Dipping Solution Research Articles

Evaluation of the microbial control efficacies of commonly used home-drying and storage practices of dried peaches

This study investigated the microbial control efficacy of five pre-drying treatments and three drying protocols commonly used by small and medium dried peach processors. Salmonella spp. and Enterococcus faecium (Ef) were used for inoculation. Except for blanching, 10-min dipping treatments in ascorbic acid, citric acid, lemon juice, or sodium metabisulfite reduced Salmonella by 0.54–2.40 Log CFU/peach half. The detection of Salmonella in used dipping solution highlighted the potential risks of cross-contamination during dipping treatments. Drying in an oven or a dehydrator at 60 °C reduced the inoculated Salmonella and Ef by 1.47 and 0.91 Log CFU/peach half. The internal temperature of peach halves reached during sun-drying is lower than the internal temperature reached during oven- or dehydrator-drying. Exposure to simulated sunlight (UV) could resulted in up to 6.75 Log reduction of Ef with higher reduction observed from peach halves with lower water activities. Salmonella and Ef could survive on dried peaches for up to 90 days with greater reduction observed on dried peaches made with sulfur dioxide treatment and at ambient temperature. Ef showed higher resistance than Salmonella in two pre-drying dipping treatments and survived better than Salmonella on dried peaches made without sulfur treatment at ambient temperature.

On demand oil/water separation enabled by microporous ultra-thin aluminum foil with asymmetric wettability

The novel metal membranes with multifunctionality and adaptability have become the new strategies in the field of oil/water separation. Distinct from other multifunctional membranes, the novel metal membranes that are less time-consuming and cost-efficient can perform on-demand oil/water separation in the large scale separation environment. However, obtaining an ultra-thin metal membrane with multifunctionality and adaptability for application remains a challenge. Taking advantage of both the atypical localized etching and solution dipping method, a novel MUAF membrane was prepared in our study. With the vertical capillary effect and the papillary-like micro structures, this novel membrane displays asymmetric wettability and achieves the efficient separation of light and heavy oil/water mixed solutions. The whole separation process was driven by gravity, without requiring extra energy. The mechanism of oil/water separation was also investigated by the intrusion pressure. Our work presents a simple and rapid method that uses ultra-thin AF to fabricate a novel asymmetric wettability metal membrane that is promising for future application in the large scale separation environment. This membrane also has application potential for oil storage and transportation.

Effects of chitosan-based coatings incorporated with ɛ-polylysine and ascorbic acid on the shelf-life of pork

Chitosan is a food thickener with film-forming ability and antibacterial activity. ɛ-Polylysine is a preservative with broad-spectrum antibacterial activity. Ascorbic acid is a food antioxidant. In this study, pork chunks were treated with four dipping solutions, i.e. purified water (control), 0.2% ascorbic acid (treatment-1), 0.02% ɛ-polylysine (treatment-2), and 0.4% chitosan + 0.02% ɛ-polylysine + 0.2% ascorbic acid (treatment-3), and stored at 3 °C for 12 days. All treatments suppressed bacterial growth, increases in pH and total volatile basic nitrogen (TVB-N) and thiobarbituric acid reactive substances and decreases in the red indices of pork chunks compared with the control during refrigeration. Based on the national standards of total bacterial number and TVB-N of pork, treatment-3 extended the shelf-life of pork chunks by six days compared with the control. The results verified that chitosan-based coatings may be a practical method for the preservation of pork chunks during refrigeration.

Copper and cobalt loading carbon as an efficient catalyst for the electroreduction CO2 to CO and hydrocarbons

Electrocatalytic reduction of carbon dioxide to syngas and hydrocarbons is a promising way to reduce CO2 emissions. In this work, Cu2+ was introduced into the synthesis process of ZIF-67, and a series of CoCu-N-C composites were synthesized by adjusting the molar ratio of Co/Cu and calcination temperature. X-Ray Diffraction (XRD) and X-ray Photoelectron Spectroscopy (XPS) tests showed that the metal mainly loaded on the carbon matrix in the form of metallic Co/Cu, and a part metal was doped into the carbon matrix in the form of M-N. Transmission Electron Microscopy (TEM) showed that the metallic Co/Cu uniformly distributed on the carbon matrix because of the wrapping by carbon matrix. Linear Sweep Voltammetry (LSV) test displayed that CoCu-N-C composites exhibited higher electrocatalytic activity than Co-N-C for CO2 reduction. The Faradic efficiency (FE%) of CH4, CO and H2 of CoCu(1:3)-N-C-900 at -0.53 V(vs. RHE) was 21%, 35% and 30%, respectively. Then the effect of Co/Cu, calcination temperature and reduction potential on the FE% of CH4, CO and H2 was investigated. A wider range of CO/H2 ratio from 0.29 to 1.17 can be obtained by adjusting Co/Cu. Mechanism was explored through the acid etching experiments, KSCN solution dipping and XPS spectra analysis. Results indicated that the introduction of metallic Cu greatly promoted the shift of electron in CoCu(1:3)-N-C-900 and its adsorption capacity towards CO2, ultimately improving its electrocatalytic activity. This work provided a refined paradigm for designing earth-abundant electrocatalysts used to effectively catalytic CO2 to CO and hydrocarbons.

Chemical Passivation Stabilizes Zn Anode

AbstractAqueous zinc ion batteries are an attractive option for grid‐scale energy storage, which is vital to the integration of renewable energy resources with the electric energy infrastructure. The cycling stability of aqueous ZIBs is determined by the electrochemical reversibility of Zn anode, which is often deteriorated by its corrosion and dendritic Zn deposition. Here, a simple and rapid surface passivation strategy that can drastically improve the cycling stability of Zn anodes is demonstrated. For example, a dip in KMnO4 solution readily forms a continuous, conformal, and robust protective layer on the native Zn surface, leading to a more uniform plating/stripping process, increased corrosion resistance, and tolerance to manufacturing and processing defects on Zn metal electrodes. The Zn electrode cycling stabilities at 1 mA cm−2 and 1 mA h cm−2 are extended by ≈40 times. In full battery tests in the configuration of Zn||β‐MnO2, the full cell with passivated Zn anode exhibited a capacity retention of 68.7% after 300 cycles at a current density of 1.0 A g−1, while the cell with untreated Zn anode can only retain 7.4% of capacity under the same conditions.

Effect of aluminium acetyl acetonate on the hydrogen and nitrogen permeation of carbon molecular sieves membranes

With a growing interest in hydrogen as energy carrier, the efficient purification of hydrogen from gaseous mixtures is very important. This paper addresses the separation of hydrogen using Carbon Molecular Sieves Membranes (CMSM), which show an attractive combination of high permeability, selectivity and stability. Supported CMSM containing various amounts of aluminium have been prepared from novolac and aluminium acetyl acetonate (Al(acac)3) as carbon and alumina precursors. The thickness of the CMSM layers depend on the content of Al(acac)3 in the dipping solution, which also has influence in the pore size and pore size distribution of the membranes. The permeation properties of the membranes against the Al content in the membrane follows a volcano shape, where the membrane containing 4 wt (%) of Al(acac)3 has the best properties and was stable during 720 h for hydrogen at 150 °C and 6 bar pressure difference. All the CMSM have permeation properties well above the Robeson Upper limit.

Does Irrisept Dipping/Irrigation Adversely Affect the Hydrophilic Coating of Titan Implants?

ABSTRACT Introduction Prosthetic infections occur in 1-3% of virgin implants. Titan penile prostheses (PP) have a hydrophilic coating that can absorb any antibiotic/antifungal solution for infection prevention. The ideal solution for dipping non-coated implants is yet to be described, however, reports of various solutions exist. Chlorhexidine gluconate is a very broad spectrum antibacterial, antifungal and antiviral solution that has been used for skin preparation for surgery because of its excellent profile for known pathogens. Irrisept is the first and only chlorhexidine 0.05% solution that has been FDA cleared for intra-corporal wound lavage in humans. When considering a new dipping solution, we must always weigh the effectiveness of any dipping solution with the caustic properties of the solution on the device and tissue. Objective The purpose of this experiment is to determine the effects of Irrisept solution on Coloplast's hydrophilic coating incorporated on the Titan penile prosthesis (PP). Methods Pre-connected Titan PP product including both pumps and cylinders were tested. The Titan PP was soaked in Irrisept solution and normal saline for 1, 15, 30 and 60 minutes. After soaking, all parts were dried for 15 minutes in a 35°C oven, and then went through the Congo Red Dye Test. Congo Red dye testing was performed per the approved FDA test method for ensuring product reliability. (Coloplast’ internal Test Method.) Results All the PPs tested achieved satisfactory coating results. There was no noticeable effect or difference of coating adherence between the saline soaked control and Irrisept soaked devices. And there was no noticeable effect or difference of coating adherence between different soaking time. (Figure 1 Congo Red stain) Conclusions Soaking the Titan PP in Irrisept solution does not effect the hydrophilic coating of the implant when compared to saline. There was also no difference in hydrophilic coating compared to saline controls at various times of dipping (1, 15, 30 and 60 min). Disclosure Yes, this is sponsored by industry/sponsor: Coloplast Clarification: Industry initiated, executed and funded study Any of the authors act as a consultant, employee or shareholder of an industry for: Coloplast

Storage Stability and Consumer Acceptability of Dried Apple: Impact of Citric Acid, Potassium Sorbate and Moringa oleifera Leaf Extract Powder.

The effects of a dipping solution containing 2.0% citric acid (CA) and 0.1% Moringa oleifera leaf extract powder (MOLEP) (CMO) and another dipping solution with CA at 2.0%, MOLEP at 0.1% and potassium sorbate (PS) at 0.2% (CMOP) on the storage stability over 3 months and consumer acceptability of dried apple slices were evaluated. Microbiological testing (osmophilic yeast, Escherichia coli and yeast and moulds) and total acidity testing were performed and physical tests, namely moisture analysis, water activity (Aw), texture analysis and colour were performed at day 0, day 60 and day 120. Moisture increased over the shelf-life period, which affected the extensibility of the pre-treated dried sliced apples negatively. The CMO pre-treatment was effective in reducing browning and inhibiting microbial growth on the dried apple slices over the storage period. A consumer acceptability test was performed using the nine-point hedonic scale. The dried sliced apples pre-treated with the 2% CA and 0.1% MOLEP powder water solution were acceptable to consumers with regards to colour, texture and taste.

New insights into the cell wall preservation by 1-methylcyclopropene treatment in harvest-ripe strawberry fruit

The purpose of the present work was to provide novel knowledge about the mechanisms underlying the preservation of strawberry fruit by 1-methylcyclopropene (1-MCP) treatment during storage. Harvest-ripe strawberries were treated with 1-MCP for ten hours at 22 °C and then stored for ten days at 4 °C and two days at 20 °C. 1-MCP treatment significantly delayed the loss of fruit firmness and the accumulation of anthocyanins during storage, whereas sustained pH, titratable acidity, total sugars, and phenolic compounds values. 1-MCP treatment reduced the in vitro growth of fungal pathogens Botrytis cinerea and Rhizopus stolonifer when using isolated fruit cell walls as only carbon source. Also, 1-MCP treatment was effective in delaying the appearance of fungal lesions and reducing their severity in comparison with non-treated fruit. 1-MCP treated fruit showed higher amounts of ionically bounded pectins and hemicellulose fractions than controls. Treated fruit showed an increase of pectin methylesterase activity, and the inhibition of polygalacturonase, β-galactosidase, α-arabinofuranosidase, and β-xylosidase activities. 1-MCP application modified the expression of relevant genes related to strawberry fruit firmness, increasing the FaPME1 and FaXTH1 mRNA abundance and down-regulating FaPG1, FaPLC, and FaXTH2 expression. Treatment delayed the in vitro cell wall swelling and the collapse of the hemicellulose-cellulose mesh during storage. The effect of 1-MCP on the cell wall composition and its accessibility to necrotrophic pathogens through an up-regulation of endogenous pectin methylesterases and xyloglucan transglycosylases and a down-regulation of lyases and hydrolases is the first report in commercial-ripe strawberries. Moreover, the effect of 1-MCP treatment combined with a dip in a CaCl2 solution on the firmness of strawberry fruit was evaluated. As a result, 1-MCP/CaCl2 treatment rendered significantly firmer fruit when compared with control, and also with 1-MCP, or CaCl2 individual applications.

A Shallow and Left‐Lateral Rupture Event of the 2021 Mw 5.3 Baicheng Earthquake: Implications for the Diffuse Deformation of Southern Tianshan

AbstractOn 24 March 2021, an Mw 5.3 earthquake struck northwest Baicheng, located in the Kuqa fold‐and‐thrust belt (FTB), northwest China. In the current study, interferometric synthetic aperture radar (InSAR) data were used to investigate the associated fault rupture solution (dip, dip direction, and slip sense), to determine the geometry of the seismogenic structure; the high‐resolution images of the surface rupture were obtained using an unmanned aerial vehicle (UAV). This geometric model, along with the co‐seismic slip distribution from the InSAR data, and deformation characteristics of co‐seismic surface rupture revealed that: (a) it was a shallow event, the focal depth was 0.5–2 km, and the co‐seismic slip was distributed in the 0–7 km range with high dip angles (66°, 70°). (b) A 4‐km long surface rupture with obvious left‐lateral strike‐slip was distributed on the surface, and the maximum strike‐slip displacement and width were 0.79 and 0.7 m, respectively. This left‐lateral strike‐slip event indicates that the relative motion between the Tianshan and Tarim blocks is a continuous and diffuse deformation process. The study shows that, when evaluating the earthquake risk of the Kuqa FTB, we should consider both the front position of the fault outburst and the internal compressional salt‐related structures, which can also produce moderate to strong earthquakes.

Drying Grapes after the Application of Different Dipping Solutions: Effects on Hormones, Minerals, Vitamins, and Antioxidant Enzymes in Gök Üzüm (Vitis vinifera L.) Raisins

(1) Background: Raisins contain a wide range of hormones, minerals, vitamins, and antioxidant enzymes that may contribute to the health benefits of consumers. (2) Methods: The aim of this research was to compare the hormone, mineral, vitamin, and antioxidant capacities of Gök Üzüm (Vitis vinifera L.) raisins immersed in oak ash (OA) and potassium carbonate (PC) dipping solutions before drying. (3) Results: Abscisic acid (ABA) (5751.18–11,868.40 ng g−1) and riboflavin (95.17–135.54 mg 100 g−1) were the most abundant hormone and vitamin quantified in Gök Üzüm raisins. Glutathione S-transferase (540.07–744.85 EU gr berry−1), 6-glucose phosphate dehydrogenase (214.50–317.43 EU gr berry−1), and glucose-6-phosphate dehydrogenase (208.25–241.86 EU gr berry−1) enzymes presented the highest antioxidant activity in the samples. Raisins obtained after drying by immersion in OA presented higher indol-3-acetic acid (IAA), ABA, salicylic acid (SA), cytokinins (CK), and zeatin contents; glutathione reductase (GR), glucose-6-phosphate dehydrogenase (G6PD), glutathione S-transferase (GST), 6 glucose phosphate dehydrogenase (6GPD), catalase (CAT), peroxidase (POD), and superoxide dismutase (SOD) enzymatic activity; vitamin B1, B2, B6, C, and A contents; and nitrogen (N), phosphorus (P), manganese (Mn), calcium (Ca), sulfur (S), potassium (K), iron (Fe), sodium (Na), and magnesium (Mg) levels compared to the grapes dried after PC applications. (4) Conclusions: Drying Gök Üzüm grapes after the application of OA dipping solution promotes a higher content of hormones, minerals, vitamins, and antioxidant enzymes compared to PC treatments. These results could help raisin producers to make decisions when using a dipping solution to dry grapes.

Multifunctional AgNW@MXene decorated polymeric textile for highly-efficient electro-/photothermal conversion and triboelectric nanogenerator

In this work, we demonstrate multifunctional and flexible polymeric wearable heaters with highly-efficient electro-/photothermal performance by constructing 3D AgNW@MXene conductive network on the fiber surface, which is realized by a simple alternating solution dip coating technique. The temperature of AgNW@MXene decorated polymeric textile (AM-textile) heater can reach to a high value of 215 ℃ at comparable low voltage (3.5 V), and to 224 °C rapidly within 10 s under a near infrared laser light (100 mW). In addition, a triboelectric nanogenerator using the AM-textile as electrode can transform electrical signal with an open circuit voltage of 62 V through collecting energy from small human movement. Meanwhile, the AM-textile not only maintains the breathability and flexibility of the pristine polymeric textile, but also exhibits excellent antibacterial, flame retardant, and electromagnetic interference shielding ability at the same time, showing great potential for applications in multifunctional wearable heater and self-powered electronic device.

Fabrication of TiO2 nanodot films using simple solution dipping method and block copolymer template

Block copolymer (BCP) self-assembled nanostructures as a template in conjunction with a low-cost inorganic material deposition method can be a practical solution for many applications in the fields of microelectronics, optoelectronics, and plasmonics. Here, we demonstrate the fabrication of TiO2 nanodot films using polystyrene-b-polymethylmethacrylate (PS-b-PMMA) BCP as a template and a simple solution dipping process for TiO2 deposition. For this purpose, we prepared BCP templates using two different methods, namely, the selective deposition method and the masked deposition method. In the selective deposition method, as-grown self-assembled cylinder forming PS-b-PMMA was used as a template and in the masked deposition method, PMMA was etched out selectively from PS-b-PMMA nanostructured films. The scanning electron microscopy results show the average diameter of TiO2 nanodots grown by the selective deposition method is smaller compared to the masked deposition method, whereas the inter-nanodot distance is similar for both deposition methods. X-ray diffraction and photoluminescence confirm the formation of TiO2 in samples deposited by these two methods. The smaller nanodot size for the selective deposition method can be attributed to the limited interaction of the Ti precursor used here with the PMMA copolymer active functional groups. Therefore, in addition to being advantageous due to less processing steps, the selective deposition method can be used for the fabrication of lower dimensional nanostructures by identifying proper precursors and polymers and by controlling the interaction parameters. Our results will be useful for exploring interactions of other polymers with inorganic material precursors and thereby fabricating different nanostructures with desired morphologies using a simple and cost-effective dipping method.

Lipid oxidation and antioxidant delivery systems in muscle food.

Lipid oxidation accelerates quality deterioration in muscle-based foods (fish, red meat, and poultry), resulting in off-odors/flavors, color problems, texture defects, and safety concerns. Adding antioxidants is one approach to control lipid oxidation, and several delivery strategies have been applied, such as supplementing antioxidants to the feed, direct mixing into minces, or, for whole muscle pieces; spraying, glazing, and injection. However, some issues linked to these technologies hinder their wide utilization, such as low effectiveness, noncompatibility with clean label, and off-flavor. These shortcomings have promoted the development of new antioxidant delivery technologies. In this review, the main focus is on the principles, characteristics, and implementation of five novel antioxidant delivery methods in different types of muscle food products. Their advantages and drawbacks are also summarized, plus comments about future trends in this area. Among novel routes to deliver antioxidants to muscle foods are, for whole tissues, recyclable dipping solutions; for minces, encapsulation; and, for both minces and whole tissues, cross-processing with nonmuscle antioxidant-containing raw materials as well as applications of edible films/coatings and active packaging. Advantages of these technologies comprise, for example, low price, the possibility to control the antioxidant release rate, overcoming strong aromas from natural antioxidants, and allowing antioxidant-containing raw materials from the food industry to be valorized, providing an opportunity for more circular food production.

Effects of Some Weak Acids and Moringa oleifera Leaf Extract Powder on the Colour of Dried Apple

This study aimed to find alternatives to sulphite as a preservative for dried fruits. Granny Smith apples were sanitised in a 200 ppm sodium chlorite solution, de-cored, peeled, and cut into slices. The sliced apples were pre-treated/dipped in a water solution containing the three weak acids, namely, ascorbic acid (AA), citric acid (CA), and potassium sorbate (PS) as well as Moringa oleifera leaf extract powder (MOLEP). A screening fractional factorial experiment consisting of five independent variables (AA, CA and PS, time and temperature and MOLEP) constrained at their upper and lower levels (AA: 0.5 to 2.0%, CA: 0.3 to 2.0%, MOLEP: 0.1 to 0.2%, time: 7 to 15 h and temperature: 57 to 70 °C) were evaluated for their effect on the colour of the dried sliced apples. An increase in the concentration of the CA significantly increased the lightness (p = 0.05) and decreased the redness (p = 0.0022) of the dried apple slices. AA and PS did not impact the lightness of the dried sliced apples. A dipping solution of citric acid at 2.0%, Moringa oleifera leaf extract powder at 0.1%, and drying time of 7 h at 70 °C effectively minimized the discolouration of the dried sliced apples.

Quality of fresh-cut apples as affected by dip wash treatments with organic acids and acidic electrolyzed water

The objective of this study was to investigate the effects of dipping in solutions of citric (2%), benzoic (0.2%), sorbic (0.2%) and ascorbic (0.5%) acids and in acidic electrolyzed water on the quality attributes and surface microbiota of fresh-cut apples, cvs ‘Florina’ and ‘Ionathan’, packaged in disposable plastic containers under normal atmospheric conditions during 14 days storage at 8 °C. The colour, firmness, total phenolic content, antioxidant activity and surface microbial load were determined weekly throughout storage. The colour results indicated that acidic electrolyzed water reduced browning while the ascorbic and citric acids were less effective in controlling the enzymatic browning of fresh-cut apples. After 14 days of refrigerated storage, the samples treated with 2% citric acid and acidic electrolyzed water maintained significantly higher firmness, total phenolic content and antioxidant activity than the other treated and control samples. The microbiological analysis revealed that organic acids successfully suppressed bacterial growth throughout the storage period as compared to the control samples. The sorbic and benzoic acids at 0.2% were also effective on yeasts but these dip treatments determined a higher darkening, yellowing and loss of firmness and of antioxidant activity during storage.

Microorganism Profiles of Penile Prosthesis Removed for Infection, Erosion, and Mechanical Malfunction Based on Next-Generation Sequencing

Next-generation sequencing (NGS) is an emerging technology that may allow for more sensitive and sophisticated microbial testing of the microbiota of penile prostheses (PP). To describe the microorganism profiles of PP explanted for infection, erosion, and mechanical malfunction using NGS. All patients who underwent PP removal by two physicians at two institutions were identified. Differences in alpha diversity (ie, number of species detected, species diversity across samples) and microbiome compositional profiles (Bray-Curtis community dissimilarities) across samples were assessed using ANOVA and PERMANOVA, respectively. Number of species detected, species diversity across samples, and microbiome compositional profiles. A total of 83 patients who underwent device removal for infection (n = 8, 10%), erosion (n = 5, 6%), and mechanical malfunction (n = 70, 84%) were included. When considering all devices, 56% (n = 48) of NGS and 29% (n = 24) of standard cultures resulted positive for presence of microorganisms. Culture only detected the most abundant NGS species in 62.5% (n = 5) of infected devices. Species richness and microbiome compositional profiles varied by surgical indication, but not by age, race, diabetes status, or implant duration. Most frequent organisms by surgical indication were Pseudomonas aeruginosa (infection), Staphylococcus epidermidis (erosion), and Escherichia coli (mechanical malfunction). The highest relative abundance organisms were P aeruginosa (infection), Corynebacterium jeikeium (erosion), and E coli (mechanical malfunction). Identifying microbiome profiles of PP removed for infection, erosion, and mechanical malfunction may guide the selection of peri-operative antibiotics and PP antibiotic coatings or hydrophilic dip solutions for each individual scenario. While this is the first study to utilize next-generation sequencing to evaluate penile prosthesis biofilm, the clinical significance of these findings has yet to be determined. A prospective, randomized trial aimed at evaluating the clinical significance of NGS in patients with PP infection is currently underway. NGS testing identified distinct microbiome profiles of PP removed for infection, erosion, and mechanical malfunction.

Mussel-inspired environmentally friendly dipping system for aramid fiber and its interfacial adhesive mechanism with rubber

To strengthen the interfacial adhesion between aramid fiber and rubber, inspired by mussel adhesion protein and mimicking adhesive molecule, a new environmentally friendly dipping system was developed. Specifically, water-soluble pyrogallic acid and polyethyleneimine are reacted to form a network structure, which is then mixed with rubber latex to prepare the dipping solution. We use blocked isocyanate and epoxy aqueous solution to activate the fiber, and then conduct the dipping treatment. The H pull-out force between modified aramid fiber and rubber reached 147 N, achieving the level of traditional resorcinol-formaldehyde-latex dipping system (154 N), while avoiding the utilization of harmful resorcinol and formaldehyde. In addition, we employed atomic force microscope for the first time to quantitatively characterize the modulus of the transition layer between the fiber and rubber. Results from this research provide new insights into the interfacial design of aramid fiber/rubber composites and will facilitate the development of aramid fiber/rubber composites.

A multi-function textile with pH-induced switch wettability transition for controllable oil−water separation

The deterioration of water ecology caused by the discharge of oil spill wastewater, industrial sewage, and municipal sewage has attracted wide attention worldwide. Thus, it is significant to design a simple, environmentally friendly approach to separate oil–water mixtures. In this work, three different fabrics with pH-induced wettability transition were prepared by a dip-coating process for oil and water separation. The dip-coating fabrics had the advantages of oil–water separation, photocatalytic degradation, and recycling. Polyethylene terephthalate/polyamide nonwoven fabric was used as the substrate materials of the fabric. The carboxylic acid-modified TiO2 endowed the fabric with hydrophilicity–hydrophobicity and photocatalytic properties. The Fe3O4 nanoparticles obtained by the coprecipitation method provided magnetism for the fabric, facilitating the recycling of the fabric and improving the hydrophobicity of the fabric. The fabrics coated with dipping solutions were superhydrophobic in a neutral environment and hydrophilic in an alkaline environment. Among the three coated fabrics, the fabric coated with stearic acid/TiO2-Fe3O4 (FST) had the most satisfying oil–water separation performance and durability. Under the neutral condition, the contact angle of the FST was 151° and the separation efficiency was 98%. Under the alkaline condition, the underwater oil contact angle of the FST was 150° and the separation efficiency was 95%. After 15 cycles, the oil–water separation rate of the FST was still higher than 90%. Due to the presence of TiO2, the coated fabric had an exceptional performance in the photodegradation of organic pollutants (69.9%). In addition, the fabrics can be quickly recovered due to magnetism.

MXene-decorated nanofiber film based on layer-by-layer assembly strategy for high-performance electromagnetic interference shielding

With the increase of electromagnetic radiation pollution, there is an urgent need to develop lightweight, ultra-thin, and high electromagnetic shielding composite film to eliminate unwanted electromagnetic interference. Herein, based on the layer-by-layer assembly strategy, a simple solution dip coating method was used to achieve the combination of two-dimensional transition metal (MXene) and nanofiber film, thereby constructing a conductive composite film with a unique undulating structure. The silicon-containing hydrophobic layer imparted excellent hydrophobic properties to the composite film while maintained the stability of the sandwich structure. The contact angle (CA) of the composite film with ultra-thin thickness (29um) was 125.49° and the conductivity was as high as 71.91 S/cm. The hydrophobic treatment would not damage the flexibility and mechanical properties of the composite film. In particular, the average shielding effectiveness (SE) and SSE/t could as high as 28.82 dB and 12422.41 dB cm2g−1, due to the layered structure formed by the connection of countless MXene nanosheets is beneficial to promote multiple absorption and reflection. This layer-by-layer assembly strategy provides a facile route in fabricating light-weight, flexible and ultrathin composite film for high-performance electromagnetic shielding, which is of great significance for broadening the practical application of MXene-based conductive materials.