scholarly journals Zinc Oxide for Functional Textile Coatings: Recent Advances

Coatings ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 550 ◽  
Author(s):  
Anja Verbič ◽  
Marija Gorjanc ◽  
Barbara Simončič
Keyword(s):  
Electrical Conductivity ◽  
Antimicrobial Activity ◽  
Particle Size ◽  
Zinc Oxide ◽  
Recent Progress ◽  
Future Directions ◽  
Moisture Management ◽  
Textile Functionalization ◽  
Particle Size And Shape ◽  
Multifunctional Properties

The use of ZnO for the functionalization of textile substrates is growing rapidly, since it can provide unique multifunctional properties, such as photocatalytic self-cleaning, antimicrobial activity, UV protection, flame retardancy, thermal insulation and moisture management, hydrophobicity, and electrical conductivity. This paper aims to review the recent progress in the fabrication of ZnO-functionalized textiles, with an emphasis on understanding the specificity and mechanisms of ZnO action that impart individual properties to the textile fibers. The most common synthesis and application processes of ZnO to textile substrates are summarized. The influence of ZnO concentration, particle size and shape on ZnO functionality is presented. The importance of doping and coupling procedures to enhance ZnO performance is highlighted. The need to use binding and seeding agents to increase the durability of ZnO coatings is expressed. In addition to functional properties, the cytotoxicity of ZnO coatings is also discussed. Future directions in the use of ZnO for textile functionalization are identified as well.

scholarly journals Effects of Ultrasound on Zinc Oxide/Vermiculite/Chlorhexidine Nanocomposite Preparation and Their Antibacterial Activity

Nanomaterials ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 1309 ◽  
Author(s):  
Karla Čech Barabaszová ◽  
Sylva Holešová ◽  
Kateřina Šulcová ◽  
Marianna Hundáková ◽  
Barbora Thomasová
Keyword(s):  
Antimicrobial Activity ◽  
Particle Size ◽  
Zinc Oxide ◽  
Antibacterial Activity ◽  
Ultrasonic Treatment ◽  
Nanocomposite Materials ◽  
Hybrid Nanocomposite ◽  
X Ray Diffraction ◽  
X Ray

Microbial infection and biofilm formation are both problems associated with medical implants and devices. In recent years, hybrid organic-inorganic nanocomposites based on clay minerals have attracted significant attention due to their application potential in the field of antimicrobial materials. Organic drug/metal oxide hybrids exhibit improved antimicrobial activity, and intercalating the above materials into the interlayer of clay endows a long-term and controlled-release behavior. Since antimicrobial activity is strongly related to the structure of the material, ultrasonic treatment appears to be a suitable method for the synthesis of these materials as it can well control particle size distribution and morphology. This study aims to prepare novel, structurally stable, and highly antimicrobial nanocomposites based on zinc oxide/vermiculite/chlorhexidine. The influence of ultrasonic treatment at different time intervals and under different intercalation conditions (ultrasonic action in a breaker or in a Roset’s vessel) on the structure, morphology, and particle size of prepared hybrid nanocomposite materials was evaluated by the following methods: scanning electron microscopy, X-ray diffraction, energy dispersive X-ray fluorescence spectroscopy, carbon phase analysis, Fourier transforms infrared spectroscopy, specific surface area measurement, particle size analysis, and Zeta potential analysis. Particle size analyses confirmed that the ultrasonic method contributes to the reduction of particle size, and to their homogenization/arrangement. Further, X-ray diffraction analysis confirmed that ultrasound intercalation in a beaker helps to more efficiently intercalate chlorhexidine dihydrochloride (CH) into the vermiculite interlayer space, while a Roset’s vessel contributed to the attachment of the CH molecules to the vermiculite surface. The antibacterial activity of hybrid nanocomposite materials was investigated on Gram negative (Escherichia coli, Pseudomonas aeruginosa) and Gram positive (Staphylococcus aureus, Enterococcus faecalis) bacterial strains by finding the minimum inhibitory concentration. All hybrid nanocomposite materials prepared by ultrasound methods showed high antimicrobial activity after 30 min, with a long-lasting effect and without being affected by the concentration of the antibacterial components zinc oxide (ZnO) and CH. The benefits of the samples prepared by ultrasonic methods are the rapid onset of an antimicrobial effect and its long-term duration.

The role of albumen (egg white) in controlled particle size and electrical conductivity behavior of zinc oxide nanoparticles

Vacuum ◽  
2011 ◽  
Vol 86 (2) ◽  
pp. 140-143 ◽  
Author(s):  
Prakash Thangaraj ◽  
Jayaprakash Rajan ◽  
Sathyaraj Durai ◽  
Sanjay Kumar ◽  
Ayalsomayajula RatnaPhani ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Particle Size ◽  
Zinc Oxide ◽  
Zinc Oxide Nanoparticles ◽  
Egg White ◽  
Oxide Nanoparticles ◽  
Electrical Conductivity Behavior ◽  
Conductivity Behavior

Dilatometer Studies of Pigment-Rubber Systems

1941 ◽  
Vol 14 (1) ◽  
pp. 113-124 ◽  
Author(s):  
H. C. Jones ◽  
H. A. Yiengst
Keyword(s):  
Particle Size ◽  
Zinc Oxide ◽  
Particle Surface ◽  
X Ray Diffraction ◽  
Vacuole Formation ◽  
X Ray ◽  
Rubber Compounds ◽  
Large Particles ◽  
Complete Study ◽  
Particle Size And Shape

Abstract A number of years ago Schippel observed that, when certain pigmented rubber stocks were stretched, there was a reduction in specific gravity of the compound. This he attributed to the separation of the rubber from the pigment, resulting in vacuole formation. Green confirmed Schippel's explanation with the aid of a microscope. He prepared photomicrographs of stretched rubber films showing the formation of vacuoles at coarse pigment particles and undispersed pigment acting as single large particles. These vacuoles were conical in shape, and extended from one or both sides of the particles in the direction of elongation. Depew and Easley reported microscopic results relating particle surface and particle size and shape to the formation of vacuoles in stretched rubber. Several years ago Holt and McPherson designed a dilatometer to measure the volume change of rubber compounds under tension. In stretching gum-rubber bands, they noted a decrease in volume, which they ascribed to the fibering of the rubber, and an increase in volume of pigmented rubber bands, which they explained by the formation of vacuoles around the pigment particles. Furthermore these investigators pointed out that the decrease in volume of rubber on stretching is influenced by the same considerations as the x-ray diffraction, since it is observed only above a certain critical elongation and is greater the higher the elongation, the lower the temperature, and the longer the time the sample is kept stretched. Holt and McPherson dealt almost entirely with gum stocks except that they included measurements on a whiting and a carbon black stock. The object of this investigation was to extend the work of Holt and McPherson to a more complete study of pigmented stocks, with particular reference to those compounded with zinc oxide.

scholarly journals Impact of Coseismic Frictional Melting on Particle Size, Shape Distribution and Chemistry of Experimentally-Generated Pseudotachylite

2020 ◽  
Vol 8 ◽  
Author(s):  
Leny Montheil ◽  
Virginia G. Toy ◽  
James M. Scott ◽  
Thomas M. Mitchell ◽  
David P. Dobson
Keyword(s):  
Particle Size ◽  
Host Rock ◽  
Fractal Dimensions ◽  
Rock Composition ◽  
Slip Rates ◽  
Shape Distribution ◽  
Frictional Behavior ◽  
Particle Size And Shape ◽  
Frictional Melting ◽  
Glass Compositions

In natural friction melts, or pseudotachylites, clast textures and glass compositions can influence the frictional behavior of faults hosting pseudotachylites, and are, in turn, sensitive to the processes involved in pseudotachylite formation. Quantification of these parameters in situations where the host rock composition and formation conditions are well-constrained, such as analogue experiments, may yield calibrations that can be employed in analysis of natural pseudotachylites. In this paper, we experimentally-generated pseudotachylites in granitoid rocks (tonalite and Westerly granite) at Pconf = 40 MPa and slip rates of ∼0.1 m s−1, comparable to the conditions under which natural pseudotachylite is known to form in Earth’s upper crust. We find variations in both clast textures and glass compositions that reflect formation processes, and probably influence the frictional behavior of similar natural faults hosting pseudotachylite. Quantification of particle size and shape distribution with a semi-automatic image analysis method, combined with analysis of glass and host-rock composition of these experimentally generated pseudotachylites, reveals that the textures of pseudotachylite material evolved by combinations of 1) comminution, 2) heterogeneous frictional flash melting, and 3) homogeneous (diffusive) clast melting and/or marginal decrepitation. Fractal dimensions of pseudotachylite-hosted clasts (D ∼ 3) that are greater than those of marginal fragmented host rock particles (gouge, D ∼ 2.4), reflect an increase of the intensity of comminution by slip localisation during a pre-melting phase. Chemical analyses demonstrate that these pseudotachylite glasses were generated by frictional flash melting, where host rock phases melt individually. Biotite is the least resistant to melting, feldspar intermediate, and quartz is the most resistant. The peudotachylite glass generated in these experiments has an alkaline composition, is depleted in SiO2 compared to the bulk host-rock, and shows heterogeneous compositions in a single sample related to proximity to host-rock minerals. The percentage contributions of host rock phases to the melt, calculated by a mixing model, shows that glass compositions are dominated by plagioclase and biotite. Within the melt, margins of clasts were dissolved uniformly by diffusion and/or affected by marginal decrepitation, resulting in convex and round shapes with convexities averaging ∼0.8 and circularities averaging ∼0.65.

Dual‐hormone artificial pancreas for management of type 1 diabetes: Recent progress and future directions

2021 ◽  
Author(s):  
Marco Infante ◽  
David A. Baidal ◽  
Michael R. Rickels ◽  
Andrea Fabbri ◽  
Jay S. Skyler ◽  
...  
Keyword(s):  
Type 1 Diabetes ◽  
Recent Progress ◽  
Artificial Pancreas ◽  
Future Directions

scholarly journals Photodegradation property and antimicrobial activity of zinc oxide nanorod-coated polypropylene nonwoven fabric

2021 ◽  
pp. 107235
Author(s):  
Guangyu Zhang ◽  
Ran Cheng ◽  
Jiawei Yan ◽  
Yao Xiao ◽  
Chuanfeng Zang ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Zinc Oxide ◽  
Nonwoven Fabric
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