Application As Wall Tile Glazes with Sanitary (Bactericidal) Properties

Total Page:16

File Type:pdf, Size:1020Kb

Application As Wall Tile Glazes with Sanitary (Bactericidal) Properties CASTEU6:--: (SI'AI:>;) iI QUALI 98 DEVELOPMENT OF CERAMIC GLAZES WITH OPTICAL ABSORPTION AND EMISSION PROPERTIES: APPLICATION AS WALL TILE GLAZES WITH SANITARY (BACTERICIDAL) PROPERTIES M. T. Tichell"', A. Pascual'", J. Bakali"', V. Kozukharov'''', E. Cordrmcillo'"", P. Escribano"?', J. Ca rda'"'' " ESMA LTES, S. A., 12110, Alcorn (Spain) ''''University of Chem ical Technology and Metallurgy (Sofia (Bu lgaria) '''''Department of Organic and Inorganic Che m istry, Un ivers idad [aurne L 12080, Ca stellon . ABSTRACT TIl<' pn'sellt stlldy describes the derclopmcnt of a ceramic s la:e (frit), u-h ich 011 applicatioll exhibit» opticel propcrtics with a bactericidal tffect. The material obtained, compared to sim ilar <'XistillS products, present» intprorcd It'mr resistance ill st'rl'ice, hiS'1gloss and potential lise ill sanitari; products and ceramic tral! tiles. The materiai tms dnvloped "y selecting rare-earth oxides, 11'hose compatibility lms studied ill differC1lt frit formuunions, sl/"seqllellfly mcasurins; their absorption and etnission properties ill the ultmriolct to infrared radiation rallge. The properties ofthe materials obtained were clutmctcriscd and mntsured by UV and uisiblr absorption spectrophotometric techniques, emission (pltotolumincsccnt spectm m), alld infrared as trcll as nuclcur magnetic resOll/mce spectroscopic techniques ('"H IUvlN ). Structural, microstructurni nnd microannivticai studic» ll'en' also conducted 0 11 the prepared samples by X-my diffruction (X RO) and scanni ng electron microscopy (SEA'1) ill all instrument eql/ipped u-ith ellerSI! dispcrsir« X-ray inicroanalvsis (EOX). Finallu, the properties ll'en' assessed which the materials dt'l'eloped exhibited as finished products. These inrolrcd refractive properties (gloss) ami bactericidal capability, selectillS for tile latter case certain strains of bacteria (Scherichia coli, PSl'l/dOIll Olltl aeruginosa alld Stnfilococcus uureus ). and mlOlysillg the degrc«of growth or a/Isellce ofsrowtll of these colonies by optiCilI microscopy and image analusi«. p.Gr - 17 ill QUALI ~_ 98 CASTELLO:" (SPAI:" ) 1. INTRODUCTION At present a new field known as photochemistry is being developed in Solid State Chemistry. The research results not only have fundamental implications but also open up a vast potential of real technological applications. Recently "Progress in Inorgani c Chemistry" published a monograph entitled: "Molecular Level Artificial Photosynthetic Materials", dealing with aspects of the molecular nature of Chemistry and Materials Science in the field of artificial photosynthetic materials design, which can convert solar energy into other products that yield energy or directly in electricity. This requires integrating a variety of factors in the material that is developed. Such factors include light absorption, electron and I or energy transfer processes, and fina lly the obtainment of useful products with interesting properties"! The lite rature has traditi onall y described sensitised w ide-bandgap semicond uc tors'". Typical wi de-bandgap semicond uc tors are the n-types suc h as TiO" ZnO and SrTiO" which exhibit high stability, easy processibil ity, and do not decompose under radiati on . The se nsitisation process of a se micond uctor material involves an absorption capacity in a range of wavelengths exceed ing the ga p. Thi s phen omenon became known in 1873 following Vogel's!" invest igations into organic inks deposited on semicond uc tor halogen mineral gra ins, whe n he man aged to ra ise the photosynthet ic se nsitivity of these particles in low energy regions of the spectrum (visible region ). This system simply consists of an optically active molecule that can be exc ited electro nically, and on be ing ads orbe d onto the semicond uc tor surface allows introducing the excited electron into the conduction band, thus gene rating photoelectrochemi cal and photocatalyt ic processes. Vogel's work led to extensive research that has continued up to the present decadel'll5l l' l. These studies have produced important advances in the degree of understanding of the fundamental processes involved, such as degree of sensitisation, light absorption efficiency and development of single-layer manufacturing techniques. In recent years research has focused on TiO, production with nanoparticle sizes to raise speci fic surface area and increase the gap. Progress ha s also been made in developing new synthes is methods (sol-gel method s), and transparent film applications. This has allowed deveioping photoanodes and thin layer solar cells combine d with an appropriate photosen sitive pigment, thus achieving sunlight-electric ity conversion efficiencies of the order of 7 to 10 %. The literature!" reports numerous examples of molecul ar photosensitisers designed using TiO, with transition metal complexes, together with chlorophyll derivatives and natural porphyrins. These studies have led to a ne w line of research focused on synthesising [I }. " Prog ress ill Inorganic Chemistry" . Vol. 44 . Pu bli shed by : G. J. .MEYER, J OI L~ \ 'v'[LEY :\ :\ D S() \lS, Nue va York, 199 7. [Z]. c. A . B IG,\;OZZ I, K . R. Sc.:H()(Y\'OVER AND F. SCA.""HXJLA, "A <upramotecular approach 1£1 lig/II Iwn'e;; tillg an d: -eneitization of toide­ bandgap semiconductor» A l ltt' llllfl efft!cts and d targe separation" in Progress in Inorganic Chemistry Vol. 4-1. Published by: G. J. Meyer; John Wiley and Sons, Nueva York, 1997. (3). H . w. VOCEL , BER. Detscn. Chem. Ces. 6, 1302. (l873 ). HI· B. O 'RE:\GA:'-J Yrv1. G J<...\ TZH., Natu re (London), 353 , 73 7 (1991). [5). T. A .H EI\l FR, C A. BIG:\Olll YG. J. I\:lnER, J. PHYS. Quem., 97, 11987, (199 3 ). [6 ). R. ARGAllI, C A. BICr-..:0 77 I, T. A. H EJ ~l E R , E. x . C \SI EL L\\;O .-\~ D G. J. M r vre. l/lorg. Ofem, 33, 5741 , (199..1). [i ). A. K AY y :vt GR.\ TZEL, J. PH'fS. C hern., 97, 62n (1993). P. GI- 18 CASTELL6:-J (SPAI:'>: ) iii QUALI 98 semicond uctor pairs tha t exhibit different electronic gaps such as CdS-ZnO, CdSe-TiO" which exhibit non-linear optical properties"!"! A new method was developed by the Toto company, based on superhydrophilic photocatalytic tech nology (Honda-Fujishima effect invented by professor Honda and professor Fujishima of Tokyo University in the 70s, and patented by Toto). It has a bactericidal effect by capturing charge bearers. The optical excitation of electrons is produced by means of colloidal semiconductor particles having a high faul t density. The free bea rers are tra pped in the faults in which they undergo radiative and non-radiative recombination, as set out in the scheme: TiO, hv - TiO (ec• whe re ec• and h,. are free charge bea rers in the valence and conduction bands, and e, and h, are respectively the trapped electro ns and holes. In this fashion, the re arises a grea t charge accumulation in the minute stru cture of a semicond uctor colloid, which produces increased efficiency in interface red ox reactions on the colloid surface. This fact, cons isting of simultaneous ly trapping photogenerated holes and electrons ha s recen tly been demonstrated in colloidal TiO, sus pensions. Moreover, these trapped cha rge bearers exhibit characteristic absorption bands in the infrared and ultraviolet reg ions. Studies ha ve also been performed by trapping electrons in ZnO, WO, and SnO, colloids, investigating the photolysis phenom en on by laser tlashes. These expe riments have led to technology applications such as the development of photochromic matenals'''"! "! As an example, the photocatalysis ph enom enon consists of a semiconductor that breaks down organic compounds in wa ter or those in the air by oxidation through exposu re to light. On the other hand, the rare-earth oxides present electron transfer ba nds at f-f level transitions of levels. Fig. 1 schematically depicts interaction between photons (light) and matter. There are certain properties of electro n activity, which are desirable such as energy-level promotion of electrons, usually between the fundamental atomic state and a higher level. Such charge tra nsfer generally produces optical absorpti on phenomena in the visible and near UV spectrum, as well as emission phenom ena. This has allowed developing all the laser technology (ruby, Cr', RE" rare earths ). In rare ea rth and transition metals compo unds, the absorption bands can be attributed to electron transitions centred on individua l atoms having incom plete "d" or " f" leve ls. Thus the rare-earth oxides exhibit broad absorption ba nds in the visible spectrum, which indicate electron transfer un der low ene rgy conditions. (8]. D. LJL ~ r. v K \\ I.\ I, ]. Pit h . Che rn" 97, 10769 (199 3) , (91. E. Cor~Ol")" C I L tO. J. B. C .I, RO.-", x t . A : T F. '\ A, G. \-10 '-,-1<:1,) :-. .\ '<0 P. ESCRlfI" ",O, J. Sill-Cd Science ami Tcd llloh'S,u.S, to·B, (1997). [lOJ. C. S. T U:CHI " -,0 D. F. OLLI S, "Piw tocatalyf ic dt'gradatitlll {)f M-gmrh" '/'fi rer conm minaut-: lIIecllfllli"m" illi '(lllliIlS " .lIdro.\".1I1 radical attock", Jou rnal o f Catalvsis. 122, 178- 192 (1990). [111. .\1. R. H O FF\ IA .... <; S. T. ;.:' .... en-,,\\'. C HOJ A''0 D. W. B.\lIl B I:\:'\'\, "E nrirownen tat aFplicatio"" ~f-..cmiconductor ph (lll l (f1ta l y ~i ~ " . Chern. Rev, 95, 69-96, (1995) , P. GI · 19 iii QUALI ..L/f 98 CA5TELL6N (SPAI:',J) In thi s way, sensitised luminescence involves enabling the absorbed energy of an ion (sensitiser) in an absorp tion band to be em itted in the emission band of another ion (activator). Ene rgy transfer from the sensitiser to th e activator occu rs through the following types of transfer: emission-reabsorption, non-radiative resonant, and non­ radi ative non- resonant tra nsfer'!", CONDUCTION t Promotio n to the BANDGAP conduction band ~ f " ~ ! f~ iir;,:f, r .,,:;~y'1iiiI t Exciting \Promotion '0 ' he transfers valence band d-d t f-f ~ transfer "A "8 Figure 1.
Recommended publications
  • Colonial Archaeology: 070 333 Spring 2006 Prof C. Schrire Room 201
    Colonial Archaeology: 070 333 Spring 2006 Prof C. Schrire [email protected] Room 201/202 RAB Phone: 932 9006 Course Outline: This course will teach the rudiments of identification and analysis of colonial artifacts dating from about 1600-1900 AD. Our teaching collection includes a variety of ceramics, pipes, glass and small finds. The course if taught largely by supervision and not lectures. Students will sort collections, draw objects, measure objects and identify them according to numerous criteria. Course Requirements: A prerequisite for this course is 070: 208, Survey of Historical Archaeology, normally taught in the Fall term. Students for whom this requirement was waived are expected to study a suitable textbook on the subject, such as Orser, C. 1995 Historical Archaeology and Deetz, J In small things forgotten. Students will attend one three hour class, once a week. During this time they will handle material, analyze it, and draw objects. Each student will need a clean writing pad or notebook, a pad of graph paper, pencils, colored pencils, eraser, a ruler, and a divider. There will be two exams, a midterm and final. Useful Texts: 1. Noel-Hume, I. 2001. The Artifacts of Colonial America 2. Fournier, Robert. Illustrated Dictionary of Practical Pottery. Paperback, 4th ed. 2000 Radnor Pa. Available at Amazon.com ($31.96) 3. Numerous additional sources will be present at class for used during the practicals. Colonial Archaeology: 070 330 Significant technical terms: (see Fournier 2000) Absorption: The taking up of liquid into the pores of a pot. The water absorption of a ceramic is an indicator of its degree of vitrification.
    [Show full text]
  • Floor Tile Glass-Ceramic Glaze for Improvement of Glaze Surface
    Journal of the European Ceramic Society xxx (2006) xxx–xxx Floor tile glass-ceramic glaze for improvement of glaze surface properties Bijan Eftekhari Yekta a,∗, Parvin Alizadeh b, Leila Rezazadeh c a Ceramic Division, Department of Materials, Iran University of Science and Technology, Tehran, Iran b School of Engineering, Tarbiat Modaress University, Tehran, Iran c Ceramic Division, Materials & Energy Research Centre, Tehran, Iran Received 16 September 2005; received in revised form 4 December 2005; accepted 28 December 2005 Abstract Simultaneous improvement of surface hardness and glossiness of floor tile glaze, without changing its firing temperature, was the main purpose of the present paper. Thus, various glazes in the system of CaO–MgO–SiO2–Al2O3–ZrO2 were prepared and their crystallization behaviors within a fast firing cycle were investigated. With increasing amounts of calcium and magnesium oxides to base glass, the optimum glass-ceramic glaze was obtained. The results showed that with increasing of CaO and MgO part weights in frit, the crystallization peak temperature was gradually decreased and the intensities of diopside and zirconium silicate were increased. The comparison of micro hardness for the optimum glass ceramic glaze derived in this work with a traditional one used in floor tile industries indicates an improvement of 21%. It was found that the glaze hardness not only depend on the amount and type of crystalline phases, but also on the residual glass composition. Furthermore, it was observed that the glaze micro hardness is only slightly affected by thermal expansion mismatch of body and glaze. © 2006 Elsevier Ltd. All rights reserved. Keywords: Glass ceramic; Glaze 1.
    [Show full text]
  • Transparent Glazes for Porcelain Tile: Glassy and Glass-Ceramic Glazes with Cristobalite Crystallisations
    CASTELL6N (SPAIN) ' QUALI ~ 2 00 2 TRANSPARENT GLAZES FOR PORCELAIN TILE: GLASSY AND GLASS-CERAMIC GLAZES WITH CRISTOBALITE CRYSTALLISATIONS Sanc' hez- M unoz- , L"J,C a b rera M .J.," 'J FA00 ."'J, Be It ran' H "J., Car d a J..B "J ,'J Dept of Inorganic and Organ ic Chem istry, Un iversitat [aume I, Caste1l6n ("JVid res S.A., Villarreal. Caste1l6n ABSTRACT As result of the collabora tion betuieen the compallY Vidres S.A. mid the Dept. ofInorganic and Organic Chemistry of Unioersitat [aume I of Castellon, frits have beell developed ofa glassy and glass-ceramic nature (with crustallisation ofchemically stabilised -cristobalite), which call be used ill transparent glaze compositionsfor porcelain tile, with the possibility ofpolishing. Both the glassy and the glass-ceramic glazes have beell developed ill the system SiO,-AI,O,-B,O,-CaO-ZIlO-Na,O­ K,O-BaO-SrO with contents ill SiO, up to 73 wt%, using raw materials typically found ill the ceramic indusiru. Cnjs tutlisation of cristobalite of composition Si'.xAI,Sr'i'O, mid Si,.,AI,Ca,/,O, takes place by heterogeneous nucleation at the glaze surface and at the fr it particle COil tact points, growillg fi rst as regular isolated crystals and then as dendritic crystals, ill which case thelj call OCCll py large surfaceareas of theglaze. The glazes developed, ill which thesefrits are the[undamental component, haoe higher mechanical properties with regard to hardness, resistance to abrasion. acids and stains than contentional transparent glazes alld the porcelain tile polished surface. P.GI- 239 CA STELL6 :--1 (SPAJ:--I j 1.
    [Show full text]
  • Development of a Glass-Ceramic Glaze Formulated from Industrial Residues to Improve the Mechanical Properties of the Porcelain Stoneware Tiles
    ABSTRACT TO THE WORKSHOP: VITROGEOWASTES, Elche, sept 2017 Development of a glass-ceramic glaze formulated from industrial residues to improve the mechanical properties of the porcelain stoneware tiles. E. Barrachina1, M. Esquinas2, J. Llop2, M.D. Notari2, J.B. Carda1 1 Department of Inorganic and Organic Chemistry, Universitat Jaume I, Castellón, 12071 (Spain) 2 Superior School of Ceramic in l´Alcora, Castellón 12110 (Spain) ABSTRACT In this research a mixture of 90%wt of industrial residues (recycled soda-lime glass and ashes from a coal power thermal plant) have been vitrified for their use as “secondary raw material”. Then, a glaze suspension was prepared to be applied as a glaze suspension on the porcelain stoneware tile. The tested pieces have been fired by a conventional porcelain cycle at 1180ºC of maximum temperature. The XRD, XRF, SEM/EDS and the dilatometric analysis have been the instrumental techniques used to characterize the final material. Finally, an ecological glass-ceramic glaze perfectly fitting on porcelain ceramic tile has been produced, exhibiting a unique phase, anorthite, which ensures a high flexural strength (around 96 MPa) and a significant Vickers microhardness of 250 GPa, improving the mechanical properties of a conventional the porcelain ceramic tile. Keywords Circular economy, revalorization of industrial waste, glass-ceramic glaze, porcelain stoneware, mechanical properties 1. Introduction Citizen environmental awareness has increased in the past decade, due to the publication of many studies on the impacts of environmental degradation. In that sense, scientific research is contributing to arouse public awareness about the new technological challenges in society. One of the concepts which at the moment seems to be proliferating in a significant way is the circular economy.
    [Show full text]
  • Rustoleum Tub and Tile Refinishing Kit Directions
    Rustoleum Tub And Tile Refinishing Kit Directions Is Weylin missive when Giffy follows fuliginously? Rodge liberalises ashore while eightpenny Raj weaves Gallice reinventor gelatinate wrathfully, anxiously. is Prasun Unnavigated Pythian? and fractured Timotheus syncretizes her renting discard dubiously or Follow all of paint been reimagined, there are a painting your account for my bathtub kit. Everyone in love our tile rustoleum tub under no refinishing kit in protective finish or. Loyal nanaimo bathtub post of paint cans together to get this? Really mean really well that time just about this is easier solution that this diy paint is a container did you only a experimentar. Some actions you had help all unused materials to care to tile tub and installation cost. Set the end of porcelain and that my bathroom again shortly after a kitchen and ask your tile kit click to the tub gets less expensive if. Combine colours in my landlord had to keep windows, dingy next steps! Itsepoxy chemistry is also be bound by: i do you do the back to remove your brushes for rustoleum tub and tile refinishing kit again with the home improvement over the! She explores her enthusiasm for sure to this. They can choose something that this is an eye wear contacts, get about an hour between. What did you sand paper craft paint a tub and tile rustoleum tub were super disappointed to refinish a week i noticed blisters on the! Sharing a project for bedrooms, then it would love all directions state, see stroke patterns must be dangerous? Then i wrapped around the good news for convenience only paint last time that is durable stuff! Superior performance for.
    [Show full text]
  • High Lead Exposures Resulting from Pottery Production in a Village in Michoacaân State, Mexico
    Journal of Exposure Analysis and Environmental Epidemiology (1999) 9, 343±351 # 1999 Stockton Press All rights reserved 1053-4245/99/$12.00 http://www.stockton-press.co.uk High lead exposures resulting from pottery production in a village in MichoacaÂn State, Mexico ROBIN HIBBERT,a ZHIPENG BAI,b JAIME NAVIA,c DANIEL M. KAMMENa,d AND JUNFENG (JIM) ZHANGb a Science, Technology and Environmental Policy (STEP) Program, Woodrow Wilson School of Public and International Affairs, Princeton University, Princeton, New Jersey 08544-1013 b Environmental and Occupational Health Sciences Institute, UMDNJ-Robert Wood Johnson Medical School and Rutgers University, 170 Frelinghuysen Road, Piscataway, New Jersey 08854 c Grupo Interdisciplinario de TecnologIÁa Rural Apropiada (GIRA), AC, Apartado Postal 158, PaÂtzcuaro, MichoacaÂn 61609, Mexico d Energy and Resources Group (ERG), University of California, Berkeley, Berkeley, California 94720-3050 This paper reports findings from a screening study conducted to examine potential lead (Pb) exposures in residents of a Mexican village where Pb oxide continues to be used in ceramic pottery production. Extremely high Pb concentrations were measured in personal and indoor air samples, household surface dust samples, and household soil samples. Personal air Pb concentrations for workers performing pottery firing and glazing were up to 454 g/m3. Results from indoor air samples indicate that airborne Pb concentrations were lower during nonglazing period compared to the glazing period. Soil Pb concentrations measured in 17 homes ranged from 0.39 to 19.8 mg/g. Dust Pb loading on surfaces of household items, hands, and clothes of a worker ranged from 172 to 33 060 g/f t 2.
    [Show full text]
  • Thin Section Petrography for Ceramic Glaze Microstructures
    minerals Commentary Breaking Preconceptions: Thin Section Petrography For Ceramic Glaze Microstructures Roberta Di Febo 1,2,3,*, Lluís Casas 4 , Jordi Rius 5, Riccardo Tagliapietra 6 and Joan Carles Melgarejo 7 1 Dept. de Ciències de l’Antiguitat i Edad Mitjana, Facultat de Filosofia i Lletres, Universitat Autònoma de Barcelona (UAB), Edifici B, 08193 Bellaterra, Spain 2 Institut Català d’Arqueologia Clàssica (ICAC), Unitat d’Estudis Arqueomètrics (UEA), Plaça d’en Rovellat, s/n, 43003 Tarragona, Spain 3 U Science Tech, MECAMAT group, University of Vic—Central University of Catalonia, C. De la Laura 13, 08500 Catalonia, Spain 4 Departament de Geologia, Universitat Autònoma de Barcelona, 08193 Bellaterra, Spain; [email protected] 5 Institute de Ciència de Materials de Barcelona (ICMAB-CSIC), Campus de la UAB, 08193 Bellaterra, Spain; [email protected] 6 Renishaw S.p.A Via dei Prati 5, 10044 Pianezza (TO), Italia; [email protected] 7 Departament de Mineralogia, Petrologia i Geologia Aplicada, Facultat de Ciències de la Terra, Universitat de Barcelona, Martí i Franquès s/n, 08028 Barcelona, Spain; [email protected] * Correspondence: [email protected] or [email protected]; Tel.: +34-977-249-133 Received: 16 December 2018; Accepted: 12 February 2019; Published: 15 February 2019 Abstract: During the last thirty years, microstructural and technological studies on ceramic glazes have been essentially carried out through the use of Scanning Electron Microscopy (SEM) combined with energy dispersive X-ray analysis (EDX). On the contrary, optical microscopy (OM) has been considered of limited use in solving the very complex and fine-scale microstructures associated with ceramic glazes.
    [Show full text]
  • Chairside Zirconia Is Here Clinical Flexibility and Predictability for CEREC Dentists
    INTRODUCING Abutment Solutions For customized implant restorations fabricated with CEREC® technology Digital all around. The complete solution from temporary to final restoration • Total abutment solution Optimally® cementedHybrid Abutment with • Accurately fitting restorations due to the digital manufacturing process Multilink • Stable bond using Multilink® Hybrid Abutment Cement 100% CUSTOMER SATISFACTION GUARANTEED! ivoclarvivadent.com Call us toll free at 1-800-533-6825 in the U.S., 1-800-263-8182 in Canada. © 2016 Ivoclar Vivadent, Inc. Ivoclar Vivadent, Telio and IPS e.max are registered trademarks of Ivoclar Vivadent, Inc. CEREC® is a registered trademark of Sirona Dental Systems, Inc. 8942_AD.indd 1 12/28/15 10:37 AM Dear Friends: Thank you for reading this special digital supplement of cerecdoctors.com magazine focusing on the new zirconia solution by Dentsply Sirona. Our aim is to provide you with an overview of the entire process of fabricating zirconia restorations chairside with the CEREC system. For more detailed information, please visit www.cerecdoctors.com/oven where you can watch videos on each step of the process of fabricating zirconia with the CEREC system. The video series is intended to guide all users on techniques, protocols and required equipment. The ability to fabricate zirconia with CEREC in a single appointment is certainly an exciting advancement for CEREC users, and therefore, we will be including this workflow in our upcoming seminar, Treating Comprehensive and Esthetic Cases With a Digital Workflow. As always, cerecdoctors.com remains at the forefront of providing the most current information to all CEREC users. With our team of clinicians and contributors, and our strong partnership with Dentsply Sirona, you can be sure that we are committed to keeping CEREC users engaged and informed on all things CEREC.
    [Show full text]
  • Achieving Opacity in Ceramic Tiles: Microstructural and Spectrophotometric Analysis
    CASTELL6N (SPAIN) Dt QUALILa?L 2004 ACHIEVING OPACITY IN CERAMIC TILES: MICROSTRUCTURAL AND SPECTROPHOTOMETRIC ANALYSIS Santos?', C.R.; Fontana?', T.L.B.; Uggioni'", E.; Riella(2), H.G.; Bernardin?', A.M. (1) Departamento de Engenharia de Materiais; Departamento de Matematica Universidade do Extremo SuI Catarinense - UNESC Avenida Universitaria 1105; 88806-000; Criciuma, SC, Brazil [email protected] (2) Departamento de Engenharia Qufrnica Universidade Federal de Santa Catarina - UFSC Campus Universitario: 88040-900; Florian6polis, SC, Brazil [email protected] ABSTRACT A majorfactor in obtaining stablecolours in ceramic tiles is the use of agents that can cause opacity in transparent enamels. These agents are used as additives in enamel preparation, and the control of their effect during firing is fundamental, due the possible elimination or reduction of tonality variation during processing. The most widely used agents to cause opacity are zirconia (zirconium silicate: ZrSi04) and rutile (titanium oxide: Ti02). Particle size, refraction index and volumetric fraction of the opacifying agent being used affect the enamel degree of opacity. This work therefore aims to evaluate the influence of the zirconia mass fraction on the opacity of a transparent enamel, based on microstructural aspects, mainly particle dispersion in the glaze matrix. A transparent frit for single firing was used; thefrit was milled in a laboratory jar mill (# 325 mesh) and fine zirconia was added (1% to 24%; mass fraction). The glazes obtained were homogenized (5min; jar mill) and compacted (25MPa) in cylindrical samples with wax (10% weight). The pressed samples were sintered (1100°C; 5min) after a dewaxing process. After sample preparation, microstructural (SEM and OM) and spectrophotometric analysis was carried out.
    [Show full text]
  • Unearthing the Chemistry of Ceramic Glazes
    Ouachita Baptist University Scholarly Commons @ Ouachita Honors Theses Carl Goodson Honors Program 2016 Creating Color: Unearthing the Chemistry of Ceramic Glazes Jessica Mariah Hargis Ouachita Baptist University Follow this and additional works at: https://scholarlycommons.obu.edu/honors_theses Part of the Ceramic Arts Commons, Chemistry Commons, and the Painting Commons Recommended Citation Hargis, Jessica Mariah, "Creating Color: Unearthing the Chemistry of Ceramic Glazes" (2016). Honors Theses. 218. https://scholarlycommons.obu.edu/honors_theses/218 This Thesis is brought to you for free and open access by the Carl Goodson Honors Program at Scholarly Commons @ Ouachita. It has been accepted for inclusion in Honors Theses by an authorized administrator of Scholarly Commons @ Ouachita. For more information, please contact [email protected]. 1 Introduction There is something magical about taking lumps of cold clay and turning them into a functional form. The transformation process is what first peaked my interest in ceramics. I turned to this visual art form my junior year of college after being completely overwhelmed by my chemistry major. Not only did Ceramics 1 teach me basic hand building and surface design techniques, but it allowed me to literally pound out my stress. I've gained a strong adoration for ceramics because it relieves my stress and gives me the opportunity to express myself. After taking Ceramics 1, enrolling in Ceramics 2 was a no-brainer. The second course was all about learning how to throw on a wheel. Using the pottery wheel permitted me to make more refined and symmetrical forms. Ceramics 2 was even more enjoyable for me, because I was able to make functional kitchen ware forms like bowls, mugs, and casserole dishes.
    [Show full text]
  • Using Optical Coherence Tomography to Characterize the Crack Morphology of Ceramic Glaze and Jade
    13 Using Optical Coherence Tomography to Characterize the Crack Morphology of Ceramic Glaze and Jade M.-L. Yang, A.M. Winkler, J. Klein, A. Wall and J.K. Barton Tamkang University, Taipei, Taiwan 1. Introduction The utilization of optical coherence tomography (OCT) in artworks’ examination for the past several years has confirmed its feasibility (Elias et al., 2010; Targowski, 2008). The results not only aid authentication of museum collections, but also provide crucial information for understanding artworks’ manufacturing technology and use history, as well as for continuing preservation. To display certain characteristics of ceramic glaze and jade materials, such as components assemblage, bubbles distribution, glaze-layer structure, cracks morphology and alteration phenomenon, OCT is an ideal tool. In previous research, the bubble distribution and components assemblage within Chinese glaze samples has been discussed (Yang et al., 2011, 2009), and the alteration of archaic jade has also been examined (Liang et al., 2008; Yang et al., 2004). In addition, with specific algorithm programs, the researcher is also able to obtain quantitative data, such as the bubble size and number in a glaze or intensities of texture vector in a jade material (Klein et al., 2011; Chang et al., 2010). In the present chapter, various cracks’ morphology in Chinese glaze and jade samples are described and characterized using OCT systems. Cracks are common in brittle materials, such as traditional glass, ceramics, or even tougher semi-gem or rock. In general, they are regarded as defective in artistic or industrial products. However, certain cracks were endowed with an artistic or cultural attribute or significance because of their special morphology and uniquely formed patterns.
    [Show full text]
  • Titanium Oxide Photocatalytic Materials and Their Applications in Ceramics
    Ceramic Sciences and Engineering (2018) Original Research Article Titanium Oxide Photocatalytic Materials and Their Applications in Ceramics Zhigang Chen,Hao Liu,Jianwei Su School of Materials Science and Engineering, Chengdu Jiaotong University, Sichuan, China ABSTRACT Titanium oxide has the advantages of high activity, good stability, non-toxic and low cost cost eff ective. It is one of the most widely studied photocatalysts and the most promising material for photocatalytic ceramics. In this paper, the photocatalytic mechanism of TiO2, the influence factors of photocatalytic activity, the preparation of nano- TiO2, the phase change of nano-TiO2, the application of TiO2 photocatalytic materials and the research progress of photocatalytic ceramics were reviewed. KEYWORDS: titanium oxide; photocatalysis; ceramics; application 1. Introduction In 1972, Japanese scholars Fujishima and Honda discovered that photocatalytic decomposition of water can be done in the semiconductor TiO2 electrode to prepare hydrogen [1]. TiO2 photocatalytic technology has aroused great interest of science and technology workers ever since [2-9]. In 1976, Canadian scientists along with other studies done had discovered that under the ultraviolet light irradiation, nano-TiO2 may decompose the organic compounds biphenyl and chlorinated biphenyl [10]. With the increasingly prominent energy and environmental problems, semiconductor photocatalytic technology has unprecedentedly received an extensive global attention and achieved rapid development [11-14]. At present, the most widely studied semiconductor photocatalysts are n-type semiconductor compounds [12, 15- 21], such as: TiO2, ZnO, CdS, ZnS, MoO3, WO3 and others. Of all, TiO2 has been the most favorable semiconductor compound chosen for its high catalytic activity, good stability, non-toxic and cost effective advantages [22-26].
    [Show full text]