Surface Coating-Modulated Phytotoxic Responses of Silver Nanoparticles in Plants and Freshwater Green Algae

Silver nanoparticles (AgNPs) have been implemented in a wide range of commercial products, resulting in their unregulated release into aquatic as well as terrestrial systems. This raises concerns over their impending environmental effects. Once released into the environment, they are prone to various transformation processes that modify their reactivity. In order to increase AgNP stability, different stabilizing coatings are applied during their synthesis. However, coating agents determine particle size and shape and influence their solubility, reactivity, and overall stability as well as their behavior and transformations in the biological medium. In this review, we attempt to give an overview on how the employment of different stabilizing coatings can modulate AgNP-induced phytotoxicity with respect to growth, physiology, and gene and protein expression in terrestrial and aquatic plants and freshwater algae.

Past and Current Progress in the Development of Antiviral/Antimicrobial Polymer Coating towards COVID-19 Prevention: A Review

The astonishing outbreak of SARS-CoV-2 coronavirus, known as COVID-19, has attracted numerous research interests, particularly regarding fabricating antimicrobial surface coatings. This initiative is aimed at overcoming and minimizing viral and bacterial transmission to the human. When contaminated droplets from an infected individual land onto common surfaces, SARS-CoV-2 coronavirus is able to survive on various surfaces for up to 9 days. Thus, the possibility of virus transmission increases after touching or being in contact with contaminated surfaces. Herein, we aim to provide overviews of various types of antiviral and antimicrobial coating agents, such as antimicrobial polymer-based coating, metal-based coating, functional nanomaterial, and nanocomposite-based coating. The action mode for each type of antimicrobial agent against pathogens is elaborated. In addition, surface properties of the designed antiviral and antimicrobial polymer coating with their influencing factors are discussed in this review. This paper also exhibits several techniques on surface modification to improve surface properties. Various developed research on the development of antiviral/antimicrobial polymer coating to curb the COVID-19 pandemic are also presented in this review.

Granular fertilizer caking: A research on the performance evaluation of coating agents

Caking formation in fertilizer products during handling and storage is a frequently encountered problem. Caked fertilizers become together as lumps, lose their free- flowing properties, and create inefficient applications. Several parameters such as relative humidity and temperature of the environment, pressure by pile height, and physicochemical properties of fertilizer product such as moisture content, presence of fines and chemical composition, etc. cause or accelerate caking mechanism. Internal or external anticaking products have been proved to be effective in preventing the caking of fertilizer particles. Liquid or wax anticaking agents are applied externally as coatings on the fertilizer surface. This study focuses on the performance evaluation of commercially available liquid- wax anticaking agents coated on NP 20-20-0 fertilizer, classified as three main groups: petroleum-derived, alkyl amine-fatty acid containing mixtures and bio- based composition. Caking performance of coating products are evaluated via small-bag storage test in 4 sets, according to the results, petroleum derived and alkyl amine- fatty acid containing anticaking products show similar performance, whereas bio-based products’ performance is moderate. This study focuses on a practical approach that will help fertilizer industry about which type of coating product will be effective on the anticaking properties of nitrogenous fertilizers and gives brief results of the effect of commercially available products with various ranges of chemical composition on the caking process.

Assessment of Nanopollution in Water Environments from Commercial Products

The use of nano-enabled products (NEPs) can release engineered nanomaterials (ENMs) into water resources, and the increasing commercialisation of NEPs raises the environmental exposure potential. The current study investigated the release of ENMs and their characteristics from six commercial products (sunscreens, body creams, sanitiser, and socks) containing nTiO2, nAg, and nZnO. ENMs were released in aqueous media from all investigated NEPs and were associated with ions (Ag+ and Zn2+) and coating agents (Si and Al). NEPs generally released elongated (7–9 × 66–70 nm) and angular (21–80 × 25–79 nm) nTiO2, near-spherical (12–49 nm) and angular nAg (21–76 × 29–77 nm), and angular nZnO (32–36 × 32–40 nm). NEPs released varying ENMs’ total concentrations (ca 0.4–95%) of total Ti, Ag, Ag+, Zn, and Zn2+ relative to the initial amount of ENMs added in NEPs, influenced by the nature of the product and recipient water quality. The findings confirmed the use of the examined NEPs as sources of nanopollution in water resources, and the physicochemical properties of the nanopollutants were determined. Exposure assessment data from real-life sources are highly valuable for enriching the robust environmental risk assessment of nanotechnology.

Facile Fabrication of Polysaccharide Nanocomposites Using Ionic Gelation Method

Polysaccharide-based nanomaterials with significant biocompatibility and physiochemical features have been widely analyzed in modern biomedical nanotechnology. Chitosan-coating is an advantageous procedure to provide several pharmacological characteristics of chitosan on the reinforcement. Here, we fabricated polysaccharide nanocomposites using the facile ionic gelation method and sodium tripolyphosphate (TPP) cross-linker. The polysaccharide nanocomposites comprised natural cellulose and chitosan as reinforcement and coating agents, respectively. From the image of the scanning electron microscope, the nanocomposites indicated almost spherical dimensions with sizes below 60 nm. Results from X-ray powder diffraction and Fourier-transform infrared spectroscopy showed multifunctional properties of the nanocomposites related to both cellulose and chitosan. Therefore, the ionic gelation method is potentially appropriate to synthesize the polysaccharide nanocomposites for medically-related applications.

Coatings in Decellularized Vascular Scaffolds for the Establishment of a Functional Endothelium: A Scoping Review of Vascular Graft Refinement

Developments in tissue engineering techniques have allowed for the creation of biocompatible, non-immunogenic alternative vascular grafts through the decellularization of existing tissues. With an ever-growing number of patients requiring life-saving vascular bypass grafting surgeries, the production of functional small diameter decellularized vascular scaffolds has never been more important. However, current implementations of small diameter decellularized vascular grafts face numerous clinical challenges attributed to premature graft failure as a consequence of common failure mechanisms such as acute thrombogenesis and intimal hyperplasia resulting from insufficient endothelial coverage on the graft lumen. This review summarizes some of the surface modifying coating agents currently used to improve the re-endothelialization efficiency and endothelial cell persistence in decellularized vascular scaffolds that could be applied in producing a better patency small diameter vascular graft. A comprehensive search yielding 192 publications was conducted in the PubMed, Scopus, Web of Science, and Ovid electronic databases. Careful screening and removal of unrelated publications and duplicate entries resulted in a total of 16 publications, which were discussed in this review. Selected publications demonstrate that the utilization of surface coating agents can induce endothelial cell adhesion, migration, and proliferation therefore leads to increased re-endothelialization efficiency. Unfortunately, the large variance in methodologies complicates comparison of coating effects between studies. Thus far, coating decellularized tissue gave encouraging results. These developments in re-endothelialization could be incorporated in the fabrication of functional, off-the-shelf alternative small diameter vascular scaffolds.

Evaluation of Natural Oil Adducts in Alkyd-Based Varnish Emulsion and Effect on Rowan (Sorbus torminalis) Wood

In these days, preparation of eco-friendly wood surface coating agents has become important topic for environmental concerns. In this study, an alternative surface coating formulations was prepared with adducts of oils of apricot kernel (A), sesame (S) and grape seed (G) were mixed with oil modified alkyd-based synthetic varnish system. These emulsions were applied on Rowan (Sorbus torminalis) wood and exposed artificial UV irradiation. However, all emulsion coated samples show lower water sorptions regardless of conditions or level of treatments. Increasing adduct charges from 5.0% to 10% have not considerably effects for water sorptions. The reducing water sorption properties of 35.5%, 35.2% and 39.4% were obtained with 10% sesame oil-varnish coated samples of 10Sı and 10 Sıı in one- and two-time coatings and three-times coated samples of 5Sııı in 5.0% sesame oil-varnish emulsion coatings, respectively. Moreover, selected oil adducts into varnish had one and two point lowering effects on coated surface hardness (in 4H-5H levels). The UV exposure seems to not much influence on surface hardness properties. The similar tendency were also observed for cross-cut resistance that marginally similar adhesion (scratch resistance) for both control and UV exposured samples. Increasing coatings and charge of apricot kernel oil in varnish emulsion looks like more effective than other varnish formulations, in terms of gloss stability. However, increasing adducts charges and UV radiation time, have more less similar effects on all coated and UV irradiated samples.

Experimental investigation of a low-molecular-weight polymer coating agent for deep-sea oil and gas drilling

In order to solve the problems due to the thickening of drilling fluids at low temperatures caused by the use of high-molecular-weight polymer coating agents in offshore deep-sea oil and gas drilling, a low-molecular-weight polymer coating agent named PADA was synthesized with acrylamide, methacryloxyethyltrimethyl ammonium chloride, and 2-acrylamido-2-methyl propane sulfonic acid. The PADA polymer was characterized with Fourier transform infrared spectroscopy and gel permeation chromatography. The shale inhibition effects of the PADA polymer and associated mechanisms were investigated by shale recovery and expansion experiments, transmission electron microscopy observation, particle size and zeta potential analysis, and interlayer spacing measurements. In addition, the effects of the coating agent on the filter cakes and the low temperature rheological properties of bentonite mud were also tested, and the polymer biodegradability was evaluated. The results showed that the molecular weight of the PADA polymer was 265,000 D, which was significantly lower than that of the traditional coating agents. The PADA had similar effects as two typical commercial products CAP and HPAM on inhibiting the hydration dispersion of shales and performed better than another product PAM. The inhibition effect was achieved by the polymer absorption onto the clay particles through both hydrogen bonding and the electrostatic interactions. The viscosity of bentonite mud containing PADA was much lower than that of mud with other coating agents at 4 °C, so the serious thickening caused by traditional coating agents at a low temperature could be avoided. In addition, it is relatively easily biodegraded.

Effects of Seed Coating Agents on Some Agronomic Properties and Rhizobacterial Population of Vigna unguiculata

The agricultural activities had tremendously benefitted from the application of pesticides. However, various objectionable practices among farmers had exposed the soils, plant and its community of organisms to different level of toxicity. Therefore, this study evaluated the effects of seed coating agents on germination rate, shoot length, leave numbers and population of rhizobial and phosphate solubilizing bacteria (PSB) of beans plant (Vigna unguiculata). The mesocosm experiment was carried out in a greenhouse using a randomized block design with five replicates over the period of 5 weeks. The seed coating agents used were Imidadoprid-Thiram powder formulations and black powdery waste from dry-cell batteries. The seed coating agents were applied at the recommended rate value of 1.25 g/kg and at the rate that double the concentration of recommended field rate (2.50 g/kg). The application of Imidadoprid-Thiram at recommended rate and spent battery waste at the same rate did not have any significant effect (p > 0.05) on the germination of V. unguiculata as compared to the control. However, significant reductions (p < 0.05) in germination were observed in the seed coated with both coating agents at the rate above the recommendation value. Likewise, no significant effect (p > 0.05) of seed coating agents was observed on the average number of leaves of growing V. unguiculata seedling but significant reductions (p < 0.05) were observed in the shoot length of all the treated seedling as compared with control. Both Imidadoprid-Thiram and spent battery wastes were observed to have a significant negative (p < 0.05) effect on the average numbers of both rhizobia and PSB counts in the rhizosphere region of V. unguiculata, with effects more pronounced in higher doses.