Nanocomposite Thin Films Research Articles

Exploring the biomedical potential of chitosan‐ceria nanocomposites: synthesis and characterizations

The objective of this study was to synthesize and evaluate the biological effectiveness of cerium oxide (CeO2) against various bacterial and fungal strains. The chitosan‐CeO2 nanocomposite was comprehensively characterized. The Fourier transform infrared (FTIR) spectra displayed a combination of bands that provided evidence for the existence of a composite complex between the chitosan (CS) structure and the Ce–O bands originating from CeO2 nanoparticles. SEM measurements showed uniform dispersion across the whole CS surface, and the morphological changes were clearly observed as the CeO2 nanoparticle content was increased. In contrast, CS‐CeO2 demonstrates enhanced antibacterial efficacy against both Gram‐positive and Gram‐negative pathogens. The MTT method was utilized to assess the cytotoxicity of the examined CS‐CeO2, with the aim of evaluating the cell viability of various cancer cell lines under varying ultraviolet (UV) exposures. The enhanced penetration of CS and CeO2 nanocomposites into cancer cells during their anticancer activity, even in the absence of UV light, led to an increased rate of cell death. The administration of greater dosages of CS and its CeO2 nanocomposites led to an increased generation of reactive oxygen species (ROS), which was observed to be associated with an enhancement in the efficacy of anticancer activity. The impact was additionally amplified through exposure to UV radiation. The nanocomposite thin films demonstrated much higher antioxidant activity against the DPPH radical as compared to ordinary vitamin C. The aforementioned observation was derived from an evaluation of the antioxidant properties of the subject utilizing the DPPH free radical scavenging technique.

Investigations on Impact of YSZ Nanoparticles on Morphology & Electrical conductivity of PEDOT: PSS

Conductive polymer nanocomposites, which combine the flexibility and conductivity of polymers with the unique properties of nanofillers, have generated interest in various fields such as energy storage, sensors, coatings, and corrosion protection. This study discusses the effect of Yttria-stabilized zirconium nanoparticles (YSZ NPs) on the morphology and electrical conductivity of poly(3,4-ethylenedioxythiophene): poly(4-styrenesulfonate) (PEDOT: PSS). Thin films of PEDOT: PSS and PEDOT: PSS: YSZ were fabricated using spin coating technique. FTIR and XRD characterizations confirmed the interaction between YSZ nanoparticles and the PEDOT: PSS matrix, leading to changes in chemical morphology and film crystallinity. The investigation of the current-voltage (I-V) relationship showed improved electrical conductivity in PEDOT: PSS films with the addition of YSZ nanoparticles, with respective conductivities of 0.028×10−6 S cm−1 and 0.0885×10−4 S cm−1 for pristine and YSZ-containing films. Additionally, the sensing properties of the PEDOT: PSS: YSZ film in detecting organic vapours were studied. These findings suggest that these conducting polymer nanocomposite thin films could potentially be used as electrolyte components in battery cells, supercapacitors, and fuel cells, as well as serve as sensors for certain organic vapours.

Spray coating vapor-phase interfacial polymerization: A new approach for developing 2D nanosheet enabled thin film nanocomposite membranes to remove heavy metal ions

Alternate to the conventional dip coating method, a new eco-friendly approach has been used to develop thin-film nanocomposite (TFN) membranes in this research work, all while preserving the exceptional separation capabilities of TFN membranes. The methodology is altered by employing spray coating and implementing vapor-phase interfacial polymerization (VP-IP) to craft thin-film nanocomposite membranes. This innovative approach significantly reduces reagent consumption and eliminates the need for organic solvent (n-hexane). By incorporating amine-functionalized graphene oxide (GO-NH-NH2) as a nanofiller, we have fabricated both thin-film nanocomposite (TFN) and thin-film composite (TFC, without nanofiller) membranes. Developed membranes were characterized with various physicochemical characterization techniques and tested against heavy metal ions. The membranes demonstrated outstanding performance, with ∼ 96 % rejection of Na2SO4, ∼95 % rejection of Pb(NO3)2, ∼94 % rejection of CuSO4, and ∼ 92 % rejection of CdSO4 salt with highest pure water flux 46.57 Lm2h−1. The antifouling characteristics and antibacterial activity of the membrane were also assessed, revealing that including nanosheets has substantially elevated the antifouling properties, notably by increasing the flux recovery ratio. Furthermore, the prepared membranes exhibited enhanced antibacterial performance after incorporating these nanosheets.

Incorporation of Magnetic Filler (Co0.2Zn0.2Cd0.6Fe2O4) in PVA Matrix and Studying the Structural, Optical and Mechanical Properties of Nanocomposite Films

AbstractThe goal of this study is to synthesize nanocomposite PVA/ Co0.2Zn0.2Cd0.6Fe2O4 films with varying contents of Co0.2Zn0.2Cd0.6Fe2O4 nanoparticles (x = 0, 0.2, 0.4, 0.6, 0.8) to improve the structural, optical, and mechanical characteristics of the examined materials. Casting technique is used to prepare PVA/ Co0.2Zn0.2Cd0.6Fe2O4 films. X-ray diffraction, FTIR, UV–Vis spectroscopy, and Vickers Hardness were used to examine the effect of magnetic nanoparticle content on the structural, optical, and mechanical characteristics of PVA nanocomposite films. The refractive index rises from 1.4967 for pure PVA to 7.6511 for PVA + 0.8Co0.2Zn0.2Cd0.6Fe2O4, allowing it to be employed in a variety of applications such as solar cell construction. Because of the presence of ferrite in the glass matrix, the average hardness values enhanced and increased from 90.7 to 114.2 MPa. The stress exponent (n) varies from 1.12 to 3.33, with grain boundary sliding as the deformation mechanism for x = 0, viscous glid for x = 0.2, 0.4, and 0.6, and dislocation climb for x = 0.8 nanocomposite thin films.

Incorporation of dendritic silica nanoparticles for the preparation of high‐performance thin‐film nanocomposite membranes

AbstractThe development of thin‐film nanocomposite (TFN) membranes with high performance is conducive to efficient desalination and wastewater treatment. In this work, dendritic mesoporous silica nanoparticles (DLSiO2) were synthesized by a dual‐templating strategy. Afterward, they were introduced into the aqueous phase to fabricate TFN membranes via in situ interfacial polymerization (IP) reaction. Powerful techniques as scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy, Nano zetasizer‐DLS, x‐ray photoelectron microscopy, electrokinetic analyzer, and contact angle were used in the characterization of dendritic structures and nanocomposite membranes. Results revealed that DLSiO2 with special structural characteristics can effectively regulate the IP process, promoting the enhancement of the crosslinking degree, surface hydrophilicity, and surface negative charge of polyaimde (PA) selective layers. It is also beneficial for constructing extra water channels within the PA selective layer to boost the transport of water molecules. As a consequence, the prepared TFN membrane with 0.3 mg/mL DLSiO2 exhibits optimal separation performance and good pressure resistance, acid–base resistance, and anti‐fouling properties. It also exhibited a water permeability of 4.17 L m−2 h−1 bar−1 (increased by 61.7% compared with thin film composites (TFC) membrane) and a NaCl rejection of 99.0%, which were better than those of TFN membranes prepared by introducing other types of silica in other studies.

Improved performance of polyamide nanofiltration membrane embedded with zeolite beta

In this study, zeolite beta nanoparticles were incorporated into an interfacial polymerization procedure for the fabrication of thin film nanocomposites (TFNs). The successful introduction of zeolite beta into the polyamide (PA) selective layer was confirmed by surface attenuated total reflection infrared spectroscopy (ATR-FTIR), and x-ray photoelectron spectroscopy (XPS). The introduction of porous structured zeolite beta improved the water flux and rejection rate of the TFN membrane compared to the PA thin film composite (TFC) membrane. A quantitative performance coefficient is further proposed in this work, comprehensively considering the flux and rejection rate to evaluate the performance of TFNs. For five salt solutions, we found that the TFN0.3 membrane with 0.3 wt% of zeolite particles had a high coefficient of performance. With the help of zeolite particles, the TFN0.3 membrane achieved a high flux of 92.53 L/(m2·h) under an operating pressure of 5 bar. For ion separation from binary solutions, the TFN0.2 membrane with 0.2 wt% zeolite content was a better choice for a wide range of binary mixtures, which is because the addition of zeolite beta resulted in smaller pore sizes, the strongest zeta potential, and the thickest thickness (scanning electron microscope, SEM determined) of the TFN0.2 membrane. All these factors contribute to the selectivity of the TFN0.2 membrane. Our study provides an efficient and cost-effective method to simultaneously improve the permeability and rejection of nanofiltration membranes, facilitating the development of nanofiltration for water recovery.

Exploiting sulfonated covalent organic frameworks to fabricate long-lasting stability and chlorine-resistant thin-film nanocomposite nanofiltration membrane

Incorporating hydrophilic and charged porous nanofillers to prepare high-performance thin film nanocomposite (TFN) nanofiltration (NF) membranes is an effective method to achieve efficient water treatment. In this study, we synthesize the sulfonated covalent organic framework nanosheets (S-CONs) with higher hydrophilicity and electronegativity by immobilizing sulfonic acid groups (–SO3H) on TpPa-1 nanosheets. The S-CONs are incorporated in the PA layer by interfacial polymerization (IP) reaction. The results indicated that the S-CONs could modulate the hydrophilicity, thickness, and electronegativity of TFN-NF membranes. At the optimal addition of S-CONs (0.006 g), the pure water permeance increases to 8.84 L⋅m−2⋅h−1⋅bar−1\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${\\rm{L}}\\cdot{\\rm{m}}^{-2}\\cdot{\\rm{h}}^{-1}\\cdot{\\rm{bar}}^{-1}$$\\end{document}, which is about 1.75 times than the TFC membrane, with a high Na2SO4 rejection reaching 98.97%. The improvement of the separation performance mainly results from the reduction of PA layer thickness (from ~178.00–198.00 to ~100.00–128.00 nm) and the increase of surface electronegativity (from −20.37 to −44.41 mV at pH = 7.00). More interestingly, the amide bond formed between the S-CONs and TMC improved the chlorine resistance of the membranes. This study reveals the potential of using functionalized 2D CONs as nanofillers to modify TFC membranes for efficient nanofiltration.

Lignosulfonate-Coated ZIF-8 as an Effective Nanofiller to Prepare High-Performance Thin-Film Nanocomposite Forward Osmosis Membrane for Heavy Metal Ions Removal

Lignosulfonate-Coated ZIF-8 as an Effective Nanofiller to Prepare High-Performance Thin-Film Nanocomposite Forward Osmosis Membrane for Heavy Metal Ions Removal

Tannic acid etched ZIF-8 incorporated thin-film nanocomposite nanofiltration membrane with enhanced performance

Incorporating functionalized nanomaterials in the selective layer of conventional polyamide nanofiltration (NF) membrane is a promising strategy for overcoming the trade-off between permeability and selectivity. Highly hydrodispersible TA/ZIF-8 composite nanomaterials were prepared by etching ZIF-8 with tannic acid, and the thin-film nanocomposite (TFN) NF membranes were prepared by introducing TA/ZIF-8 into the interfacial polymerization aqueous phase solution. The nanomaterials and NF membranes' structure, chemical composition, and hydrophilicity were comprehensively characterized. The influence and mechanism of introducing TA/ZIF-8 into the polyamide layer on the separation performance of the TFN membranes were discussed by separating typical mono- and divalent salts. The optimal TFN membrane had a water flux of 26.59 LMH-bar−1 (increased by 86.6% than that of the TFC-blank membrane) with 94.95% rejection of Na2SO4 while having good antifouling performance and stability. Furthermore, the inverse size exclusion phenomenon of chlorine-contained salts was explored through relevant control experiments. This work is valuable for expanding the application of 3D nanomaterials in membrane separation technology and preparing high-performance TFN nanofiltration membranes.

MXene-enhanced sulfonated TFN nanofiltration membranes for improved desalination performance

MXene, a recently identified 2D nanosheet, has drawn interest due to its potential application in the modification of thin film nanocomposite (TFN) membranes for the production of clean water. This study presents the development of MXene-based sulfonated TFN (STFN) nanofiltration membrane for the desalination application and chlorine resistance. A novel amine monomer approach of combination such as 1-(2-aminoethyl)piperazine (APIP) and 2,5-diaminobenzenesulfonic acid (DABSA) was proposed for the interfacial polymerization. The as-prepared MXene displayed a thin-layer nanoflakes-like structure. The surface morphology of the membrane indicated that the MXene bound well on the sulfonated TFN membrane. The hydrophilicity of the membrane was enhanced significantly in the STFN membrane, and the lower contact angle value was decreased up to 24°. The filtration performance showed that the water flux and salt rejection were improved in both sulfonated thin film composite (STFC) and STFN membranes. STFN membranes achieved a higher rejection of >93 % for Na2SO4 and MgSO4. The antifouling and chlorine resistance were also improved in STFC and STFN membranes. This study would be an insight for the development of novel STFN membranes for desalination applications.

Microstructural evolution during the crystallization process of sol-gel derived PbZrO3 nanocomposite thin films

For the application of dielectric materials in energy storage, nanocomposition is one of the effective methods to improve their electric breakdown field strength. In this study, PbZrO3-Al2O3 nanocomposite films were prepared by combined thermal evaporation deposition and a sol–gel method. By changing the annealing time, the crystallization process of PbZrO3 matrix and the formation mechanism of Al2O3 nanoparticles were studied, and the microstructure evolution process of composite films was elucidated. The results indicate that before the final annealing at 700 ℃, Al atoms have diffused into the amorphous PbZrO3 film, and some fine grains of the perovskite phase have been generated at the bottom of the film. As the annealing time increases, the perovskite grains grow along the out of plane direction of the thin film to form columnar grains, and Al atoms diffuse into the perovskite phase lattice; As the annealing time further increases, Al2O3 nanoparticles began to precipitate at the interlayer interfaces of PbZrO3 coating layers, forming a layered distribution. The changes in electric properties with annealing time also demonstrate the microstructural evolution process of the composite film during annealing. Therefore, controlling annealing time is an effective means to control the microstructure and electric properties of composite films prepared by the new method for the application of energy storage.

A novel ZIF-L/PEI thin film nanocomposite membrane for removing perfluoroalkyl substances (PFASs) from water: Enhanced retention and high flux

Membrane separation technology is widely recognized as an effective method for removing perfluoroalkyl substances (PFASs) in water treatment. ZIF-L, a metal-organic framework (MOF) family characterized by its mat-like cavities and leaf-like morphology, has garnered considerable interest and has been extensively employed in fabricating thin-film nanocomposite (TFN) membranes. In this study, a robust, high-performance TFN membrane to remove PFASs in a nanofiltration (NF) process was created through an interfacial polymerization approach on the surface of polysulfone (PSF), incorporating ZIF-L within the selective layer. The TFN membrane modified by adding 5 wt% ZIF-L (relative to the weight of ethylene imine polymer (PEI)) exhibits 2.3 times higher water flux (up to 47.56 L·m−2·h−1·bar−1) than the pristine thin film composite membrane (20.46 L·m−2·h−1·bar−1), and the rejection for typical PFASs were above 95 % (98.47 % for perfluorooctanesulfonic acid (PFOS) and 95.85 % for perfluorooctanoic acid (PFOA)). The effectiveness of the ZIF-L/PEI TFN membrane in retaining representative PFASs was examined under various conditions, including different pressures, feed concentrations, aqueous environments, and salt ions. Notably, the experiments demonstrated that even after contamination with humic acid (HA), >88 % of the water flux could be restored by washing. Additionally, density functional theory (DFT) calculations were employed to predict the distinct intermolecular interactions between PFASs and ZIF-L as well as PEI. These calculations provide additional insights into the interception mechanism of TFN membranes towards PFASs. Based on this study, TFN membranes incorporating MOF as nanofillers show great potential as an effective method for purifying PFASs from aqueous environments and possess superior environmental sustainability and cost-effectiveness.

Boosting Thermoelectric Performance in Nanocrystalline Ternary Skutterudite Thin Films through Metallic CoTe2 Integration.

Metal-semiconductor nanocomposites have emerged as a viable strategy for concurrently tailoring both thermal and electronic transport properties of established thermoelectric materials, ultimately achieving synergistic performance. In this investigation, a series of nanocomposite thin films were synthesized, embedding metallic cobalt telluride (CoTe2) nanophase within the nanocrystalline ternary skutterudite (Co(Ge1.22Sb0.22)Te1.58 or CGST) matrix. Our approach harnessed composition fluctuation-induced phase separation and in situ growth during thermal annealing to seamlessly integrate the metallic phase. The distinctive band structures of both materials have developed an ohmic-type contact characteristic at the interface, which raised carrier density considerably yet negligibly affected the mobility counterpart, leading to a substantial improvement in electrical conductivity. The intricate balance in transport properties is further influenced by the metallic CoTe2 phase's role in diminishing lattice thermal conductivity. The presence of the metallic phase instigates enhanced phonon scattering at the interface boundaries. Consequently, a 2-fold enhancement in the thermoelectric figure of merit (zT ∼ 1.30) is attained with CGST-7 wt. % CoTe2 nanocomposite film at 655 K compared to that of pristine CGST.

Gellan gum-based nanocomposites films containing bio-reduced silver nanoparticles: Synthesis, characterisation and antifungal activity

The aim of this work was to develop and characterise nanocomposite thin films containing silver nanoparticles (AgNPs), as wound dressings and antifungal materials, using a green process for the nanoparticles’ synthesis and a single step procedure for the preparation of the nanocomposite films. To this end, polyphenol-rich extracts obtained from kiwi peels, an agri-food industrial by-product, were used as a reducing agent of silver nitrate salt. The AgNPs were let form within the film-forming solution, which was composed by low acyl gellan gum and a plasticising agent (glycerol or PEG 400 g/mol) and the corresponding nanocomposite films were deposited by the solvent casting technique. The plasticising agent affected the AgNPs distribution within the films, as observed by SEM and EDS analyses, and consequently their tensile behaviour. In specific, AgNPs act as stress intensifiers in the presence of glycerol, whereas they act as film reinforcement with PEG400. However, both glycerol-plasticised and PEG400-plasticised films exhibited similar antifungal efficacy against 16 clinical isolates of 5 different Candida spp (C. albicans, C. lusitaniae, C. haemulonii, C. krusei and C. glabrata). Globally, the present study provides a green and single-step procedure to develop nanocomposite films embedding AgNPs obtained by in situ reduction of silver ions with polyphenol-rich extracts.

Structure and optical characterization of chitosan-chitin/Ag nanocomposite thin films

Chitin and its derivatives are common natural polymers that are widely used in various technological fields. In recent years, considerable attention has been paid to the preparation of polymer nanocomposites based on metal nanoparticles (NPs). Chitin/chitosan-based composites due to high antibacterial activity are suitable for application in related food storage, textile industries. This paper presents an effective and simple method of obtaining chitosan-chitin copolymer/Ag nanocomposites with an extremely high content of metal nanoparticles. The structure and morphology of the synthesized nanocomposites were investigated using X-ray diffractometry, Fourier-transform infrared spectroscopy, electron microscopy, and their optical properties were studied using UV-VIS spectroscopy as well as spectral ellipsometry. It was ascertained that the resulting nanocomposite films are characterized by a uniform distribution of spherical silver nanoparticles, the sizes of which increase (from 55 up to 143 nm) with increasing the Ag+-ions concentration in the reaction mixtures. The optical absorption spectra of nanocomposites are characterized by the presence of an absorption maximum within the range 458…525 nm, which confirms the formation of Ag NPs. A monotonous increase in the values of the energies of optical transitions was observed in the process of increasing the average size of NPs

Innovative enhancement of electron tunneling synergy in carbon-doped Ta2O5[sbnd]CuO photocatalyst with nematic liquid crystal for safe drinking water

This study focuses on enhancing the photocatalytic properties of carbon-doped Ta2O5CuO (C-Ta2O5CuO) nanocomposites for drinking water purification. The nanocomposites were fabricated by depositing C-Ta2O5CuO onto Nematic Liquid Crystal Polaroid (NLCP) obtained from a discarded laptop monitor, employing the sputter deposition method. The X-ray diffraction (XRD) and High-resolution transmission electron microscopy (HRTEM) determined the nanocomposite thin films' crystallinity and structural properties. The EDX and XPS analyses confirmed the elemental composition and reality of the Cu-incorporated Ta2O5 nanocomposites, respectively. The combination of electron tunneling enhancement provided by the NLCP and graphitic carbon led to exceptional photocatalytic performance. This was particularly evident in the efficient degradation of P-Rosaniline Hydrochloride (PRH) dye in an aqueous medium. C-Ta2O5CuO catalytic activities were estimated at various dye concentrations, repeatability, reusability with time, and kinetics. Coating's stability and long-term activity in photocatalysis reactions were also tested. Additionally, Cu present in the C-Ta2O5CuO and ˙OH radicals exhibited remarkable bactericidal activity. They displayed significant antibacterial efficacy against both gram-positive Escherichia coli (E. coli) and gram-negative Staphylococcus aureus (S. aureus) bacteria. These findings have significant implications for the development of advanced materials with potent photocatalytic and antibacterial properties, holding promise for improving drinking water quality and addressing environmental and health challenges.

Improving dye removal ability and fouling resistance of thin‐film nanocomposite nanofiltration membranes using a new citric acid functionalized FSM‐16 mesoporous

AbstractThe development of superior thin‐film nanocomposite (TFN) membranes with good separation performance and anti‐fouling capacity is required to address the larger‐scale freshwater need. In this study, a new citric acid‐functionalized FSM‐16 (CA‐FSM‐16) mesoporous was successfully synthesized and characterized. Subsequently, it was introduced on the surface of the sodium hydroxide/cyanuric chloride‐activated PES membrane to fabricate the CA‐FSM‐16 TFN membrane. It was investigated how various CA‐FSM‐16 loadings affected the overall physicochemical characteristics and performance of the membrane. The SEM analysis confirmed the TFN structure of the fabricated membranes. All manufactured membranes displayed improved hydrophilicity and flux. For the pristine membrane, the salt (Na2SO4) rejection was measured 73.20 ± 2.10%, whereas for the TFN‐0.08 membrane, it was measured 91.40 ± 1.80%. The dye rejection experiment in cross‐flow filtration showed that the TFN‐0.08 membrane had the maximum licorice retention among the membranes (99.10 ± 2.00%). In addition, the CA‐FSM‐16 TFN membranes demonstrated superior antifouling performance, especially the optimum membrane (TFN‐0.08), which showed a high flux recovery ratio (FRR) of 97.10 ± 1.90% and a low irreversible fouling ratio (DRir) of 2.90%. The introduction of CA‐FSM‐16 on the surface of the PES membrane via the surface modification method was a potentially useful technology to fabricate a high‐performing TFN membrane for water treatment applications.

Affinity-based engineering of carbon nanotube embedded polyamide membranes for simultaneous desalination and boron removal

Reverse osmosis (RO) is the leading technology for obtaining drinking and irrigation water from seawater. Although currently developed RO membranes achieve high salt rejection; several challenges exist, such as permselectivity trade-off, biological/chemical contamination, and insufficient retention of small and neutral molecules like boric acid. Due to its toxicity to living organisms and strictly monitored levels in potable water, removal of boron has gained considerable attention in RO industry. Thin film nanocomposite (TFN) membranes have emerged by incorporating nanomaterials with superior water/salt selectivity into polyamide (PA) layer of composite membranes. For the first time, our group investigated the potential of carboxylated carbon nanotube (CNT) embedding in the selective layer of TFN membranes for boron removal. Within this frame, we hypothesize that embedding fillers with low boron affinity accompanied by high water permeability in the selective layer of TFN membranes improves boron removal without suffering from the permselectivity trade-off. In this study, we investigated the boron removal performance of functionalized CNT (f-CNT) embedded TFN membranes. Initially, CNTs were functionalized with three different functional groups (namely, biotin (BIO), 8-amino caprylic acid (ACA), and zwitterion (ZWT)) to narrow down the tube entrance, provide repulsive electrostatic interactions with boron, and interfere with the hydrogen bonding between water and boric acid molecules. Then, TFN membranes incorporating f-CNTs were fabricated, characterized, and tested. Showing high compatibility with PA, ZWT functionalization has increased water/boron selectivity of TFN membranes by 66% and water permeability by 44%, while maintaining the salt rejection at 98%. Furthermore, we employed molecular dynamics simulations and potential of mean force calculations to elucidate the boron exclusion mechanism in f-CNTs. With its flexible structure and “gate-keeper” ability, ZWT functional group was found to show the highest energy barrier against boron transport. Hence, engineering CNT/PA TFN membranes to promote steric hindrance and decrease solute affinity is promising for efficient removal of detrimental small molecules from seawater.

Preparation and characterization of ZnO/CuO nanocomposites thin films for highly efficient visible-light photocatalysis of acriflavine dye

Chemical bath deposition (CBD) was used to grow ZnO nanorods on glass substrates. Grown ZnO nanorods are dipped in a copper nitrate trihydrate [Cu(NO3)2.3 H2O] solution at 90 °C for 30 min before being annealed at 400 °C for 1 h to convert Cu2+ ions to CuO nanoparticles, forming a ZnO/CuO thin films nanocomposite. Images obtained from a Field Emission Scanning Electron Microscope (FESEM) indicated that the ZnO structure consisted of nanorods coated in CuO nanoparticles. The optical absorption of both ZnO NRs and ZnO/CuO nanocomposites thin films was strongly edged, with an energy gap of 3.26 and 3.21 eV, respectively. The photodegradation rate of the manufactured ZnO NRs and ZnO/CuO nanocomposites thin films against Acriflavin dye was investigated at room temperature under varying pH conditions and period exposure to visible light. The rate of photodegradation of the dye was increased by increasing the time it was exposed to light and/or the pH of the solution. The photodegradation rates for AFN dye under visible light irradiation ranged from 36% to 100% as the pH value was increased from 4 to 10, and from 78% to 66% at a pH value of 12 and reduced to 78% at a pH value of 12 after 330 min of irradiation. Furthermore, the trapping experiments of reactive species for Acriflavin dye degradation by ZnO/CuO nanocomposites photocatalysts were also carried out

In-situ interfacial polymerization of polyamide TFN membranes by adding a diamino-silane coupling agent: Toward enhanced desalination performance

The primary challenge faced by thin film nanocomposite (TFN) membrane in nanofiltration (NF) process is to effectively resolve the trade-off effect between permeability and selectivity. Herein, a polyamide (PA) TFN membrane with enhanced NF performance was prepared through in-situ interfacial polymerization (in-situ IP) method, using piperazine (PIP) and 3-diamino-methyl-cyclohexyl triethoxysilane (DTES) as co-amine monomers to undergo a reaction with 1,3,5-benzenetricarbonyl trichloride (TMC). This study investigated the effects of DTES on the surface chemical composition, morphologies, hydrophilicity, separation efficiency, and anti-fouling properties of the novel DTES/PIP/TMC TFN membranes. It was found that SiO2 nanoparticles were generated in-situ from the reacted DTES through hydrolysis and self-condensation, resulting in their uniform distribution within the formed PA selective layer with high compatibility and without aggregation. The optimal PA TFN membrane was achieved by adjusting the ration of Si-OH group in formed SiO2 nanoparticles through varying the concentration of DTES concentration. Meanwhile, the induction of SiO2 into the PA layer resulted in an enlargement in membrane pore size and improved surface hydrophilicity. When the concentration of added DTES was 0.333 wt%, the optimal PA TFN membrane (TFN-4) exhibited the highest quantity of formed Si-OH groups, resulting in the excellent performance, including a markedly enhanced water permeability flux of 76.8 L·m−2·h−1 (2-fold larger than that of the pure TFC membrane), a great Na2SO4 rejection of 97.5 %, and a superior Cl−/SO42− permeation selectivity of 46.0. Moreover, the TFN-4 membrane exhibited exceptional stability and superior antifouling properties attributed to its unparalleled hydrophilicity. This work provided a strategy for preparing uniform and high-performance TFN membranes.