Architectural Glazed Tiles Used in Ancient Chinese Screen Walls (15th–18th Century AD): Ceramic Technology, Decay Process and Conservation

The glazed tile is an important building material used throughout the history of traditional Chinese architecture. Architectural glazed tiles used to decorate the screen walls of ancient China are studied scientifically for the first time. More than 30 glazed tile samples from the screen walls of the 15th to 18th century AD of the Hancheng Confucian Temple and Town God’s Temple in Shaanxi Province were carefully investigated using SEM–EDS and XRD. Microstructure and chemistry indicated the raw materials, the recipes and the technological choices used to produce the paste and glaze of the glazed tile samples studied. The causes for the key degradation processes of these glazed tiles used as building materials in the screen walls have also been discussed. This work has clear implications for the restoration and conservation treatments on these kinds of ancient Chinese building materials.

EDITORIAL

From the theoretical point-of-view, the azulejo has been studied in Portugal since the second half of the nineteenth century through a perspective that increasingly highlights the idea of originality and, more recently, the identity factor. Actually, today the azulejo is regarded as one of the arts that best identifies Portuguese heritage. However, is it truly so? Is it reasonable to associate identity narratives with azulejo or is this idea connected only to issues of national marketing?Included in the Month of the Azulejo and the European Year of Cultural Heritage, AzLab#42 special seminar, entitled Identity(ies) of the azulejo in Portugal [1], aimed at debating issues of identity related to glazed tiles, focusing its attention both on the historiographic construction of this (these) concept(s) and on the different points that distinguish the Portuguese usage of the glazed tile from how other countries understand this art form.Following a protocol signed between the Rede de Investigação em Azulejo (Azulejo Research Network – ARTIS-IHA/FLUL) and the Amigos do Museu Nacional do Azulejo Association (Friends of the National Azulejo Museum), AzLab#42 took place at Amphitheater III of the School of Arts and Humanities of the University of Lisbon on October 4, 2018. The international call for papers had a significant number of proposals, from which, after a blind peer-review process, six were selected. To the latter, three other sessions were added with guest-speakers whose work has been acknowledged in this field of study, which in turn led to vigorous discussions in the several debates held during the seminar.For the reasons given, because it secures contributes of the several authors with different educational backgrounds and nationalities, the conference proceedings now published are enormously relevant for the future. In addition, this volume also fulfills one of the initial goals of this initiative: to introduce the scientific community’s perspective of this matter and contribute to the theoretical support of the Portuguese azulejo’s application to UNESCO World Heritage.ARTis ON’s special number mirrors AzLab#42 seminar’s program. As a result, it starts with a set of articles related to historiography, featuring studies dedicated to general themes which are followed by more specific ones. Nuno Rosmaninho’s article opens this volume with a study entitled “Portuguese azulejos and other national arts” in which the author seeks to “link the identity appropriation of the azulejo to a source common to most artistic discourse in the nineteenth and twenty-first centuries”.Focusing on differentiating issues, Alexandra Gago da Câmara and Rosário Salema de Carvalho list originality facts identified by European historiography until the mid-twentieth century, observing how these spring from seemingly diverse ideas to actually embody a set of well-defined points. From an even more funnelled perspective, Sandra Leandro explores Joaquim de Vasconcelos’ role in this context while João Pedro Monteiro addresses one of the most significant researchers in the glazed tile field of study – João Miguel dos Santos Simões.The appreciation of the convergent and divergent points between Portuguese and Spanish tiles, understood as focal loci for the azulejo’s universal reach, is presented by Jaume Coll Conesa. Following this study, there is a set of articles that, addressing the call for papers’ theme “azulejo: what identity(ies)”, considers certain distinctive characteristics. Fátima Rodrigues and Pedro J. Freitas analyse patterned tiles using mathematical models of classification; Cristina Carvalho examines advertising panels; Shelley Miller shows how her artistic interventions call the concept of identity into question and, continuing with contemporaneous studies, Inês Leitão ends this section by analysing how artists perceive identity issues associated with the azulejo.However, there is still plenty to debate and clarify. Indeed, one of the most interesting points concerning AzLab#42, and the articles now published, rests on the range of topics that arise as future research perspectives. Nevertheless, is the importance acknowledged to the azulejo today, how it distinguishes national landscape – whether by its physical presence or as a key element in the Portuguese collective imaginary – as well as its role as a reference to a broad set of other cultural and artistic displays, ranging from fashion to cuisine, enough to grant it the status of a culture’s identity defining art form? Or are we sometimes witnessing a discourse that aims to subordinate Portuguese tiles to a wider narrative, making them fit into a set of supposedly distinctive factors, which actually intends to build a national image for foreign consumption?Since we believe this volume is a contribution to the future and that from this initiative several others might be held, for the moment we must thank all participants and AzLab#42’s Scientific and Executive Committee. In addition, we would like to highlight the support given by Inês Leitão in terms of graphic design and organisation as well as by Rafaela Xavier and Fábio Ricardo.---[1] AzLab is a monthly seminar organised by the Az group – Azulejo Research Network, of ARTIS – Instituto de História da Arte da Faculdade de Letras da Universidade de Lisboa (Art History Institute of the School of Arts and Humanities of the University of Lisbon), in collaboration with the National Azulejo Museum (https://blogazlab.wordpress.com). AzLab’s goal is to create new analysis perspectives on issues related to the azulejo, among which are research, inventory, collecting, safeguarding, creating or divulging. The idea of developing a research lab on azulejo, which addresses experimental procedure concepts associated with these spaces, is applied to the discussion AzLab wishes to promote. It also introduces a concept foreign to art history, aiming at developing a multidisciplinary research. Every month a theme is submitted to public debate, which may stem from research projects, masters’ dissertations, PhD thesis, among others. National researchers, who are connected to the most diverse institutions, are invited to participate as well as, whenever possible, foreign scholars. AzLab#42 special Identity(ies) of the Azulejo in Portugal was a one-day conference, which was co-organised by the Amigos do Museu Nacional do Azulejo Association and also supported by Centro Atlântico publisher.

Performance of Rutile as an Antibacterial Material in Ceramic Tiles

The study was focused on the performance of rutile addition in the glaze for antibacterial application. Rutile powder in micro size (<5µm) (at different composition 5 wt%, 7 wt%, 9 wt%, 10 wt% and 15 wt%) were added in the glaze. Glazing was performed by dipping method for 10 seconds. Glazed tile was then sintered at 1200°C for 1 hour. Characterizations used to observe the properties of produced tiles were physical observation, scanning electron microscopy (SEM) and X-ray diffraction (XRD). Optimum sample was undergone an antibacterial test towards E.coli.