Peculiarities of calculations of formation of extended sections of steel castings in disposable moulds with functional coating of definite microrelief

In the present article are considered the issues of influence of the microrelief of the working cavity surface of the sand-and-clay mould on the intensity of heat exchange and formation of the structure in the surface area of the metal blank, for prevention of hot cracks formation.

Analysis the Performance of Hydrophilic and Corrosion Resistant Coatings on the Distillation Desalination Tube in High Temperature Seawater

Distillation desalination can use solar energy and other renewable energy, it is one of the most potential technologies for desalination. However, distillation desalination system pervades problems such as low desalination efficiency and poor corrosion resistance. Based on our preliminary study (i.e., apply hydrophilic modification on the surface of distillation desalination tube can effectively improve desalination efficiency), this paper introduces a composite functional coating with the micro-arc oxidation (MAO) coatings sealed with hydrophilic organic coating-TiO2 hybrid sols (OT-MAO) by sol-gel process. Through contact angle measurement, scanning electron microscopy (SEM) and potentiodynamic polarization test to analyze and compare the performance of hydrophilicity and corrosion resistance of the MAO coatings and the OT-MAO composite coatings in high temperature seawater environment. The corrosion mechanism of the OT-MAO composite coatings was analyzed by electrochemical impedance spectroscopy (EIS). The results show that the OT-MAO composite coatings in high temperature seawater has much better hydrophilicity and corrosion resistance than the MAO coatings. This paper provides theoretical and technical reference for developing a new type of surface modified distillation desalination tube.

Improved Osteogenesis by Mineralization Combined With Double-Crosslinked Hydrogel Coating for Proliferation and Differentiation of Mesenchymal Stem Cells

In consideration of improving the interface problems of poly-L-lactic acid (PLLA) that hindered biomedical use, surface coatings have been explored as an appealing strategy in establishing a multi-functional coating for osteogenesis. Though the layer-by-layer (LBL) coating developed, a few studies have applied double-crosslinked hydrogels in this technique. In this research, we established a bilayer coating with double-crosslinked hydrogels [alginate–gelatin methacrylate (GelMA)] containing bone morphogenic protein (BMP)-2 [alginate-GelMA/hydroxyapatite (HA)/BMP-2], which displayed great biocompatibility and osteogenesis. The characterization of the coating showed improved properties and enhanced wettability of the native PLLA. To evaluate the biosafety and inductive ability of osteogenesis, the behavior (viability, adherence, and proliferation) and morphology of human bone mesenchymal stem cells (hBMSCs) on the bilayer coatings were tested by multiple exams. The satisfactory function of osteogenesis was verified in bilayer coatings. We found the best ratios between GelMA and alginate for biological applications. The Alg70-Gel30 and Alg50-Gel50 groups facilitated the osteogenic transformation of hBMSCs. In brief, alginate-GelMA/HA/BMP-2 could increase the hBMSCs’ early transformation of osteoblast lineage and promote the osteogenesis of bone defect, especially the outer hydrogel layer such as Alg70-Gel30 and Alg50-Gel50.

Durability Assessment of a Plasma-Polymerized Coating with Anti-Biofilm Activity against L. monocytogenes Subjected to Repeated Sanitization

Biofilm formation on food-contact surfaces is a matter of major concern causing food safety and spoilage issues to this sector. The aim of this study was to assess the durability of the anti-biofilm capacity of a plasma-polymerized coating composed of a base coating of (3-aminopropyl)triethoxysilane (APTES) and a functional coating of acrylic acid (AcAc). Coated and uncoated AISI 316 stainless steel (SS) plates were subjected to five sanitization cycles with sodium hypochlorite (0.05%) and peracetic acid (0.5%). The effectiveness of the coating for the inhibition of multi-strain Listeria monocytogenes biofilm formation was confirmed using a three-strain cocktail, which was grown on the SS plates at 12 °C for 6 days. Compared to the uncoated SS, relative biofilm productions of 14.6% on the non-sanitized coating, 27.9% on the coating after sanitization with sodium hypochlorite, and 82.3% on the coating after sanitization with peracetic acid were obtained. Morphological and physicochemical characterization of the coatings suggested that the greater anti-biofilm effectiveness after sanitization with sodium hypochlorite was due to the high pH of this solution, which caused a deprotonation of the carboxylic acid groups of the functional coating. This fact conferred it a strong hydrophilicity and negatively charged its surface, which was favorable for preventing bacterial attachment and biofilm formation.

Effect of ITO Content on Properties of Functional Graphene Coating on Cotton Fabric

In order to investigate the effect of indium tin oxide (ITO) on the performance of graphene functional coating on cotton fabric, different contents of ITO were added to the graphene coating system, and the effects of ITO content and curing time on various properties of graphene coating were studied. The results showed that the ITO particles adsorbed on the graphene sheets and filled the gaps between the graphene sheets, forming a dense conductive network, which could further improve the conductive performance of the functional coatings. When ITO content was 1.2%, the resistivity of the coating reached the lowest 1.8 Ω·cm, and the overall ultraviolet transmittance and reflectance were the lowest. With the increase of ITO content, the infrared reflectance will first decrease and then slowly increase, but the infrared reflectance is all below 0.5%. When the curing time reached 90 s, the resistivity and UV transmittance of cotton fabric coating decreased. With the extension of curing time, the coating on infrared reflectivity gradually increased, but the infrared reflectivity of the overall < 1%.

Characteristics of Functional Film Synthesized on the Cover Glass of Photovoltaic Modules

In this study, the characteristics of functional films were investigated according to the number of coatings and their heat treatment times. The functional coating films were deposited on glass substrates made of the same material as the cover glass of photovoltaic (PV) modules. Each film was coated once by brushing with a special silica-based solution, and each heat treatment was done using a hot-air fan for 2 min at 300 °C. The substrates were coated once, twice, and thrice, respectively, and were annealed once, twice, and thrice by drying and cooling alternately. The specimens were then analyzed for their anti-pollution properties, contact angles, light transmittance, and mechanical properties. The anti-pollution function was confirmed through a self-cleaning test, while the contact angle and light transmittance were examined using special equipment. Mechanical properties, including hardness and adhesion, were confirmed using the standard hardness testing method (ASTM D3363) such as those using an H-9H, F, HB, or B-6B pencil (Mitsubishi, Japan) and a standard adhesion testing method (ASTM D3359). It was confirmed that the film coated once yielded a very low contact angle of 8.9° and very good anti-pollution properties. Its adhesion and strength also showed high values of 5B and 9H, respectively.

Prediction of coating thickness for polyelectrolyte multilayers via machine learning

Layer-by-layer (LbL) deposition method of polyelectrolytes is a versatile way of developing functional nanoscale coatings. Even though the mechanisms of LbL film development are well-established, currently there are no predictive models that can link film components with their final properties. The current health crisis has shown the importance of accelerated development of biomedical solutions such as antiviral coatings, and the implementation of machine learning methodologies for coating development can enable achieving this. In this work, using literature data and newly generated experimental results, we first analyzed the relative impact of 23 coating parameters on the coating thickness. Next, a predictive model has been developed using aforementioned parameters and molecular descriptors of polymers from the DeepChem library. Model performance was limited because of insufficient number of data points in the training set, due to the scarce availability of data in the literature. Despite this limitation, we demonstrate, for the first time, utilization of machine learning for prediction of LbL coating properties. It can decrease the time necessary to obtain functional coating with desired properties, as well as decrease experimental costs and enable the fast first response to crisis situations (such as pandemics) where coatings can positively contribute. Besides coating thickness, which was selected as an output value in this study, machine learning approach can be potentially used to predict functional properties of multilayer coatings, e.g. biocompatibility, cell adhesive, antibacterial, antiviral or anti-inflammatory properties.