz decreased significantly in finished samples. The proposed coagulant and the patented methodology can be successfully used as purification procedure or as pretreatment for qualitative and quantitative analysis of clay minerals. The possible structure of the active compound KOHIDRAC was investigated in this paper. Real applications of the coagulant were provided.","PeriodicalId":18239,"journal":{"name":"Materials Science and Applied Chemistry","volume":"51 1","pages":"45 - 49"},"PeriodicalIF":0.0,"publicationDate":"2017-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78297238","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Liquid Membrane System for Extraction and Electrodeposition of Lead(II) During Electrodialysis","authors":"T. Sadyrbaeva","doi":"10.1515/msac-2017-0004","DOIUrl":"https://doi.org/10.1515/msac-2017-0004","url":null,"abstract":"Abstract A novel method for lead(II) removal from aqueous acidic solutions is presented. The method involves electrodialysis through bulk liquid membranes accompanied by electrodeposition of metal from the cathodic solution. Solutions of di(2-ethylhexyl)phosphoric acid with admixtures of tri-n-octylamine in 1,2-dichloroethane were used as the liquid membranes. The effects of the main electrodialysis parameters as well as of the composition of the liquid membranes and aqueous solutions on the lead(II) transport rate are studied. The optimal conditions are determined. A possibility of effective single-stage transfer of lead(II) through the liquid membrane into dilute solutions of perchloric, nitric and acetic acids is demonstrated. Dense and adherent lead electrodeposits are obtained from perchloric acid solutions. Maximum extraction degree of 93 % and electrodeposition degree of ~60 % are obtained during 5 h of electrodialysis.","PeriodicalId":18239,"journal":{"name":"Materials Science and Applied Chemistry","volume":"35 1","pages":"29 - 33"},"PeriodicalIF":0.0,"publicationDate":"2017-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73827390","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Synthesis, Characterization and Synthetic Applications of Fly-ash:H3PO4 Nanocatalyst","authors":"S. J. Joseph, K. Ranganathan, R. Suresh, R. Arulkumaran, R. Sundararajan, D. Kamalakkannan, S. P. Sakthinathan, G. Vanangamudi, S. Dineshkumar, K. Thirumurthy, I. Muthuvel, G. Thirunarayanan, K. Viveksarathi","doi":"10.1515/msac-2017-0002","DOIUrl":"https://doi.org/10.1515/msac-2017-0002","url":null,"abstract":"Abstract The solid acidic nanocatalyst fly-ash:H3PO4 was prepared and characterized by FT-IR, SEM, EDS and TEM analysis. This catalyst was utilized for aldol condensation, coupling and cyclization reaction. The effect of catalytic activity of this fly-ash:H3PO4 nanocatalyst was studied with the obtained yield of products under solvent-free conditions. In this synthetic reaction the obtained yields were more than 95 %.","PeriodicalId":18239,"journal":{"name":"Materials Science and Applied Chemistry","volume":"88 1","pages":"12 - 20"},"PeriodicalIF":0.0,"publicationDate":"2017-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76826331","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Glass Formation and Crystallization in P2O5-Nb2O5-CaO-Na2O System","authors":"A. Stunda-Zujeva, J. Vecstaudža, G. Krieke, L. Bērziņa-Cimdiņa","doi":"10.1515/msac-2017-0003","DOIUrl":"https://doi.org/10.1515/msac-2017-0003","url":null,"abstract":"Abstract There is a lack of studies on a wide composition range for calcium phosphate glasses containing transition elements, e.g. niobium. Addition of Nb2O5 increases mechanical and chemical strength of calcium phosphate glasses and glass ceramics. Glass is formed in a wide range of compositions. CaO promotes batch melting. The oxidation state of niobium has important role in glass forming. Solid state reactions between P2O5 and Nb2O5 during batch melt change the oxidation state of niobium. Nb5+ in this system acts as an intermediate or conditional glass former (glass is yellow) while Nb4+ is a glass modifier (glass is blue). It is possible to obtain glass with Nb2O5 (Nb5+) content up to 70 mol%. The glass ceramics obtained by reheating powdered glass contained niobium in crystalline phases. The composition of crystalline phases depends on the phosphate amount.","PeriodicalId":18239,"journal":{"name":"Materials Science and Applied Chemistry","volume":"62 1","pages":"21 - 28"},"PeriodicalIF":0.0,"publicationDate":"2017-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88714946","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"ZnFe2O4 Containing Nanoparticles: Synthesis and Magnetic Properties","authors":"I. Zalite, G. Heidemane, A. Krumina, D. Rašmane, M. Maiorov","doi":"10.1515/msac-2017-0006","DOIUrl":"https://doi.org/10.1515/msac-2017-0006","url":null,"abstract":"Abstract Solid solutions of Co1−xZnxFe2O4 and Ni1−xZnxFe2O4 (0 < x < 1) nanoparticles were synthesized by sol-gel self-propagating combustion method. The obtained single cubic phase product has a specific surface area 25 m2∙g−1 to 33 m2∙g−1 and crystallite size 25 nm to 40 nm. Lattice parameters change linearly from 8.371 A (CoFe2O4) and 8.337 A (NiFe2O4) to 8.431 A (ZnFe2O4). The saturation magnetization (Ms) changes non-linearly from 60.8 emu∙g−1 (CoFe2O4), respectively, from 35.6 emu∙g−1 (NiFe2O4) to 3.3 emu∙g−1 (ZnFe2O4) reaching maximal value 76.1 emu∙g−1 for Co0.8Zn0.2Fe2O4 and 64.9 emu∙g−1 – for Ni0.6Zn0.4Fe2O4.","PeriodicalId":18239,"journal":{"name":"Materials Science and Applied Chemistry","volume":"1 1","pages":"38 - 44"},"PeriodicalIF":0.0,"publicationDate":"2017-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88579837","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Facile Synthesis of Spinel Nanocrystalline ZnFe2O4: Enhanced Photocatalytic and Microbial Applications","authors":"P. Suppuraj, G. Thirunarayanan, M. Swaminathan, I. Muthuvel","doi":"10.1515/msac-2017-0001","DOIUrl":"https://doi.org/10.1515/msac-2017-0001","url":null,"abstract":"Abstract Spinel ZnFe2O4 was developed successfully as a heterogeneous-Fenton catalyst for the degradation of Reactive Yellow 86 (RY 86) under UV light. The ZnFe2O4 was characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), field emission scanning electron microscopy (FE-SEM) and UV-diffuse reflectance spectroscopy (UV-DRS). FE-SEM reveals that the some of the particles sizes are in the range from 10 nm to 50 nm. The photocatalytic performance of ZnFe2O4 was evaluated by degradation of RY 86 dye solution under UV light. The degradation rate was highly influenced by pH, initial concentrations of H2O2 and catalyst concentration. The results indicated that ZnFe2O4 could be used as a photocatalyst for treatment of industrial coloured wastewater. The catalyst was reused for five consecutive runs without significant change in its activity. Moreover, the antibacterial effects were investigated.","PeriodicalId":18239,"journal":{"name":"Materials Science and Applied Chemistry","volume":"78 1","pages":"11 - 5"},"PeriodicalIF":0.0,"publicationDate":"2017-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86178907","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Mechanical and Heat Shrinkable Properties of Electron Beam Irradiated Polypropylene With Bisphenol A Dimethacrylate Crosslinker","authors":"Z. Roja, I. Reinholds, J. Zicans, R. M. Meri","doi":"10.1515/msac-2017-0005","DOIUrl":"https://doi.org/10.1515/msac-2017-0005","url":null,"abstract":"Abstract Radiation crosslinking of polyolefins has gained interest for the development of advanced heat-shrinkable materials. Propylene homopolymer (PP1), polypropylene-polyethylene block copolymers (PP2, PP3) and their mixtures with 3 wt.% of bisphenol A dimethacrylate (BPDMA) crosslinking agent were irradiated with 25–150 kGy of accelerated electrons and were compared for aforementioned purpose. The studied mechanical properties indicated increased elongation in the presence of BPDMA that was contributed to the crosslinked moieties of PP and the crosslinking agent. The shrinkage stresses were comparable to that of polyethylene based heat-shrinkable material.","PeriodicalId":18239,"journal":{"name":"Materials Science and Applied Chemistry","volume":"12 1","pages":"34 - 37"},"PeriodicalIF":0.0,"publicationDate":"2017-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73896027","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Application of Anaerobic Digestate as Inoculum for Treatment of the Plant-Derived Wastes: Case Study","authors":"Kristine Kalneniece, A. Bērziņš, Z. Petriņa, K. Ruģele, Elīna Salava, Karlis Svirksts, M. Grube, V. Nikolajeva, O. Mutere","doi":"10.1515/msac-2017-0008","DOIUrl":"https://doi.org/10.1515/msac-2017-0008","url":null,"abstract":"Abstract The aim of this study was to characterize the digestate from an activated sludge biogas reactor (IDARS) as an inoculum for enzymatic hydrolysis and biogas production from organic wastes. Aerobic and anaerobic bacteria are represented in IDARS with H’ index 3.1 and 2.5, respectively. IDARS stimulated the enzymatic hydrolysis of wood and leaves, preferably broadleaf tree species. The results demonstrated the potential of IDARS for improvement of the technological parameters for conversion of organic wastes into biogas.","PeriodicalId":18239,"journal":{"name":"Materials Science and Applied Chemistry","volume":"2 1","pages":"50 - 58"},"PeriodicalIF":0.0,"publicationDate":"2017-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76832805","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}