scholarly journals Electrokinetic Characterization of Natural Stones Coated with Nanocomposites for the Protection of Cultural Heritage

2018 ◽  
Vol 8 (9) ◽  
pp. 1694 ◽  
Author(s):  
Marco Roveri ◽  
Simona Raneri ◽  
Sabrina Bianchi ◽  
Francesca Gherardi ◽  
Valter Castelvetro ◽  
...  
Keyword(s):  
Surface Modification ◽  
Water Absorption ◽  
Protective Coatings ◽  
Surface Wettability ◽  
Atmospheric Pollutants ◽  
Titania Nanoparticles ◽  
Streaming Current ◽  
Condensed Water ◽  
Natural Stones ◽  
Electrokinetic Characterization

Protective coatings, in recent years also from nanocomposite formulations, are commonly applied onto architectural stone and stone artefacts, mainly to prevent absorption of condensed water and dissolved atmospheric pollutants into the porous stone structure. While standard protocols to assess a coating’s performance are available, understanding the response of the coating-stone system is a complex task, due to the interplay of various factors determining the overall behaviour. Characterization techniques allowing one to correlate the extent and nature of surface modification upon treatment with the most relevant physical properties (i.e., water absorption and surface wettability) are thus of great interest. Electrokinetic analysis based on streaming current measurements, thanks to its sensitivity towards even minor changes in the surface chemical composition, may fulfil such requirement. Indeed, by involving the interaction with a testing aqueous electrolyte solution, this technique allows one to probe not only the outer surface, but also the outermost layer of the pore network, which plays a crucial role in the interaction of the stone with condensed atmospheric water. In this work, a correlation was found between the extent of surface modification, as determined by streaming current measurements, surface wettability and capillary water absorption, for three lithotypes with different mineralogical and microstructural properties treated with two nanocomposite formulations (one water based and one in alcoholic solvent) containing organosilica precursors and titania nanoparticles.

scholarly journals Electrokinetic Characterization of Natural Stones Coated with Nanocomposites for the Protection of Cultural Heritage

2018 ◽  
Author(s):  
Marco Roveri ◽  
Simona Raneri ◽  
Sabrina Bianchi ◽  
Francesca Gherardi ◽  
Valter Castelvetro ◽  
...  
Keyword(s):  
Surface Modification ◽  
Water Absorption ◽  
Protective Coatings ◽  
Surface Wettability ◽  
Atmospheric Pollutants ◽  
Streaming Current ◽  
Condensed Water ◽  
Natural Stones ◽  
Electrokinetic Characterization

Protective coatings, in recent years also from nanocomposite formulations, are commonly applied onto architectural stone and stone artefacts, mainly to prevent absorption into the porous stone structure of condensed water and dissolved atmospheric pollutants. While standard protocols are available to assess a coating’s performance, understanding the response of the coating-stone system is a complex task, due to the interplay of various factors determining the overall behaviour. Characterization techniques allowing to correlate the extent and nature of surface modification upon treatment with the most relevant physical properties (i.e water absorption and surface wettability) are thus of great interest. Electrokinetic analysis based on streaming current measurements, thanks to its sensitivity towards even minor changes in the surface chemical composition, may fulfil such requirement. Indeed, by involving the interaction with a testing aqueous electrolyte solution, this technique allows to probe not only the outer surface but also the outermost layer of the pore network, which plays a crucial role in the interaction of the stone with condensed atmospheric water. In this work a correlation was found between the extent of surface modification, as determined by streaming current measurements, surface wettability and capillary water absorption of 6 coating-lithotype combinations (3 lithotypes and 2 nanocomposites).

Electrokinetic Characterization of Nanocomposites Applied on Natural Stones by Streaming Current Measurements

2018 ◽  
Author(s):  
Marco Roveri ◽  
Simona Raneri ◽  
Sabrina Bianchi ◽  
Francesca Gherardi ◽  
Valter Castelvetro ◽  
...  
Keyword(s):  
Protective Coatings ◽  
Structural Complexity ◽  
Complex Task ◽  
Capillary Water ◽  
Stone Surface ◽  
Physical Behaviour ◽  
Streaming Current ◽  
Natural Stones ◽  
Electrokinetic Characterization

The characterization of protective coatings applied on natural stones is often a complex task due to the difficulty of identifying and quantifying the various factors contributing to the overall behaviour of the coating-stone system. In particular, linking information about the coating-stone interaction to macroscopic effects in terms of physical behaviour of treated stones can be especially arduous owing to the inherent structural complexity of stone substrates. Electrokinetic analysis based on streaming current measurements, having already proved the ability to sense even minor changes in the chemical composition of different materials surfaces upon treatment, may provide useful insights in view of better understanding the extent of stone surface modification. In particular, involving the interaction of stones with a water-based solution, the streaming current technique could extend the characterization of stone surface to the outermost part of the pore network, which is part of every treatment-induced modification of surface properties. In this work, the effectiveness of streaming current measurements as analytical tool for the characterization of coatings applied on natural stones is assessed by considering different lithotypes and coatings and trying to correlate the results of electrokinetic analysis with the physical behaviour of treated stones, with specific regard to wettability and capillary water absorption.

scholarly journals Water uptake of various electrospun nonwovens

2020 ◽  
Vol 6 (3) ◽  
pp. 155-158
Author(s):  
Katharina Wulf ◽  
Volkmar Senz ◽  
Thomas Eickner ◽  
Sabine Illner
Keyword(s):  
Contact Angle ◽  
Surface Modification ◽  
Water Absorption ◽  
Water Uptake ◽  
Biomedical Applications ◽  
High Surface ◽  
Volume Ratio ◽  
Polymer Composition ◽  
Water Wetting ◽  
Morphology Changes

AbstractIn recent years, nanofiber based materials have emerged as especially interesting for several biomedical applications, regarding their high surface to volume ratio. Due to the superficial nano- and microstructuring and the different wettability compared to nonstructured surfaces, the water absorption is an important parameter with respect to the degradation stability, thermomechanic properties and drug release properties, depending on the type of polymer [1]. In this investigation, the water absorption of different non- and plasma modified biostable nanofiber nonwovens based on polyurethane, polyester and polyamide were analysed and compared. Also, the water absorption by specified water wetting, the contact angle and morphology changes were examined. The results show that the water uptake is highly dependent on the surface modification and the polymer composition itself and can therefore be partially changed.

Effect of fiber surface modification on water absorption and hydrothermal aging behaviors of GF/pCBT composites

2015 ◽  
Vol 82 ◽  
pp. 84-91 ◽  
Author(s):  
Bin Yang ◽  
Jifeng Zhang ◽  
Limin Zhou ◽  
Mingkun Lu ◽  
Wenyan Liang ◽  
...  
Keyword(s):  
Surface Modification ◽  
Water Absorption ◽  
Fiber Surface ◽  
Hydrothermal Aging

Biocompatible Ceramic-Biopolymer Coatings Obtained by Electrophoretic Deposition on Electron Beam Structured Titanium Alloy Surfaces

2016 ◽  
Vol 879 ◽  
pp. 1552-1557
Author(s):  
C. Ramskogler ◽  
L. Cordero ◽  
Fernando Warchomicka ◽  
A.R. Boccaccini ◽  
Christof Sommitsch
Keyword(s):  
Titanium Alloy ◽  
Surface Modification ◽  
Electron Beam ◽  
Electrophoretic Deposition ◽  
Composite Coatings ◽  
Substrate Surface ◽  
3D Structure ◽  
Titania Nanoparticles ◽  
Structured Surfaces ◽  
Major Interest

An area of major interest in biomedical engineering is currently the development of improved materials for medical implants. Research efforts are being focused on the investigation of surface modification methods for metallic prostheses due to the fundamental bioinert character of these materials and the possible ion release from their surfaces, which could potentially induce the interfacial loosening of devices after implantation. Electron beam (EB) structuring is a novel technique to control the surface topography in metals. Electrophoretic deposition (EPD) offers the feasibility to deposit at room temperature a variety of materials on conductive substrates from colloidal suspensions under electric fields. In this work single layers of chitosan composite coatings containing titania nanoparticles (n-TiO2) were deposit by EPD on electron beam (EB) structured Ti6Al4V titanium alloy. Surface structures were designed following different criteria in order to develop specific topography on the Ti6Al4V substrate. n-TiO2 particles were used as a model particle in order to demonstrate the versatility of the proposed technique for achieving homogenous chitosan based coatings on structured surfaces. A linear relation between EPD time and deposition yield on different patterned Ti6Al4V surfaces was determined under constant voltage conditions, obtaining homogeneous EPD coatings which replicate the 3D structure (pattern) of the substrate surface. The present results show that a combination of both techniques can be considered a promising surface modification approach for metallic implants, which should lead to improved interaction between the implant surface and the biological environment for orthopaedic applications.

scholarly journals Effect of protective coatings on the water absorption and mechanical properties of 3D printed PLA

2019 ◽  
Vol 13 (48) ◽  
pp. 748-756 ◽  
Author(s):  
Carlos Vicente ◽  
João Fernandes ◽  
Augusto Deus ◽  
Maria Vaz ◽  
Marco Leite ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Water Absorption ◽  
Protective Coatings ◽  
3D Printed

scholarly journals Controlled Surface Wettability by Plasma Polymer Surface Modification

Surfaces ◽  
2019 ◽  
Vol 2 (2) ◽  
pp. 349-371 ◽  
Author(s):  
Muzammil Iqbal ◽  
Duy Khoe Dinh ◽  
Qasim Abbas ◽  
Muhammad Imran ◽  
Harse Sattar ◽  
...  
Keyword(s):  
Surface Modification ◽  
Surface Chemistry ◽  
Plasma Polymerization ◽  
Polymer Surface ◽  
Real Life ◽  
Polymer Coatings ◽  
Surface Wettability ◽  
Smart Polymer ◽  
Wetting Behavior ◽  
Polymer Surface Modification

Inspired by nature, tunable wettability has attracted a lot of attention in both academia and industry. Various methods of polymer surface tailoring have been studied to control the changes in wetting behavior. Polymers with a precisely controlled wetting behavior in a specific environment are blessed with a wealth of opportunities and potential applications exploitable in biomaterial engineering. Controlled wetting behavior can be obtained by combining surface chemistry and morphology. Plasma assisted polymer surface modification technique has played a significant part to control surface chemistry and morphology, thus improving the surface wetting properties of polymers in many applications. This review focuses on plasma polymerization and investigations regarding surface chemistry, surface wettability and coating kinetics, as well as coating stability. We begin with a brief overview of plasma polymerization; this includes growth mechanisms of plasma polymerization and influence of plasma parameters. Next, surface wettability and theoretical background structures and chemistry of superhydrophobic and superhydrophilic surfaces are discussed. In this review, a summary is made of recent work on tunable wettability by tailoring surface chemistry with physical appearance (i.e. substrate texture). The formation of smart polymer coatings, which adjust their surface wettability according to outside environment, including, pH, light, electric field and temperature, is also discussed. Finally, the applications of tunable wettability and pH responsiveness of polymer coatings in real life are addressed. This review should be of interest to plasma surface science communality particularly focused controlled wettability of smart polymer surfaces.

Surface Modification of Titania Nanoparticles Using Ultrathin Ceramic Films

2006 ◽  
Vol 89 (10) ◽  
pp. 3070-3075 ◽  
Author(s):  
Luis F. Hakim ◽  
Jarod A. McCormick ◽  
Guo-Dong Zhan ◽  
Alan W. Weimer ◽  
Peng Li ◽  
...  
Keyword(s):  
Surface Modification ◽  
Titania Nanoparticles ◽  
Ceramic Films
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