Enhanced IR Radiative Cooling of Silver Coated PA Textile

Smart textile with IR radiative cooling is of paramount importance for reducing energy consumption and improving the thermal comfort of individuals. However, wearable textile via facile methods for indoor/outdoor thermal management is still challenging. Here we present a novel simple, yet effective method for versatile thermal management via silver-coated polyamide (PA) textile. Infrared transmittance of coated fabric is greatly enhanced by 150% due to the multi-order reflection of silver coating. Based on their IR radiative cooling, indoors and outdoors, the skin surface temperature is lower by 1.1 and 0.9 °C than normal PA cloth, allowing the textile to be used in multiple environments. Moreover, the coated fabric is capable of active warming up under low voltage, which can be used in low-temperature conditions. These promising results exemplify the practicability of using silver-coated textile as a personal thermal management cloth in versatile environments.

Preparation and Preliminary Evaluation of Silver-Modified Anodic Alumina for Biomedical Applications

The present study reports a specific method for preparation of silver-modified anodic alumina substrates intended for biomaterial applications. Al2O3 coatings were obtained by anodization of technically pure aluminum alloy in sulfuric acid electrolyte. Silver deposition into the pores of the anodic structures was carried out employing in situ thermal reduction for different time periods. The obtained coatings were characterized using scanning electron microscopy (SEM), potentiodynamic scanning after 168 h in 3.5% NaCl solution and bioassays with human fibroblast and NIH/3T3 cell lines. The modified alumina substrates demonstrated better biocompatibility compared to the control anodic Al2O3 pads indicated by increased percent cell survival following in vitro culture with human and mouse fibroblasts. The Ag-deposition time did not affect considerably the biocompatibility of the investigated anodic layers. SEM analyses indicated that mouse NIH/3T3 cells and human fibroblasts adhere to the silver-coated alumina substrates retaining normal morphology and ability to form cell monolayer. Therefore, the present studies demonstrate that silver coating of anodic alumina substrates improves their biocompatibility and their eventual biomedical application.

Analyte-restrained silver coating of gold nanostructures: An efficient strategy to advance multicolorimetric probes

Visual detection based on gold nanorods (AuNRs) has gained tremendous attention in sensing applications owing to the potential for simple, inexpensive, instrument-free, and on-site detection. The proper selection of the mechanism involved in the interaction between the analyte and the nanostructure plays a significant role in designing a selective and multicolorimetric probe for visual purposes. A winning mechanism to develop multicolorimetric probes is the silver metalization of AuNRs. Herein, an unprecedented idea is presented to expand the variety of multicolorimetric sensors relying on the mechanism of silver deposition. We introduce the anti-silver deposition mechanism in which the analyte directly or indirectly restrains the silver coating of AuNRs. To ascertain the anti-silver deposition mechanism, we have exploited the proposed idea for the direct detection of nitrate. The presence of nitrate (as restrainer agent), which was firstly treated with ascorbic acid (as reducing agent), induced a decrease in the spectral blueshift of AuNRs along with diverse sharp color transitions from reddish-orange (blank) to maroon, wine, berry/purple, dark blue, teal, green, seafoam, and mint. The difference in the surface area of the probe’s spectra in the absent (Sₒ) and presence (S) of nitrate were linearly proportional to nitrate concentration in the range of 0.5 to 5.5 mmol L-1 and the limit of detection (LOD) was calculated to be 465 µmol L-1. Furthermore, the practicability of the multicolor probe was assessed by the determination of nitrate in complex environmental samples.

Combining thermal insulation and mobile communication in buildings: influence of laser-treated glazing on microwave propagation

With the purpose of reducing the heating energy in buildings, it is common practice to install energy-efficient windows to increase the thermal insulation of a façade. These insulating glass units (IGIJ) include a thin silver coating acting as an infrared mirror which reduces the thermal losses that occur through radiation, but at the same time reflects the microwaves for mobile communication. To address this drawback, a specific laser treatment is performed on the silver coating which strongly improves the transmission of microwaves through the window. In this study, the attenuation of microwaves signal was analyzed inside the SolAce unit in the "NEST" research building at the Swiss Federal Laboratories for Materials Science and Technology (EMPA) in Dübendorf. Two configurations (with and without laser-treated glazing) were carried out by interchanging two hinged windows. The results showed a significant improvement in signal strength in the configuration with laser-treated IGUs. A transmission loss contour plot of the SolAce unit showed a highly directional propagation of the wave which suggests that more than two windows should be treated to achieve better mobile communication in the entire unit. The novel patterned coating is thus especially valuable in the building sector to increase the microwave signal for mobile communication. To the best of our knowledge, this is the first implementation and testing of laser-treated coating for energy-efficient glazing in the building sector.

Deposition of Super-Hydrophobic Silver Film on Copper Substrate and Evaluation of Its Corrosion Properties

A simple and versatile chemical solution deposition process is reported to manipulate the wettability properties of copper sheets. The whole process has the advantage of being time-saving low cost and environment-friendly. An adherent silver coating was achieved under optimal conditions. Scanning electron microscopy and X-ray diffraction were used to examine the silver film structure. A confocal microscope was used to record the 3D topography and assess the film roughness of the surface. A dual morphology was revealed, consisting of broad regions with feather-like structured morphologies and some areas with spherical morphologies. Such silver-coated copper samples exhibited a sufficiently stable coating with superhydrophobicity, having a maximum water contact angle of 152°, along with an oleophilic nature. The corrosion behavior of the produced hydrophobic copper under optimal conditions was evaluated by means of potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) using a 3.5% NaCl solution. The corrosion protection mechanism was elucidated by the proposed equivalent circuits, indicating that the superhydrophobic silver coating acted as an effective barrier, separating the Cu substrate from the corrosive solution. The superhydrophobic coating demonstrated enhanced anti-corrosion properties against NaCl aqueous solution in relation to the copper substrate as indicated from both EIS and potentiodynamic polarization experiments.

Preparation of silver coated oxide nanomaterials and study of their properties

Annotation. Nanopowders of aluminum oxide silicon oxide and iron oxide with silver coating were produces by the radiation-chemical method. The dimensions of the nanoparticles were 50 to 80 nm, and the area can be changed from 2-3%, up to 40%. Was carried out the validation of antibacterial properties against E.coli and staphylococcus. Were estimated photocatalytic properties of nanopowders, which showed applications perspective as a photocatalytic agent. Cytotoxic properties were also investigated, which showed the relevance of the use of some the obtained composites for targeted drug delivery.

Effect of high-temperature oxidation on the surface properties as applied to quenching of high-temperature bodies

This paper contains the results of studying the surface properties before and after high-temperature oxidation. For this, the plate zirconium samples with chromium, gold and silver coatings were prepared. Cut profiles of the samples were obtained to study the structure of coatings and the thickness of the oxide layer. The measurements of contact angles were carried out. The results showed that a porous heterogeneous oxide layer was formed on the samples after high-temperature oxidation. At the same time, the wettability of the samples was improved. The thickness of the oxide layer on the chrome-coated zirconium sample was the smallest. Using of electroplated silver coating for experiments involving heating to high temperatures seems inappropriate because it was damaged after the oxidation tests. It is assumed that the main factor which influence on the rise of the transition temperature to the intensive cooling regime during quenching is the appearance of the oxide layer, rather than the improved wettability and wickability. High-temperature oxidation leads to the simultaneous formation of an oxide layer with a low thermal effusivity and to an improvement in wettability, therefore the contribution of each of these two effects on quenching can be confused or overestimated.