Ioannis (Yiannis) Karapanagiotis

Aristotle University of Thessaloniki | AUTH · Department of Chemistry

Silane-based materials are used for the protection of heritage and modern buildings. A versatile method is developed to tune the wetting properties of a typical silane-based material from hydrophobicity to superamphiphobicity, thus enhancing the protective efficacy against rainwater and organic pollutants. A commercially available silane product is...

Non-wettable surfaces have been uninterruptedly studied during the 20th century [...]

Astronauts are spending longer periods locked up in ships or stations for scientific and exploration spatial missions. The International Space Station (ISS) has been inhabited continuously for more than 20 years and the duration of space stays by crews could lengthen with the objectives of human presence on the moon and Mars. If the environment of...

In the last two decades superhydrophobic (contact angle of water drop, WCA > 150°) and superamphiphobic (WCA > 150° & contact angle of oil drop, OCA > 150°) materials have attracted considerable attention due to their numerous applications. These non-wettable materials have the potential to open new avenues for the protection, conservation and pres...

The goal of the study was to characterize the limestone that was used extensively in the ancient city of Pella (Macedonia, Greece), the birthplace of Alexander the Great. An on-site examination of the building material was carried out to record the types of damage and to select sampling areas. A variation in the nature of the stone and the degree o...

High Performance Liquid Chromatography coupled to a Diode-Array-Detector (HPLC-DAD) is used to investigate samples which were extracted from ancient Egyptian textiles (4th–5th c. AD) of the Museum of Faculty of Archaeology, Cairo University. Madder is identified in several samples. According to semi-quantitative results, which are obtained from HPL...

The preservation of cultural heritage monuments and artifacts requires the development of methods to produce water-repellent materials, which can offer protection against the effects of atmospheric water. Fluorosilanes are a very promising class of materials, as they act as precursors for the formation of low surface energy polymer networks. 1H,1H,...

A decorated and carved wooden door of the late Byzantine period (14th Century), which belongs to the Dionysiou Monastery in Mount Athos, Greece, constitutes an important relic of valuable technological information due to its construction technology and history. Seventeen (17) samples detached from the door are studied using optical microscopy, scan...

A HPLC method coupled with diode array detector was developed and validated for the quantitation of alizarin, apigenin, carminic acid, curcumin, ellagic acid, emodin, fisetin, kaempferide, kaempferol, kermesic acid, morin, purpurin, quercetin and sulfuretin which are components of several natural dyes. 1- Hydroxyanthraquinone was selected as intern...

Superhydrophobicity and self-cleaning induced by photocatalysis have tremendous potential for numerous applications. The fundamental concepts of these two phenomena are described, and some crucial aspects, related to the wettability of solid surfaces, are stressed. Previously published reports describing the use of superhydrophobic and photocatalyt...

Tetraethyl orthosilicate (TEOS) is extensively used in the conservation of stone-built cultural heritage, which is often subjected to water-induced degradation processes. The goal of this study was to produce and study a TEOS-based material with the ability to repel liquid water. A sol solution of TEOS and 1H,1H,2H,2H-perfluorooctyl triethoxysilane...

The production and use of the pigment extracted from the murex molluscs is discussed here in association with the purple textile dyeing industry in the Prehistoric Aegean. “True” purple has been identified in a number of archaeological finds dating from the early Late Bronze Age, found in old and recent excavations at three different but contempora...

This chapter provides a brief review of methods devised to impart superhydrophobicity to textiles using nanoparticles, combined usually with other materials, as hydrophobing agents. Nanoparticles have opened new avenues for the production of multifunctional textiles and therefore in some of the reviewed methods, superhydrophobic textiles show simul...

This book aims at identifying novel advanced materials of extreme wetting properties (MEWP) for practical, industrial applications. The state-of-the art superhdyrophobic, superhdyrophilic, superoleophobic, superoleophilic, and superomniphobic materials, that are MEWP, with respect to their technological and emerging industrial applications are disc...

In the last two decades, materials of extreme wetting properties have received significant attention, as they offer new perspectives providing numerous potential applications [...]

Decohesion of building materials caused by weathering translates into the need for recurrent interventions with consolidating treatments that often turn out useless for desired long-term consolidation owing to their poor in-depth penetration. Due to this, it is important to develop new products that allow evaluating their penetration in situ. In th...

Calcium hydroxide (Ca(OH2)) nanoparticles are produced following an easy, ion exchange process. The produced nanoparticles are characterized using transmission electron microscopy (TEM) and Fourier- transform infrared spectroscopy (FTIR) and are then dispersed in an aqueous emulsion of silanes/siloxanes. The dispersions are sprayed on marble and th...

Waterborne polysiloxane coatings can obtain superhydrophobic and water-repellent properties by embedding oxide nanoparticles into the organosilicon matrix during coating deposition. The nanoparticles induce surface roughness resulting to extreme wetting properties. This general strategy is demonstrated and implemented in this case study where a com...

The efficacy of poly(vinyl alcohol) and borax (PVA-b) films to remove varnishes of natural resins from paint samples is studied. Samples prepared according to the egg tempera technique were varnished with mastic, dammar (triterpenoid resins), sandarac, copal, colophony (diterpenoid resins), and shellac and were subjected to artificially accelerated...

Paraloid B72 is a very important product in the conservation and restoration science and practice, particularly for cultural heritage and artistic objects. It is an inherent hydrophilic copolymer of methyl acrylate and ethyl methacrylate. In this study, superhydrophobicity is induced in Paraloid coatings by embedding silica (SiO2) nanoparticles int...

Shellfish purple, also known as Tyrian purple and royal purple, has a long history, which has been revealed and documented in recent years through valid physicochemical studies using sophisticated techniques. The aim of the work was to summarize the conclusions of these studies and to describe the results of two unpublished investigations regarding...

High-performance liquid chromatography coupled to a diode-array detector (HPLC-DAD) is used to investigate 30 samples which were removed from 27 ancient Egyptian fabrics of the Fill-Trevisiol collection. Attention is focused in this paper on fabrics of the Roman and Byzantine periods, with red and deep violet–blue wool weft threads which are Z-spun...

This study conducted a comparison between biocide treatments based on nanoparticles of silver, copper, ZnO, TiO2 and silver/ TiO2 nanocomposites to analyse their capability to inhibit microalgal fouling on stone buildings. Biofouling is one of the main alterations on stone façades, causes degradation of their constituent materials and interferes wi...

In the last two decades materials of extreme wetting properties (MEWP) have received significant attention, as they offer new perspectives providing numerous potential applications. Biomimetics, super-hydrophobic/oleophobic and water/oil-repellent surfaces can be used, for instance, in automobiles, ships and aircrafts, microelectronics, textiles, b...

The effects of harsh UV radiation (λ = 254 nm) on wool and silk dyed with Hexaplex (Murex) trunculus extract are investigated using HPLC-DAD, colourimetry, SEM and FTIR. Indigotin, 6-bromoindigotin, 6,6′-dibromoindigotin and 6,6′-dibromoindirubin were quantified by an efficient HPLC-DAD method which was validated in terms of linearity, detection an...

The aim of this study is the characterization of a portable icon of Virgin Mary “Eleousa”, from the village of Kleidi, Northern Greece. The icon is dated in the second half of 19th century, and its stylistic features typify it as a representative example of post-Byzantine folk ecclesiastical art of Northern Greece. Micro-samples of the painting and...

Saint Demetrius of Stomion is a historical monastery placed in the geographical area of Larissa town, Greece, with a remarkable presence from its founding until nowadays. The monastery's present catholicon (main church) has been dated in the 16th century and its surviving wall paintings were constructed in 1758. In addition to the characterization...

The major finding from this work is the HPLC identification of shellfish purple in a textile fragment which was found in a sarcophagus dated to the late 3rd or early 4th century in the city of Thessaloniki (Greece).

Representing St. Athanasios of Alexandria, and found buried a century ago in Northern Greece, the portable icon under study displays a rare substrate; its panel is a unique example of a wooden instrument in secondhand use. In particular, a threshing board, a common in the Mediterranean basin agricultural instrument, was used as the panel of the ico...

This work describes a holistic archaeometric approach to ancient Macedonian specimens. In the region of the ancient city Lete, the deceased members of a rich and important family were interred in a cluster of seven tombs (4th century BC). Among the numerous grave goods, there was also a set of metal containers preserving their original content. The...

The cross-section stratifications of samples, which were removed from six icons, are studied using optical microscopy, micro-Raman spectroscopy, and micro-Fourier transform infrared (FT-IR) spectroscopy. The icons, dated from the 14th to 19th centuries, are prominent examples of Byzantine painting art and are attributed to different artistic worksh...

Silica nanoparticles were dispersed in an aqueous emulsion of alkoxy silanes and organic fluoropolymer. The dispersion was sprayed onto white marble and sandstone. The deposited composite coatings exhibited (i) superhydrophobicity and superoleophobicity, as evidenced by the high (>150°) static contact angles of water and oil drops as well as (ii) w...

This study explores the authentication of a bronze statue by means of the evaluation of technical evidence and investigation of patinas formation. The statue was identified by the police as a product of illicit excavation and handed to the Archaeological Museum of Thessaloniki. The visual examination reveals technical features that are consistent w...

A method to produce multifunctional coatings for the protection of silk is developed. Aqueous dispersion, free of any organic solvent, containing alkoxy silanes, organic fluoropolymer, silane quaternary ammonium salt, and silica nanoparticles (7 nm in mean diameter) is sprayed onto silk which obtains (i) superhydrophobic and superoleophobic propert...

Superhydrophobic and water repellent coatings can have numerous applications including the protection of monuments and other stone objects of the cultural heritage. In this study, the fundamental observations, concepts, and equations provided by T. Young, R.N. Wenzel, A.B.D. Cassie, S. Baxter, and other researchers on the wettability of solid surfa...

This book identifies novel advanced materials that can be utilized as protective agents for the preservation of stone. The innovative solutions to stone conservation presented here result in increased sustainability, reduced environmental impact, and increased social and economic benefits. It provides an overview of recent trends and progress in ad...

The goal of the study is the identification of pigments and other materials contained in wall paintings of three Macedonian tombs which date back to the fourth to third century BC: the tomb I of Dion, the tomb IV of Dion, and the tomb A (Heuzey). The investigation is carried out in two phases. First, portable X-ray fluorescence (XRF) spectroscopy i...

Moisture presence, salt precipitation and crystallization, temperature and ultraviolet radiation are main environmental factors of deterioration of the building materials of historic monuments. The presence of moisture in a material is due to rising and falling damp. Many commercial stone consolidation and water-repellent products contain tetraetho...

Quantitative HPLC and colorimetry are used to study color variations in dyeings with indigo, 6-bromoindigo, and 6,6′-dibromoindigo, the main components of the historic dye Tyrian purple. For the first time, visible light is identified conclusively as a cause of debromination of the leuco form of 6-bromoindigo. A dyeing run using 6-bromoindigo alone...

Samples removed from stucco ornaments of two mosques (seventeenth century) in El-Mahalla El-Kubra, Delta, Egypt, are investigated using optical microscopy, micro-Raman and micro-FTIR spectroscopy and X-ray diffraction (XRD). Samples are studied as removed from the ornaments and after treatment with trichloromethane, which was used to extract the or...

Polysiloxane materials have been used in conservation and protection of stone monuments and other outdoor objects of the cultural heritage for decades. Enhancing the inherent hydrophobic character of the siloxane materials is highly desirable as it can promote their protection efficacy against the degradation effects which are induced by rain water...

In this work we provide results of three analytical methods, e.g. micro-RAMAN, micro-FTIR and SEM/EDS, which were applied for the identification of pigments in 19th century icons for preservation and restoration purposes. These icons are stored in the Saint George church at the Asvestochori village near Thessaloniki, N. Greece. The two icons depict...

The fabrication of protective coatings on silk with special properties is presented. A water soluble siloxane emulsion enriched with silica nanoparticles (7 nm) is sprayed on silk, without the use of any organic solvent. By adjusting the nanoparticle concentration, treated silk obtains (i) superhydrophobic and superoleophobic properties, as evidenc...

A water soluble siloxane emulsion enriched with silica nanoparticles (7 nm) is sprayed on white marble and sandstone without the use of any organic solvent. A continuous rough structure, composed of numerous micro/nano structures, is formed at low nanoparticle concentration. Drops of water, glycerol, ethylene glycol and oil on coatings, which were...

A tuneable green process of textile cleaning is being optimized. The cleaning is achieved with supercritical carbon dioxide and an aqueous suspension as co-solvent. We managed to lower the operational pressure and examine the effect of the Ca(OH)2 concentration on the cleaning result. Soil and colour migration, particle size distribution and their...

The main churches of three monasteries in Thessalia, Central Greece were decorated with wall paintings in the post-Byzantine period. The main goal of the present study is to characterize the inorganic and organic materials present in the paint layers of areas that have been gilded. Optical microscopic examination was carried out on samples taken fr...

The wetting properties of the surfaces of polymer films changed dramatically from the usual inherent hydrophobicity (or slight hydrophilicity) to superhydrophobicity (contact angle, CA > 150°) by embedding oxide nanoparticles into the polymer matrices. The desired hierarchical roughness at the micrometer and nanometer scale was induced in poly(meth...

Indigotin, indirubin, 6-bromoindigotin, 6'-bromoindirubin, 6-bromoindirubin, 6,6'-dibromoindigotin and 6,6'-dibromoindirubin, the colouring components of Tyrian purple, are quantified by an efficient HPLC method coupled to a diode array detector. The compounds were separated using gradient elution, on a RP-column (Alltima C18, 250mm×3.0mm i.d., 5μm...

Samples from ecclesiastical textiles (epitaphioi) which date in the byzantine period (14th century) and belong to monasteries of Mount Athos, are investigated using High Performance Liquid Chromatography coupled to a Photodiode Array Detector (HPLC-PDA). Prior to HPLC analysis, the historic samples are treated following a two step method, which was...

The evaporation of water drops on sticky superhydrophobic poly(alkyl siloxane) surfaces, which were roughened by adding silica nanoparticles (7 nm) is monitored. Drop evaporation on surfaces corresponding to a high nanoparticle/polymer mass ratio (>0.1) is dominated by the constant contact radius (CCR) mode, with unchanged contact area between the...

Samples removed from funeral figurines, dated the third to the second century BC (Hellenistic period) and found in Macedonia, Greece, are investigated using high-performance liquid chromatography. Two results are reported that provide new insights into ancient polychromy. Firstly, high-performance liquid chromatography results, in combination with...

Fourier transform infrared spectroscopy and imaging coupled to optical microscopy, scanning electron microscopy coupled to energy dispersive x-ray spectroscopy and high-performance liquid chromatography (HPLC) coupled to diode-array detection are used to investigate two samples removed from a painted decoration of a burial kline and a textile fragm...

Microsamples removed from funeral figurines, which were found in two Hellenistic (third to second centuries bc) and two Roman (first to second centuries ac) tombs in the centre of Thessaloniki, Greece, are investigated following a multi-analytical approach. Polarized light microscopy (PLM), X-ray fluorescence (XRF) spectroscopy, micro-Raman spectro...

Silica nanoparticles (7 nm) were dispersed in solutions of a silane/siloxane mixture. The dispersions were applied, by brush, on four types of paper: (i) modern, unprinted (blank) paper, (ii) modern paper where a text was printed using a common laser jet printer, (ii) a handmade paper sheet detached from an old book (early 20th century) and (iv) Ja...

The goal of the study is to compare the dyes used in ecclesiastical post-Byzantine (sixteenth to early twentieth century) textiles of Mount Athos, Greece, with the corresponding organic colourants used in Ottoman (sixteenth to eighteenth century) textiles which are preserved in the Topkapi Palace Museum, Turkey. During the historical period of inte...

According to the World Heritage Committee, Mount Athos is considered to be of an outstanding universal value, as it is the most important monastic centre of the Christian Orthodox Church. This research focuses on the findings from three (3) Byzantine liturgical textiles known as epitaphioi, which from a historical point of view are the most importa...

Purple was used in abundance to decorate the impressive Korou tomb, which was excavated in the necropolis area of Daskyleon and dated in the second half of the 6th c. BC. A multi-analytical study was carried out to investigate in detail two purple samples which were removed from (i) a painted/pigmented area of the tomb and (ii) a textile, found wit...

The cross-influence effects of treatment temperature and time on the wettability of a siloxane elastomer is investigated in detail, through static and tilt contact angle measurements. The material is heated at 400, 500, 600, 650, 700 and 800oC for various periods, ranging from 1 to 300 s. The siloxane surface is subjected to multiple wettability tr...

Purple was used in abundance to decorate the impressive Korou tomb, which was excavated in the necropolis area of Daskyleon and dated in the second half of the 6th c. BC. A multi-analytical study was carried out to investigate in detail two purple samples which were removed from (i) a painted/pigmented area of the tomb and (ii) a textile, found wit...

Organically modified silica (ORMOSIL) gels were produced through a sol-gel method and used to coat different materials, including glass, silicon, iron, paper and several stones, so as to examine potential applications ranging from coatings of biomedical devices to cultural monuments. Superhydrophobicity and water repellence were induced on the surf...

The extractions of indigo (Indigofera tinctoria L.) and safflower (Carthamus tinctorius L.) red and yellow from wool fibres are investigated using high performance liquid chromatography with photo-diode-array detection (HPLC–PDA) which is frequently coupled to Mass Spectrometry (HPLC–PDA–MS) for identification purposes. The efficiencies of dimethyl...

For the first time, indirubin, 6-bromoindirubin and 6′-bromoindirubin are detected in hypobranchial glands, removed from Murex brandaris molluscs. Liquid chromatography coupled to a diode array detector is used to analyse dimethyl sulfoxide extracts of brandaris molluscs, which were collected from the coastline of Thera island, Greece. The three af...

The effects of nanoparticles, embedded into the matrices of polymer films, on the wettabilities of the surfaces of the composite films are investigated following a two-fold procedure. First, five particles such as silica (of two sizes), tin oxide, alumina and zinc oxide ranged from 7 to 100 nm are mixed with a poly(methyl siloxane). Second, silica...

Silica nanoparticles are dispersed in aqueous solutions of silanes and siloxanes. The dispersions are deposited, by brush, on various materials which have been used in objects of the cultural heritage such as marble, sandstone, mortar, wood, cotton and ceramic. The effect of the particle concentration on the wettability of the surfaces of the compo...

The stratigraphies of twenty five (25) samples removed from twenty (20) icons of the Cretan School of iconography are studied using Optical Microscopy and micro-Raman spectroscopy. The objects are dated in 15th–17th c. and belong to the collection of the Benaki Museum, Athens, Greece. Cinnabar, red ochre, minium, yellow ochre, azurite, malachite, l...

Water is the main deterioration factor of monuments and outdoor objects of the cultural heritage. The application of (super)hydrophobic siloxane coatings constitutes a promising method for monument protection and consolidation. In this study, the polymerization process, occurred because of the air humidity, of siloxane based (super)hydrophobic coat...

Η ανακοίνωση εστιάζει στην τεχνική μελέτη που αφορά στα λειτουργικά επισκοπικά ενδύματα του Αγίου Διονυσίου, Επισκόπου Αιγίνης και Πολιούχου της Ζακύνθου που χρονολογούνται στον 16ο αι. Πρόκειται για δύο επιτραχήλια που λατρεύονται ως ιερά λείψανα και εκτίθενται στον Ναό του Αγίου Νικολάου στον Μώλο. Η εκκλησιαστική παράδοση αναφέρει ότι με αυτά ασ...

Superhydrophobicity - also known as water repellency - has recently attracted considerable attention because of its numerous potential applications. However, the fundamental concepts and equations describing the wettability of superhydrophobic surfaces have been known since the 1940s. These concepts are reviewed and discussed in the present feature...