Dip-coating Method Research Articles

Impact of Dual-coated Silver Nanoparticle and Antibiotic Sutures on Wound Healing in Inflammatory Mouse Models

ABSTRACT Background: The use of silver nanoparticles (AgNPs) in biomedicine has emerged in a big way owing to its antibacterial and anti-inflammatory properties. We hypothesize that combining the AgNPs with antibiotics for coating sutures will enhance the antibacterial property of sutures with the added advantage of the immunomodulatory effect of AgNPs on tissue healing. Materials and Methods: Polyglactin sutures were coated with AgNPs using the dip-coating method. The uniform coating and morphology of AgNPs on the suture surface were confirmed using scanning electron microscopy (SEM). Each type of suture – polyglactin plain, antibiotic coated (Triclosan), AgNP coated, and dually coated (antibiotic and AgNP) – was assessed for their antibacterial properties against Gram-positive bacteria, Gram-negative bacteria, and anaerobes. These sutures were utilized in an abdominal and systemic inflammatory mice model for ileal anastomosis. The intestinal tissue was evaluated for acute and chronic inflammation and collagen deposition to assess the healing and inflammatory response. Results: The SEM and energy dispersive X-ray analysis showed successful coating of AgNPs on plain and antibiotic-coated sutures. In comparison with the other groups, the dually coated suture had the best in vitro antibacterial efficacy. The AgNP-coated sutures were able to decrease both acute and chronic inflammatory cell infiltration, but the collagen synthesis and deposition were enhanced. Conclusion: AgNPs can be coated on Polyglactin suture either alone or in combination with antibiotics with preserved antibacterial effects. The dual coating of sutures gives a synergistic antibacterial effect. The AgNP diminishes immune response in the presence of preserved extracellular matrix generation.

Preparation of Superhydrophobic and Multifunctional Sponges for Oil/Water Separation and Oil Absorption.

For settling the recycling problem of waste polyurethane sponges (PU) and environment pollution of oil spills simultaneously, this work exploited the multifunctional superhydrophobic PU materials via the dip-coating method, which were prepared by anchoring modified Fe3O4 and expandable graphite (EG) on PU sponges under the adhesion effect of polydimethylsiloxane (PDMS). The water contact angle and sliding angle of as-prepared PU sponges reached 154.1 ± 1.6 and 8°, respectively. Most importantly, the superhydrophobic PU sponges were endowed with the multipath oil treatment ability, which consisted of magnetically driven, gravity-driven, peristaltic pump-driven, and photothermally driven modes. Besides, the light oil absorption capacity, separation flux, and efficiency for superhydrophobic PU sponges reached 23.9 g/g, 27779 L m-2 h-1, and 99.5%, respectively. Owing to the photothermal conversion ability of Fe3O4 and EG, the temperature of superhydrophobic PU sponges was raised to 71.5 °C within 233 s under 1.2 solar irradiation (1200 W/m2), demonstrating its absorption potential for high-viscosity crude oils. In addition, the prepared sponges exhibited good chemical/mechanical stability, self-cleaning, and flame retardancy. In a nutshell, this article has evolved an environmentally benign and practical method for fabricating the multifunctional materials in oil spill treatment, which will efficiently accomplish the targets of low carbon and environmental management.

Electroless Copper Patterning on TiO2-Functionalized Mica for Flexible Electronics

The formation of conductive copper patterns on mica holds promise for developing cost-effective flexible electronics and sensing devices, though it is challenging due to the low adhesion of mica’s atomically flat surface. Herein, we present a wet-chemical method for copper patterning on flexible mica substrates via electroless copper deposition (Cu-ELD). The process involves pre-functionalizing 50 µm thick muscovite mica with a titanium dioxide (TiO2) layer, via a sol–gel dip-coating method with a titanium acetylacetonate-based sol. Photolithography is employed to selectively activate the TiO2-coated mica substrates for Cu-ELD, utilizing in situ photodeposited silver (Ag) nanoclusters as a catalyst. Copper is subsequently plated using a formaldehyde-based Cu-ELD bath, with the duration of deposition primarily determining the thickness and electrical properties of the copper layer. Conductive Cu layers with thicknesses in the 70–130 nm range were formed within 1–2 min of deposition, exhibiting an inverse relationship between plating time and sheet resistance, which ranged from 600 to 300 mΩ/sq. The electrochemical thickening of these layers to 1 μm further reduced the sheet resistance to 27 mΩ/sq. Finally, the potential of Cu-ELD patterning on TiO2-functionalized mica for creating functional sensing devices was demonstrated by fabricating a functional resistance temperature detector (RTD) on the titania surface.

Oil-Resistant Underoil Superhydrophilic Metallic Foams for Lampblack Prefiltration.

Superwetting/repelling coatings have been utilized to address the issue of oil contamination on lampblack prefiltration metallic foam by both academia and industry. Nevertheless, the widely adopted superamphiphobic coatings are currently costly and suffer from poor wear resistance. In this study, we propose an oil-resistant underoil superhydrophilic (LSH) coating by a dip-coating method. The subsequent heating process at 200 °C for 5 min strengthens the designed coating based on lithium polysilicate cross-linking reinforcement. The LSH coating with a minimal water contact angle up to 3.4° under soybean oil can spontaneously achieve oil desorption within 7 s under water. Moreover, the coating retains its superhydrophilicity after enduring 900 friction cycles under a 500 g load or being immersed in 50 °C soapy water for 48 h. Hence, the LSH coating with great durability on metallic foam for lampblack prefiltration resulted in a 9.3% decrease in the oil absorption weight ratio after a 17-day cooking test. This work underscores the potential application of the LSH coating in lampblack prefiltration components, presenting promising technological advancements in self-cleaning for the catering industry.

Milk exosome-infused fibrous matrix for treatment of acute wound

To provide an advanced therapy for wound recovery, in this study, pasteurized bovine milk-derived exosomes (mEXO) are immobilized onto a polydopamine (PDA)-coated hyaluronic acid (HA)-based electrospun nanofibrous matrix (mEXO@PMAT) via a simple dip-coating method to formulate an mEXO-immobilized mesh as a wound-healing biomaterial. Purified mEXOs (∼82 nm) contain various anti-inflammatory, cell proliferation, and collagen synthesis-related microRNAs (miRNAs), including let-7b, miR-184, and miR-181a, which elicit elevated mRNA expression of keratin5, keratin14, and collagen1 in human keratinocytes (HaCaT) and fibroblasts (HDF). The mEXOs immobilized onto the PDA-coated meshes are gradually released from the meshes over 14 days without burst-out effect. After treatment with HaCaT and HDF, the degree of in vitro cell migration increases significantly in the mEXO@PMAT-treated HaCaT and HDF cells compared to the unmodified or PDA-coated meshes-treated cells. Additionally, the mEXO@PMAT provides significantly faster wound closure in vivo without notable toxicity. Thus, the sustained liberation of bioactive mEXO from the meshes can effectively enhance cell proliferation in vitro and accelerate wound closure in vivo, which could be harnessed mEXO@PMAT as a promising wound-healing biomaterial.

Electromagnetic interference shielding, mechanical, and flame retardant behaviors of Ti3C2Tx-MXene/glass fabric epoxy hybrid composites

This study investigates the manufacturability and electromagnetic shielding effectiveness (EMI-SE) of Ti3C2Tx/MXene-coated glass fabric laminated composites for aerospace applications. MXene-coated fabrics were produced using a dip-coating method. The effects of varying dipping counts (5 and 10) and different configurations of fabric arrangements on the EMI-SE of the composites in the X-band range (8.2–12.4 GHz) were investigated. Glass fabrics with 5 and 10 dips showed average surface resistances of 38.56 Ω/sq and 23.17 Ω/sq, respectively. In both the 5- and 10-dip composite sets, the total EMI-SE increased with the number of MXene-coated glass fabric layers in the composite. The 5MXC5 and 10MXC5 specimens, with conductive fabric in all layers, had average total shielding effectiveness (SET) of −18.75 dB and −23.21 dB, respectively. These values are 147.05 % and 205.80 % higher than the neat glass fiber-epoxy composite (C1). Flammability, bending, ILSS, and hardness tests were conducted on these composites. Increasing the MXene content reduced the burning rate, with 10MXC5 exhibiting a 26.31 % lower burning rate compared to C1. However, higher MXene content slightly decreased bending and ILSS values. Optical microscope examination of the fracture surfaces revealed that this decrease was due to delamination damage.

Mechanoluminescent/Electric Dual-Mode Sensors Enabled by Trace Carbon Nanotubes.

Mechanoluminescence (ML)-based sensors are emerging as promising wearable devices, attracting attention for their self-powered visualization of mechanical stimuli. However, challenges such as weak brightness, high activation threshold, and intermittent signal output have hindered their development. Here, a mechanoluminescent/electric dual-mode strain sensor is presented that offers enhanced ML sensing and reliable electrical sensing simultaneously. The strain sensor is fabricated via an optimized dip-coating method, featuring a sandwich structure with a single-walled carbon nanotube (SWNT) interlayer and two polydimethylsiloxane (PDMS)/ZnS:Cu luminescence layers. The integral mechanical reinforcement framework provided by the SWNT interlayer improves the ML intensity of the SWNT/PDMS/ZnS:Cu composite film. Compared to conventional nanoparticle fillers, the ML intensity is enhanced nearly tenfold with a trace amount of SWNT (only 0.01wt.%). In addition, the excellent electrical conductivity of SWNT forms a conductive network, ensuring continuous and stable electrical sensing. These strain sensors enable comprehensive and precise monitoring of human behavior through both electrical (relative resistance change) and optical (ML intensity) methods, paving the way for the development of advanced visual sensing and smart wearable electronics in the future.

Robust, intelligent photochromic cotton fabrics with superamphiphobicity and expedient UV detection ability

Multifunctional photochromic cotton fabrics have enormous application potential in our daily lives, but still suffer from poor durability, slow coloration, tedious fabrication process, and short service life. The hydrophilic and polysaccharide characteristics of cotton fabrics make them vulnerable to bacteria adhesion and proliferation. Herein, intelligent photochromic cotton fabrics featured with durable superamphiphobicity are fabricated by in situ growth of ZIF-8 nanoparticles encapsulating spirooxazine (SP) photochromic dyes on the fabric surface, followed by low surface energy treatment using a fluorocarbon resin (FR) via a dip-coating method. The resultant SP@ZIF-8/FR cotton fabrics exhibit superamphiphobicity with contact angles of over 150° to both water and oils (surface tension ≥30 mN/m). When exposed to UV light, the fabric rapidly changes its color from white to blue within 10 s and fades in 2 min under visible room light. The developed SP@ZIF-8/FR coating is durable against numerous damages in daily usage, such as machine laundry, abrasion and UV irradiation, without losing photochromic and superamphiphobic properties. The high durability and excellent reversible color response allow the coated fabric to intuitively and quantitatively monitor outdoor UV intensity. Owing to the presence of ZIF-8, the treated fabrics also show excellent antibacterial property with antibacterial rates of over 99 % against both E. coli and S. aureus. The developed fabric coating can be engineered to visually assess the UV intensity in the outdoor environment.

Synthesis and characterisation of high-purity alumina achieved through a dip coating process

ABSTRACT This study focuses on the synthesis of alumina using a modified citrate method. The chelation process involved thermal activation through biphasic drops, employing the hydrated aluminium nitrate precursor and citric acid complex. The thermal behaviour of the resulting gel was investigated using DSC/TGA followed by FTIR, which revealed absorption bands at distinct temperatures leading up to the formation of white crystallised alumina powder at 1000°C. Structural analysis via XRD parameters indicated that the obtained sample is refined in the hexagonal system with the R-3C space group. SEM observations demonstrated morphology akin to an overlapping hive, highlighting significant stoichiometric purity. The semi-colloidal sol was applied in a dip-coating method to reinforce the matrix of a steel substrate, specifically E335. SEM-EDS analyses revealed the adhesion recorded as a brittle intermetallic phase. Additionally, a transformation of 22% haematite to magnetite was observed under the conditions of coating.

Sustainable rewritable paper based on photoresponsive tungsten oxide quantum dots for anti-counterfeiting and waterproofing

Ink-free printing using photochromic paper has emerged as a promising technology for information recording, transmission, and secure interaction applications. Tungsten oxide quantum dots (WO3 QDs), with their rapid UV response, excellent photochemical stability, and outstanding fatigue resistance, exhibit significant potential as an ink-free medium in the construction of sustainable rewritable paper. However, challenges such as low binding force, poor stability, and weak scalability limit the development of reversible photochromic paper based on WO3. In this study, a novel sustainable rewritable paper based on a scalable strategy of covalent modification and hydrophobic layer protection has been reported. Specifically, cellulose papers modified with silane coupling agent were directly grafted with amino-modified WO3 QDs by covalent bonding through the addition reaction between epoxy and amine groups. Subsequently, the sustainable rewritable paper was obtained by the deposition of hydrophobic layer of polydimethylsiloxane (PDMS) via a dip-coating method. The rewritable paper exhibits exceptional properties, including high color contrast, extended color-retention (over 21 days), good rewritability (20 cycles) and excellent resistance to water or stains. Based on ink-free writing technology, the photo-responsive rewritable papers were utilized for anti-counterfeiting and encryption or decryption, demonstrating their great potential for information recording, storage, and security protection.

High-Performance Wearable Joule Heater Derived from Sea-Island Microfiber Nonwoven Fabric.

A three-dimensional (3D) hierarchical microfiber bundle-based scaffold integrated with silver nanowires (AgNWs) and porous polyurethane (PU) was designed for the Joule heater via a facile dip-coating method. The interconnected micrometer-sized voids and unique hierarchical structure benefit uniform AgNWs anchored and the formation of a high-efficiency 3D conductive network. As expected, this composite exhibits a superior electrical conductivity of 1586.4 S/m and the best electrothermal conversion performance of 118.6 °C at 2.0 V compared to reported wearable Joule heaters to date. Moreover, the durable microfiber bundle-PU network provides strong mechanical properties, allowing for the stable and durable electrothermal performance of such a composite to resist twisting, bending, abrasion, and washing. Application studies show that this kind of Joule heater is suitable for a wide range of applications, such as seat heating, a heating jacket, personal thermal management, etc.

Giant Cushioning Effect in Facile Polymer/Nanoclay-Coated Flexible Polyurethane Foams.

In this work, a flexible polyurethane (PU) foam/polymer/clay (PUF/PAASep) composite is prepared via a simple dip-coating method. The composite exhibits excellent damping properties under quasi-static compression, vibration transmissibility, and impact resistance. For the composite preparation, sepiolite (Sep) dispersion in a polyacrylic acid (PAA) solution is first homogenized and evaluated using microscopy, and the obtained PAASep suspension is used to coat the PU foam uniformly for optimization of the quasi-static mechanical performance of the foam composites. The PU foam struts coated with 1 wt % PAA and 3 wt % sepiolite are strengthened, resulting in an 8-fold improvement of the stiffness and three-times increase of the impact force resistance compared to the uncoated PU foams. More importantly, the PU foam composites show a remarkable vibration damping capability, with the loss modulus 57 times that of the uncoated PU foams, enabled by micro friction and stick-slip effects mediated by the PAASep coatings. The facile prepared PAASep-coated PU foams have significant potential for cushioning, packaging, and broad engineering applications involving energy absorption.

Influence of sulfurization temperature on grain growth in Cu2ZnSnS4 thin films synthesized for solar cell applications

Copper-zinc-tin-sulfur (CZTS) thin films, prepared through a dip-coating solution method, present a highly attractive option as absorber materials for thin-film solar cells. This is due to their affordability, environmentally friendly composition, and abundant availability of raw materials. Although films processed with hydrazine-based solutions have achieved the highest efficiency of approximately 12.6%, the toxic and carcinogenic nature of hydrazine negates these advantages. In the ongoing global research on solution-based processing methods, the size of the grains has emerged as a critical factor in the fabrication of efficient solar cells. In our study, we have successfully prepared CZTS thin films with a pure kesterite phase, characterized by large micro-sized grains, using a dip-coating process with an ethanol-based precursor solution, followed by sulfurization. We investigated how the grain size evolves with varying sulfurization temperatures. Notably, we observed that increasing the temperature led to larger and more uniform grain growth. These results underscore the potential of our approach for the straightforward production of high-quality films with sizable grains, ultimately enhancing their photosensitivity and making them a promising candidate for efficient solar cell applications.

Enhanced oxidation resistance and electrochemical performance of PEMFC gas diffusion layer through [EMIM][TFSI] ionic liquid coating

The performance and durability of Proton Exchange Membrane Fuel Cells (PEMFCs) are critically hindered by the oxidation susceptibility of graphite felt gas diffusion layers (GDLs). This study addresses this challenge by employing a protective coating of 1-Ethyl-3-methylimidazolium Bis(trifluoromethyl sulfonyl)imide ([EMIM][TFSI]) on the GDL through a dip-coating method, followed by thermal curing to ensure uniform distribution and strong adherence. Comprehensive characterization, including Scanning Electron Microscopy (SEM), X-ray Diffraction (XRD), X-ray Photoelectron Spectroscopy (XPS), and Fourier-Transform Infrared Spectroscopy (FTIR), confirmed the homogeneous coating, adhesion, and maintained porosity and gas diffusion properties of the GDL. The coated GDL exhibited a substantial increase in oxidation resistance, resulting in higher hydrophobicity with a contact angle of approximately 131°, compared to 96° for the uncoated GDL. Electrochemical analyses revealed that the [EMIM][TFSI]-coated GDL achieved a current density of 27 mA cm−2 at 0.925 V, surpassing the 19 mA cm−2 of the uncoated GDL at 0.91 V during cyclic voltammetry (CV) analysis. This study is limited by the short-term stability tests and the specific environmental conditions under which the experiments were conducted. Future work will focus on optimizing the coating process for varied environmental conditions and exploring the scalability of this technique for practical applications.

Synthesis and characterization of amine-functionalized graphene as a nitric oxide-generating coating for vascular stents.

Drug-eluting stents are commonly utilized for the treatment of coronary artery disease, where they maintain vessel patency and prevent restenosis. However, problems with prolonged vascular healing, late thrombosis, and neoatherosclerosis persist; these could potentially be addressed via the local generation of nitric oxide (NO) from endogenous substrates. Herein, we develop amine-functionalized graphene as a NO-generating coating on polylactic acid (PLA)-based bioresorbable stent materials. A novel catalyst was synthesized consisting of polyethyleneimine and polyethylene glycol bonded to graphene oxide (PEI-PEG@GO), with physicochemical characterization using x-ray diffraction, Raman spectroscopy, Fourier transform infrared spectroscopy, and thermogravimetric analysis. In the presence of 10 μM S-nitrosoglutathione (GSNO) or S-nitroso-N-acetylpenicillamine (SNAP), PEI-PEG@GO catalyzed the generation of 62% and 91% of the available NO, respectively. Furthermore, PEI-PEG@GO enhanced and prolonged real-time NO generation from GSNO and SNAP under physiological conditions. The uniform coating of PEI-PEG@GO onto stent material is demonstrated via an optimized simple dip-coating method. The coated PLA maintains good biodegradability under accelerated degradation testing, while the PEI-PEG@GO coating remains largely intact. Finally, the stability of the coating was demonstrated at room temperature over 60 days. In conclusion, the innovative conjugation of polymeric amines with graphene can catalyze the generation of NO from S-nitrosothiols at physiologically relevant concentrations. This approach paves the way for the development of controlled NO-generating coatings on bioresorbable stents in order to improve outcomes in coronary artery disease.

Strategically engineered multifunctional graphene oxide hybrid nanomaterials for efficient catalytic degradation and emerging contaminants treatment

The use of functional textiles is growing in all fields of science and technology. Surface functionalization is mainly used to impart conventional textiles with new functionalities and improved performances. In the present study, a cobalt ferrite nanoparticle/graphene oxide (CoFe2O4/GO) coated polyethylene terephthalate (PET) fabric with excellent catalytic and antibacterial properties, has been successfully developed. The PET-coated CoFe2O4/GO samples, ranging from 1 % to 5 % wt. were obtained using a simple dip-coating method in CoFeO/GO solution (1 mg/mL), and were investigated through several physiochemical characterization techniques. CoFe2O4/GO and PET fabric have been shown to establish an interfacial connection by Fourier transform infrared spectroscopy (FTIR). X-ray diffraction (XRD) results showed that CoFe2O4/GO coating did not affect the PET crystallinity and that CoFe2O4/GO hybrid was incorporated in the PET samples, which was proved as well by the morphological study through Scanning electron microscopy (SEM). Furthermore, thermogravimetric characterisation (TGA) verified that the coating does not change or impair the quality of the fibre and that the PET@CoFe2O4/GO as made is thermally stable. Tensile strength tests demonstrated that coated fabrics exhibited outstanding mechanical properties in comparison with pristine PET. Moreover, the coated PET@CoFe2O4/GO fabric was used as a model catalytic system for peroxymonosulfate (PMS) activation in the rhodamine B (RhB) degradation reaction. Total Organic Carbon (TOC) measurements showed that TOC removal reached 89.82 % in only 12 min reaction. The results confirmed that the coated fabrics exhibited high catalytic performances, good stability and reusability in consecutive degradation experiments with a degradation rate over 60 % even after 7 degradation cycles; Moreover, it is easily and simply separated from the mixture, by removing the textile sample from the aqueous solution. It is worth mentioning that the PET@CoFe2O4/GO fabrics showed outstanding antibacterial activity against both Staphylococcus aureus (Gram-positive) and Escherichia coli (Gram-negative) bacteria with an inhibition diameter zone of up to 13 mm for PET@CoFe2O4/GO (5 %). Overall, these findings are of great importance as they permit the development of a novel multifunctional textile fabric, combining anti-bacterial activity, catalytic performance and mechanical properties. The study provides a textile-based catalyst with improved catalytic performance, re-usability in consecutive degradation reactions and easy catalyst separation compared to traditional supports. Thus, a huge potential application in several fields such as medicine, heterogeneous catalysis, and wastewater treatment.

Development of a Multiparticulate Metal-Organic Framework/Textile Fiber Swatch.

The versatility of metal-organic frameworks (MOFs) has led to groundbreaking applications in a wide variety of fields, especially in the areas of energy, environment, and sustainability. For example, MOFs can be designed for high uptake of toxic gases and pollutants, such as CO2, NH3, and SO2, but designing a single MOF that shows tangible uptake for all of these gases is challenging due to the differences in the chemical and physical properties of these molecules. To this end, integrating multiple MOFs onto textile fibers and crafting various structures have emerged as pivotal developments, enhancing framework durability and usability. MOF composites prepared on readily available textile fibers offer the flexibility essential for critical applications, including heterogeneous catalysis, chemical sensing, toxic gas adsorption, and drug delivery, while preserving the unique characteristics of MOFs. This study introduces a scalable and adaptable method for seamlessly embedding multiple high-performing MOFs onto a single textile fiber using a dip-coating method. We explored the uptake capacity of these multi-MOF composites for CO2, NH3, and SO2 and observed a performance similar to that of traditional powdered materials. Along with harmful gas adsorption, we also have evaluated the permeation and reactivity of these MOF/textile composites toward chemical warfare agents (CWAs) like GD (soman), HD (mustard gas), and VX. In combination, these results demonstrate a fundamental advancement toward establishing a consistent strategy for the hydrolysis of nerve agents in real-world scenarios. This approach can substantially increase the protection toward CWAs and enhance the effectiveness of protective equipment such as fabrics for protective garments. This dip-coating method for the integration of multiple MOFs on a single textile fiber unlocks a wealth of possibilities and paves the way for future innovations in the deployment of MOF-based composites.

Interface construction of crosslinked hyperbranched polyamidoamine between silver layer and poly(meta-phenylene isophthalamide) fiber to enhance conductivity and its resilience to adverse conditions

High-performance silvered poly(meta-phenylene isophthalamide) (PMIA) fiber can be applied in antistatic, conductive, electromagnetic interference shielding and other fields, whereas achieving good interface bonding of silver layer to PMIA matrix remains a grand challenge. This paper studies a method of constructing multi-structure interface between silver layer and PMIA fiber. First, crosslinked hyperbranched polyamidoamine (HPAMAM), referred to as xHP-Qy, was introduced onto PMIA by means of a dip-coating method. Then, the modified fiber was surface metallized by silver ammonia solution and glucose solution to prepare a silver-coated fiber. The structure, morphology and properties of as-prepared materials were characterized systematically. The results show that the final fiber exhibits a low electrical resistivity (5.95 × 10−5 Ω·cm) without sacrificing the thermal stability and mechanical performance of the PMIA itself, which is attributed to the distinct antenna-shaped structure of xHP-Qy between PMIA matrix and Ag layer. In addition, the functionalized composite fiber preserves low resistivity even after subjecting harsh environment and mechanical deformation. The strategy paves a promising avenue for the fabrication of high-performance fiber with enormous potential application for electromagnetic interference shielding, electrical heating and flexible sensor materials.

Titania and zirconia ceramic nanofiltration membrane fabrication by coating method on mullite and mullite-alumina microfiltration supports for industrial wastewater treatment

Industrial wastewater treatment increasingly relies on membrane separation, with ceramic membranes offering many advantages such as thermal stability and pH resistance. The resistance of ceramic membranes to extreme pH conditions indicates their ability to maintain structure and performance when exposed to highly acidic or alkaline environments. A high-permeability ceramic nanofiltration membrane was developed, boasting excellent rejection rates through a multilayer asymmetric design. Initially, two tubular porous supports, mullite and mullite-alumina, with a weight percent of 50, were fabricated using the extrusion method. Subsequently, a colloidal sol of titania (TiO2) and titania-zirconia (TiO2- ZrO2) was prepared via the sol–gel method and coated on the ceramic supports using the dip-coating method. After analyzing the membrane microstructure using SEM, XRD, and BET, the efficiency of the membranes in treating synthetic oily wastewater was evaluated. The results underscore the significant impact of the Donnan exclusion mechanism on the rejection of nanofiltration (NF) membranes. An increase in pressure led to a rise in rejection rates up to 7 bars. The Chemical Oxygen Demand (COD) rejection for mullite-titania zirconia (MTZ) and mullite-alumina-titania zirconia (MATZ) membranes was 98.65 % and 98 %, respectively. The pure water permeability test results for mullite and mullite-alumina supports, as well as MTZ and MATZ membranes, were recorded as 254, 382, 70, and 89 L bar-1m-2h−1, respectively.

Influence of casein on the degradation process of polylactide-casein coatings for resorbable alloys

This study used the dip-coating method to develop a new biocompatible coating composed of polylactide (PLA) and casein for ZnMg1.2 wt% alloy implants. It evaluated its impact on the alloy's degradation in a simulated body fluid. After 168 h of immersion in Ringer's solution, surface morphology analysis showed that the PLA-casein coatings demonstrated uniform degradation, with the corrosion current density measured at 48 µA/cm2. Contact angle measurements indicated that the average contact angles for the PLA-casein-coated samples were below 80°, signifying a hydrophilic nature that promotes cell adhesion. Fourier-transform infrared spectroscopy (FTIR) revealed no presence of lactic acid on PLA-casein coatings after immersion, in contrast to pure PLA coatings. Pull-off adhesion tests showed tensile strength values of 7.6 MPa for pure PLA coatings and 5 MPa for PLA-casein coatings. Electrochemical tests further supported the favorable corrosion resistance of the PLA-casein coatings, highlighting their potential to reduce tissue inflammation and improve the biocompatibility of ZnMg1.2 wt% alloy implants.