Improvement Of Hydrophilicity Research Articles

TiO2/AgBr nanocomposite as a novel hydrophilic and photocatalytic modifier in the fabrication of polyethersulfone membrane for wastewater treatment

Enhancing the performance of filtration membranes to improve their antifouling, permeability, and stability is a crucial objective. This can be acquired through the development of innovative materials and methods. With this in mind, the exertion of novel materials is considered a promising approach for modifying polymeric membranes. This study focuses on the potential of incorporating TiO2/AgBr photocatalytic nanocomposites to improve the hydrophilicity, antifouling, and permeability of polyethersulfone (PES) membranes. Following the synthesis of TiO2/AgBr, the study examines its impact on the performance of PES membranes by introducing various concentrations of TiO2/AgBr nanocomposite. Notably, the water contact angle significantly decreases from 68.5° to 44.2°, indicating an improvement in hydrophilicity. This enhanced overall porosity leads to almost a twofold increase in pure water permeability, with the bare membrane registering 78.3 L/m2h.bar and the membrane containing 0.2 wt% TiO2/AgBr achieving 152.4 L/m2h.bar. Due to the photocatalytic activity of TiO2/AgBr, the modified membranes demonstrate promoted antifouling performance, when UV irradiation is used in the washing step of the fouled membranes, as evidenced by the increased flux recovery ratio values, rising from 48 to 60.6 %. The rejection of two different dyes was assessed and the results of 83.9 % and 95.2 % rejection were obtained for Reactive Black 5 (RB5) and Lanasol Red 6G, respectively. Furthermore, the antibacterial activity of TiO2/AgBr was also indicated by confocal microscopy analysis. Thus, embedding TiO2/AgBr not only enhances antifouling properties but also improves the membranes’ ability to reject dyes effectively.

Mesoporous Mg–Al–Ti composite oxide incorporated mixed matrix ultrafiltration membrane with superior multi-heavy metal removal capacity, anti-fouling & anti-microbial property

Mesoporous Mg–Al–Ti ternary composite oxide nano-adsorbents have demonstrated an exceptional performance to remove multiple heavy metals (As, Pb, Cd, Cr). Incorporation of these nanoparticles (NPs) in polysulfone membrane created a multifunctional mixed matrix membrane (MMM) with heavy metal adsorption capacity (both cationic and anionic species), enhanced hydrophilicity, anti-fouling property, and anti-microbial activity. The best heavy metal removal performance was shown by the membrane incorporated with 0.8 wt% NPs. Hydrophilicity improvement was studied through the decrease in water contact angle from 71° to 57° and surface probing using atomic force microscopy (AFM). With a maximum As(III) adsorption capacity of 256.6 mg/g, the membrane had a breakthrough volume of 25L and could provide safe drinking water for 19 h from a real Arsenic (As) contaminated groundwater sample with a flux of 48 l/m2-h. Beyond that, >90 % removal of Cd, Pb & Cr was also observed with maximum adsorption capacity of 652.9 mg/g, 332.5 mg/g, and 89.4 mg/g respectively. 92.5 % flux recovery after filtering a 1000 ppm bovine serum albumin showed the anti-fouling property. Successful inhibition of both gram-positive and gram-negative bacterial growth, and >99.99 % removal of colony forming units (CFU/ml) in the filtration process confirmed the anti-microbial resistance. With its multifunctionality, these membranes hold great potential for practical water treatment applications.

Structural and interfacial microenvironment modulation of two-dimensional layered niobium phosphate to enhance uranium adsorption

To address the environmental and resource challenges arising from the advancement of the nuclear power industry, it becomes imperative to foster the development of efficient and expeditious materials for uranium adsorption. Here, for the first time, a kind of niobium phosphate with improvement of interlayer spacing and hydrophilicity (NbP-8) is employed by crystal phase modulation for uranium adsorption, which synergistically realizes structural and interfacial microenvironment modulation. Characterizations demonstrate that the expanded interlayer spacing contributes to accommodation of uranyl which increases adsorption capacity, and the enhanced hydrophilicity reduces infiltration time and greatly accelerates the adsorption rate. Consequently, NbP-8 possesses exceptional adsorption capacity of 1470.4 mg g−1, ultra-fast adsorption rate with an equilibrium time of 1 min and high selectivity, delivering one of the best phosphate uranium adsorbents. Moreover, this work opens a new venue for optimizing performance of phosphate by changing the crystal phase to modulate structure and interfacial microenvironment for uranium adsorption.

Improvement of hydrophilicity and formation of heparin/chitosan coating inhibits stone formation in ureteral stents

Ureteral stents play an important role in draining urine, supporting the ureter, and preventing hydronephrosis and renal failure. Stones on the surface of ureteral stents can lead to local injury, urinary tract obstruction and tumor induction in patients. They are categorized as normal metabolic stones and infected stones according to whether bacterial infection occurs. To inhibit the formation of ureteral stones, monomethoxy poly(ethylene glycol)-poly(trimethyl carbonate) (mPEG-PTMC) is synthesized to improve the surface hydrophilicity of PTMC/PLCL biodegradable elastomers, and heparin/chitosan coatings are formed by layer-by-layer electrostatic self-assembly. The mPEG-PTMC effectively improves surface hydrophilicity without compromising the compatibility of the components. The contact angle is 62.58° when 10 wt% of mPEG-PTMC37 is present. Extracorporeal immersion for 1, 5, and 10 weeks mimicks normal metabolic stones, SEM and ICP-OES show that the increase of hydrophilicity could reduce the adhesion of calcium oxalate stones. The HEP/CTS coating also significantly reduces the coverage of calcium oxalate on the surface of the sample, and the calcium concentration decreases by 68.5 %. Equipped with an extracorporeal dynamic urinary circulatory system to simulate the production of infected stones after bacterial infection, after seven days, mPEG-PTMC37 halved the stone surface coverage. Compared to PTMC/PLCL elastomer, mPEG-PTMC37, mPEG-PTMC28 and HTP/CTS coatings inhibit 38.72 %, 15.55 %, 39.60 % of Ca and 65.06 %, 57.47 %, 70.11 % of Mg, respectively. In addition, the heparin/chitosan coatings reduce the surface adhesion of Staphylococcus by 69.9 %. The cell experiments show the materials all have good biocompatibility. It makes a useful exploration for developing a new kind of ureteral stents.

Hydrophilic surface modification of polypropylene by AC-DBD and NS-DBD

Dielectric barrier discharge (DBD) is a method to modify material surfaces by creating low-temperature plasma at atmospheric pressure. However, in comparison to low-pressure discharge, atmospheric DBD has the drawback of uneven surface treatment due to the ease of forming filamentary channels. This limitation hinders the widespread application of DBD technology in material surface modification. In this study, the surface of polypropylene (PP) was treated using high frequency alternating current (AC) and nanosecond (NS) pulsed argon DBDs to improve surface hydrophilicity. The changes of the PP surface hydrophilicity and the treatment uniformity were characterized by water contact angle (WCA) measurement. The relationships between the DBD characteristics, the treatment effect and the treatment uniformity of the PP surface were investigated using electrical and optical diagnostic techniques. The PP material surfaces before and after plasma treatments were evaluated by the physical morphology and chemical composition measurements to examine the influence of DBD on the treatment effect and uniformity on the PP material surface. The findings show that the modification by AC-DBD reduces the WCA of PP material surface by 40°∼50° and exhibits a variance of 1.77, indicating an improvement in hydrophilicity to some extent. Furthermore, the modification by NS-DBD further decreases the WCA of PP material surface, reducing the variance to 1.14. Compared with AC-DBD, NS-DBD has a better uniformity, a higher concentration of active particles in plasma, a greater surface roughness of PP material after treatment, a better hydrophilicity and a more uniform effect with less energy consumption. The results are meaningful to improve the application of DBD in material surface modification and optimize the power source election and operation parameters.

Research on coal dust pollution prevention and control based on co-solvent association: Macro-micro experiments and molecular dynamics simulations

In order to better solve the environmental pollution caused by coal dust flying. In this paper, the improvement of wetting and hydrophilicity of coal dust by the binary association solution of surfactant and chelating agent tetrasodium iminodisuccinate (IDS) was studied from the perspective of experiment at the Microcosm–macrocosm analogy levels. To further explore the synergistic mechanism between chelating agents and surfactants, a coal surfactant/chelating agent water three-phase system was constructed using molecular dynamics simulation, and the motion trends of each molecule in different solution systems were analyzed in depth. The combined analysis revealed that sodium dodecylbenzenesulfonate had the best wetting performance when associated with IDS. It increases the surface pores and specific surface area of coal, and the surfactant is more widely adsorbed on the surface of coal dust. The proportion of oxygen-containing hydrophilic groups in coal dust increases, achieving improvement in wetting and hydrophilicity. Overcoming the problem of difficult wetting of coal dust has important practical significance for spray dust reduction and prevention of coal dust pollution.

One-step assembly of bimetal-phenolic networks for antifouling and antibacterial coatings

Titanium (Ti) and its alloys have been widely used as clinical implant biomaterials. However, protein adhesion and bacterial infection can negatively impact the efficacy of these implants. To combat this, a promising strategy is to develop a versatile coating on Ti materials that endows them with antifouling and antibacterial capabilities. This work focused on the development of a polydopamine (PDA) and poly(sulfobetaine methacrylate) (PSBMA) co-deposition coating on Ti substrates. The coating contained copper ions, iron ions, and catechol groups, which coordinated to assemble bimetal-phenolic networks (bMPNs). Digital imaging, SEM, AFM, XPS, water contact angle, and film thickness tests confirmed the success of the modification. The antibacterial properties of the coating were evaluated using Gram-positive Staphylococcus aureus, while the cytotoxicity of the coating on human umbilical vein endothelial cells was also examined. The results demonstrated an excellent improvement in hydrophilicity, antibacterial properties, and benign biocompatibility of the coated Ti substrate, making it suitable for bioimplants and medical devices.

Transparent and Superhydrophilic Flexible Protein Films with Antifogging and Self-Cleaning Attributes.

Cyanoglycoside-modified flexible protein films, exhibiting a high level of transparency of ≈46 to 83%, were successfully prepared from lysozyme and glycerol with varying amounts of amygdalin (20, 40, and 60%) using water as a solvent. The increasing percentage of amygdalin leads to a drastic improvement of the hydrophilicity of the surface with a decrease in the water contact angle to 5.6°, resulting in superhydrophilicity. The increasing percentage of amygdalin led to a significant improvement in the surface's hydrophilicity, resulting in a reduced water contact angle of 5.6° and achieving superhydrophilicity. This superhydrophilic characteristic is particularly relevant to the excellent antifogging and self-cleaning properties of the resulting protein films. In addition to enhanced flexibility, the films also exhibited considerably improved thermal stability with a 40% loading of amygdalin in the protein solution. The superior mechanical, optical, and thermal properties of amygdalin-modified films are due to the strong hydrogen bonding with the peptides of lysozyme, as evidenced by the disappearance of amide bands in the cured protein films. Therefore, these transparent protein films, with their antifogging and enhanced thermal stability properties, can be potentially used for different packaging and coating applications.

Zwitterionic material for construction of an antifouling polyamide thin film composite membrane

Zwitterionic materials containing equal proportions of positively and negatively charged groups have been used to provide membranes with antifouling capabilities. This study focuses on the modification of a commercially available polyamide thin-film composite membrane with a zwitterionic material and investigates its effectiveness in fouling mitigation. The zwitterionic material, sulfobetaine vinylimidazole (SBVI), was synthesized by reacting 1,3-propane sulfone with 1-vinyl imidazole. A NF90 polyamide membrane functionalized with propagyl bromide was modified by the polymerization of SBVI on its surface. Various techniques were used to verify the successful modification of membranes. The water flux and salt rejection of the pristine and modified membranes were measured under comparable stabilization conditions, and showed an increase in salt rejection and a decrease in permeability for the modified membrane because of additional membrane resistance. However, fouling tests conducted with a wide range of foulants in cross-flow filtration mode showed a lower fouling ratio and higher recovery ratio for the modified membrane than for the pristine membrane. The enhancement in the antifouling characteristics of the modified membrane was mainly attributed to the improvement in hydrophilicity resulting from the zwitterionic brushes. Our results demonstrated the fouling resistance is further reinforced in an ionic environment through the “salting-in” effect.

Influences of Four Kinds of Surfactants on Biodegradations of Tar-Rich Coal in the Ordos Basin by Bacillus bicheniformis.

The biodegradation of tar-rich coal in the Ordos Basin was carried out by Bacillus licheniformis (B. licheniformis) under actions of four kinds of surfactants, namely, a biological surfactant (Rh), a nonionic surfactant (Triton X-100), an anionic surfactant (LAS), and a cationic surfactant (DTAB). The biodegradation rates under the actions of Triton X-100, LAS, Rh, DTAB, and the control group (without surfactant) were 59.8%, 54.3%, 51.6%, 17.3%, and 43.5%, respectively. The biodegradation mechanism was studied by examining the influences of surfactants on coal samples, bacteria, and degradation products in the degradation process. The results demonstrated that Rh, Triton X-100, and LAS could promote bacterial growth, while DTAB had the opposite effect. Four surfactants all increased the cell surface hydrophobicity (CSH) of B. licheniformis, and Triton X-100 demonstrated the most significant promotion of CSH. The order of improvement in microbial cell permeability by surfactants was DTAB > TritonX-100 > LAS > Rh > control group. In the presence of four surfactants, Triton X-100 exhibited the best hydrophilicity improvement for oxidized coal. Overall, among the four surfactants, Triton X-100 ranked first in enhancing the CSH of bacteria and the hydrophilicity of oxidized coal and second in improving microbial cell permeability; thus, Triton X-100 was the most suitable surfactant for promoting B. licheniformis's biodegradation of tar-rich coal. The GC-MS showed that, after the action of Triton X-100, the amount of the identified degradation compounds in the toluene extract of the liquid product decreased by 16 compared to the control group, the amount of dichloromethane extract decreased by 6, and the amount of ethyl acetate extract increased by 6. Simultaneously, the contents of alkanes in the extracts of toluene and dichloromethane decreased, lipids increased, and ethyl acetate extract exhibited little change. The FTIR analysis of the coal sample suggested that, under the action of Triton X-100, compared to oxidized coal, the Har/H and A(CH2)/A(CH3) of the remaining coal decreased by 0.07 and 1.38, respectively, indicating that Triton X-100 enhanced the degradation of aromatic and aliphatic structures of oxidized coal. Therefore, adding a suitable surfactant can promote the biodegradation of tar-rich coal and enrich its degradation product.

Study of antifouling and decolorization effect in polyethersulfone membranes improved with dendrimer‐modified metal–organic frameworks

AbstractThe Mil‐125(Ti) metal–organic framework nanoparticles were modified with different compounds i.e. polyamidoamine dendrimer (Mil‐Den), chitosan (Mil‐CS) and Mil‐CS‐Den to prepare functional and hydrophilic nanocomposites. These nanocomposites were characterized and applied for modification of polyethersulfone (PES) membrane by blending them in the dope solutions. The mixed matrix PES membranes were manufactured by the nonsolvent‐induced phase inversion method. The introduction of the nanocomposites into the membrane structure led to positive alterations such as the improvement of hydrophilicity and morphology causing the development of permeability and antifouling properties. The bare PES membrane contact angle was decreased from 60° to 34.5° by adding 0.5 wt% of Mil‐CS‐Den nanocomposite. Applications of novel structures with special absorption in 0.5 wt% of Mil‐CS‐Den membrane, caused an increment of porosity, mean pore size and reduction of surface roughness. The permeability was enhanced from 4.2 to 21.43 L/m2 h bar, while fouling was reduced from 48.5% to 13.5% which indicates the strengthening of the antifouling feature of the hydrophobic PES membrane. Also, the flux recovery ratio was enhanced from 66.7% to 89.3% by blending 0.5 wt% of Mil‐CS‐Den. The modified membranes showed an excellent dye separation performance. The attachment of dendrimer and chitosan to the Mil‐125(Ti) surface increased the efficiency of Mil‐125(Ti) in the modification of the PES membrane. The utilization of nanomaterial features can reduce the limitation of membrane processes and reach desirable outcomes. The results of this work indicate the high potential of the modified MOF for the removal of dye contaminants as well as provide a suitable perspective for water purification with the help of membrane processes.

Fine particles removal of pyrolysis gasification flue gas from rural domestic waste: Laboratory research, molecular dynamics simulation, and applications

Chinese rural domestic waste has increased considerably with the modernization of agriculture and urbanization. Pyrolysis gasification is a common high-temperature waste treatment method. However, this method is usually accompanied by a large amount of particle emission. In this study, a rural domestic waste pyrolysis gasification station in Gansu Province, Northwest China, was selected for research. The particle emission characteristics of this station were analyzed, and the results showed that the original particle removal technologies were inefficient in fine particles. Hence, a new method of fine particle treatment, i.e., Cloud-Air-Purifying (CAP) technology, was explored herein. In CAP, fine particles grow in size via heterogeneous condensation in a supersaturated water vapor environment and are then collected efficiently using a supergravity field. A laboratory-scale pyrolysis gasifier and CAP equipment were built. Moreover, the CAP removal efficiency for particles generated from four typical rural domestic waste categories was studied. The results showed that CAP technology considerably increased the efficiency of fine particle removal. However, the removal efficiency for particles released owing to the incineration of wood was only ∼75%. This was because the tar substances formed during wood pyrolysis were attached to the surface of escaping particles, which led to a decrease in their hydrophilicity and particle condensation growth. To address this issue, the improvement in particle hydrophilicity using different surfactants was studied via molecular dynamic simulations. When the increase in water molecule adsorption, surface polarity, and the solid–liquid interaction energy for different surfactants were compared, alkylphenol ethoxylate (OP10) proved to be the most effective surfactant. Finally, the improved CAP technology combined with OP10 was applied to the on-site pyrolysis gasification flue gas treatment. Long term monitoring of the proposed technology revealed that particle removal efficiency remained >94%, exhibiting excellent fine particle removal. The successful application of the proposed technology demonstrates its potential for further application.

Investigation of physical, mechanical and biological properties of polyhydroxybutyrate-chitosan/graphene oxide nanocomposite scaffolds for bone tissue engineering applications

Mechanical properties appropriate to native tissues, as an essential component in bone tissue engineering scaffolds, plays a significant role in tissue formation. In the current study, Poly-3 hydroxybutyrate-chitosan (PC) scaffolds reinforced with graphene oxide (GO) were made by the electrospinning method. The addition of GO led to a decrease in fibers diameter, an increase in thermal capacity and an improvement in the surface hydrophilicity of nanocomposite scaffolds. A significant increase in the mechanical properties of PC/GO (PCG) nanocomposite scaffolds was achieved due to the inherent strength of GO as well as its uniform dispersion throughout the polymeric matrix owing to hydrogen bonding and polar interactions. Also, lower biological degradation of the scaffolds (~30% in 100 days) due to the presence of GO provides essential mechanical support for bone regeneration. In addition, the bioactivity results showed that GO reinforcement significantly increases the biomineralization on the surface of the scaffolds. Evaluating cell adhesion and proliferation, as well as ALP activity of MG-63 cells on PC and PCG scaffolds indicated the positive effect of GO on scaffolds' biocompatibility. Overall, the improvement of physicochemical, mechanical, and biological properties of GO-reinforced scaffolds shows the potential of PCG nanocomposite scaffolds for bone tissue engineering.

Fabrication and Performance Evaluation of a Cation Exchange Membrane Using Graphene Oxide/Polyethersulfone Composite Nanofibers.

Ion exchange membranes, especially cation exchange membranes (CEMs), are an important component in membrane-based energy generation and storage because of their ability to transport cations via the electrochemical potential gradient while preventing electron transport. However, developing a CEM with low areal resistance, high permselectivity, and stability remains difficult. In this study, electrospun graphene oxide/polyethersulfone (GO/PES) composite nanofibers were prepared with varying concentrations of GO. To fabricate a CEM, the pores of the electrospun GO/PES nanofiber substrates were filled with a Nafion ionomer. The pore-filled PES nanofiber loaded with 1% GO revealed a noticeable improvement in hydrophilicity, structural morphology, and mechanical properties. The 1% GO/PES pore-filled CEM was compared to a Nafion membrane of a varying thickness and without a nanofiber substrate. The CEM with a nanofiber substrate showed permselectivity of 85.75%, toughness of 111 J/m3, and areal resistance of 3.7 Ω cm2, which were 12.8%, 4.3 times, and 4.0 times better, respectively, than those of the Nafion membrane at the same thickness. The development of a reinforced concrete-like GO/PES nanofiber structure containing stretchable ionomer-enhanced membrane surfaces exhibited suitable areal resistance and reduced the thickness of the composite membrane without compromising the mechanical strength, suggesting its potential application as a cation exchange membrane in electrochemical membrane-based systems.

Improvement of persistent hydrophilicity and pore uniformity of polyvinyl chloride ultrafiltration membranes by in-situ crosslinking reaction assisted phase separation

A novel in-situ crosslinking reaction assisted phase separation strategy was proposed for persistent hydrophilization and pore size regulation of polyvinyl chloride (PVC) membranes. In-situ cross-linking between PVC molecular chains was achieved through grafting of 3-aminopropyltrimethoxysilane (APTMS) during the dissolution process and cross-linking reactions between siloxanes in APTMS molecules initiated by the coagulation bath (water). The effect of in-situ crosslinking reaction on the structure, separation and anti-fouling performance of the PVC membranes was studied. Through in-situ crosslinking reaction induced phase separation, the migration and curing of polymer molecular chains in the phase separation process were regulated, which endowed the modified membrane with improved hydrophilicity, higher porosity and narrow pore size distribution. The pure water flux of the obtained membrane increased 3.5 times as much as that of the pure PVC membrane. In addition, the flux recovery rate (FRR) of the obtained membrane was increased by 15.9% and the strength was also increased slightly at the same time. The stability of the membranes was also improved, without chemical agents leaching during filtration, avoiding secondary pollution to our environment.

Zwitterionic Surface Modification of Aldehydated Sulfobetaine Copolymers for the Formation of Bioinert Interfaces

This research successfully developed a zwitterionic copolymer, poly(2-oxoethyl methacrylate-co-sulfobetaine methacrylate) poly(OxMA-co-SBMA), in which the OxMA segments have an aldehyde functional group that can undergo a nucleophilic addition reaction with an amine group to generate a Schiff base. At the same time, SBMA units are employed as antifouling groups. This copolymer is grafted via a graft-to process to the surface of an amine-based substrate to form chemical bonds by dip-coating technology and achieves antifouling properties. The synthesized monomer and copolymers are characterized by Fourier transform infrared (FTIR) spectroscopy and NMR to confirm their chemical structure. Notably, dip-coating technology uses a simple “graft-to” immersion process to achieve nonfouling and antiprotein properties. Compared to the previously reported ″graft-from″ technology, dip-coating has the advantage of a fast and simple procedure and is easy to scale up. The poly(OxMA-co-SBMA) copolymer was grafted onto the amino substrate surface by controlling the dip-coating conditions of different grafting temperatures, grafting time, concentrations of copolymer solution, and copolymer molar ratios. The prepared poly(OxMA-co-SBMA) with an optimum pOxMA/pSBMA molar ratio of 1:4 and a molecular weight of 46.8 kDa exhibited an improvement of hydrophilicity and the best resistance to protein adsorption with over 90% reduction, as well as blood cell activation, tissue cell adhesion, and bacterial attachment on the zwitterionic copolymer-grafted surfaces. The results showed that the modified samples under the best grafting conditions could effectively reduce the biofouling of biomolecules. Meanwhile, it performed well in modified amine-based plastic materials, such as polyurethane tubes and polyamide bending fabrics, which are expected to have broader bioinert application potential in biomedical materials.

PGS/Gelatin Nanocomposite Electrospun Wound Dressing.

Infectious diabetic wounds can result in severe injuries or even death. Biocompatible wound dressings offer one of the best ways to treat these wounds, but creating a dressing with a suitable hydrophilicity and biodegradation rate can be challenging. To address this issue, we used the electrospinning method to create a wound dressing composed of poly(glycerol sebacate) (PGS) and gelatin (Gel). We dissolved the PGS and Gel in acetic acid (75 v/v%) and added EDC/NHS solution as a crosslinking agent. Our measurements revealed that the scaffolds' fiber diameter ranged from 180.2 to 370.6 nm, and all the scaffolds had porosity percentages above 70%, making them suitable for wound healing applications. Additionally, we observed a significant decrease (p < 0.05) in the contact angle from 110.8° ± 4.3° for PGS to 54.9° ± 2.1° for PGS/Gel scaffolds, indicating an improvement in hydrophilicity of the blend scaffold. Furthermore, our cell viability evaluations demonstrated a significant increase (p < 0.05) in cultured cell growth and proliferation on the scaffolds during the culture time. Our findings suggest that the PGS/Gel scaffold has potential for wound healing applications.

Tailoring Black TiO2 Thin Films: Insights from Hollow Cathode Hydrogen Plasma Treatment Duration

In this study, we report the use of a radiofrequency plasma-assisted chemical vapor deposition (RF-CVD) system with a hollow cathode geometry to hydrogenate anatase TiO2 thin films. The goal was to create black TiO2 films with improved light absorption capabilities. The initial TiO2 was developed through magnetron sputtering, and this study specifically investigated the impact of hollow cathode hydrogen plasma (HCHP) treatment duration on the crucial characteristics of the resulting black TiO2 films. The HCHP treatment effectively created in-bandgap states in the TiO2 structure, leading to enhanced light absorption and improved conductivity. Morphological analysis showed a 24% surface area increase after 15 min of treatment. Wettability and surface energy results displayed nonlinear behavior, highlighting the influence of morphology on hydrophilicity improvement. The anatase TiO2 phase remained consistent, as confirmed by diffractograms. Raman analysis revealed structural alterations and induced lattice defects. Treated samples exhibited outstanding photodegradation performance, removing over 45% of methylene blue dye compared to ~25% by the pristine TiO2 film. The study emphasized the significant impact of 15-min hydrogenation on the HCHP treatment. The research provided valuable insights into the role of hydrogenation time using the HCHP treatment route on anatase TiO2 thin films and demonstrated the potential of the produced black TiO2 thin films for photocatalytic applications.

Magnetic‐field‐inducedFe3O4@CNTsdispersion in the separation layer to improve the performance of composite ultrafiltration membrane

AbstractIt is of great significance to regulate carbon nanotubes (CNTs) dispersed in the separation layer of membranes to improve the properties of membranes. In this work, ferric oxides coated carbon nanotubes (Fe3O4@CNTs) are prepared by solvothermal method, and then are added to the casting solution to prepare Fe3O4@CNTs/poly(ethersulfone)/sulfonated polysulfone composite ultrafiltration membranes. The result shows that Fe3O4@CNTs migrate to the separation layer of membranes under the induction of a low‐intensity magnetic field. The surface and overall porosity of the membranes increase and the surface roughness of the membranes decreases. The contact angle of composite ultrafiltration membranes decreases from 78.0° to 60.1°, indicating an improvement of hydrophilicity. The pure water permeance of the composite ultrafiltration membranes increases from 240.1 to 524.7 L m−2 h−1while retaining a high bovine serum albumin rejection (&gt;96.8%). Moreover, the antifouling property of the composite ultrafiltration membranes is significantly improved, and the flux recovery ratio increased from 56.2% to 80.9%.

Inhibition of Coliforms and Escherichia coli Bacterial Strains in Water by 3D Printed CS/GO/AgNP Filtration Membranes

The effect of 3D printed modified Chitosan membranes on bacterial strains by water filtration system was explored in this study. Specifically, it focused on the characterisation of 3D printed Chitosan–graphene oxide–silver nanoparticles (CS–GO–AgNP) composite membranes and the effects of Dimethylacetamide (DMAc) used as co-solvent on the performance of the CS–GO–AgNP nanocomposites. It also examined the impact of GO–AgNP on the CS matrix for inhibition of Fecal Coliforms, Total Coliforms and Escherichia coli (E. coli) bacterial strains in contaminated surface water. The increase in DMAc concentration and subsequent reduction in CS mole fraction within the ink formulation resulted to wider distribution of AgNP across membrane surface, improvement in mechanical strength and surface hydrophilicity of the modified CS membranes. Similarly, increase in GO–AgNP concentration effectively reduced the spread of the identified microorganisms. Sample B-12 with 79% CS, 21% DMAc and 1.2 ml of GO–AgNP exhibited the highest inhibition of the bacterial strains, with more than 95% of Fecal and Total Coliforms suppressed or inactivated, while 99.9% of the E. coli bacterial cells were completely prevented, indicating that our 3D printed modified CS membranes can effectively be used for water treatment.