Phase Inversion Method Research Articles

Nanocellulose in Polyvinylidene Fluoride (PVDF) Membranes: Assessing Reinforcement Impact and Modelling Techniques

In this study, polyvinylidene fluoride (PVDF)-based nanocomposite membranes reinforced with cellulose nanocrystals (CNC) and cellulose nanofibrils (CNF) were fabricated using the phase inversion method. The effects of 0.5wt% and 1wt% CNC and CNF on structural, mechanical, and filtration properties were examined. Membranes reinforced with 1wt% CNF exhibited the highest distilled water flux, increasing from 445.91 to 476.17L/m².h, and showed improved antifouling ability and higher total organic carbon (TOC) removal compared to unreinforced membranes. Mechanical properties were modelled using five numerical methods, with finite element and Mori-Tanaka models showing the best agreement with experimental data. Modelling results indicated that finite element and Mori-Tanaka methods were the most accurate in predicting the modulus of elasticity. The reinforcement significantly enhanced the membranes' performance in terms of flux recovery, fouling resistance, and mechanical strength, making this a novel interdisciplinary investigation of nanocomposite membranes focusing on both mechanical and filtration capabilities.

A novel PVDF film containing g-C3N4@MOF composite for efficient photoreduction of Cr(VI) under visible light

In this study, g-C3N4 was successfully synthesized and combined with MIL-88A to form a composite material (g-C3N4@MIL-88A composite, abbreviated as CNM). With the aid of the phase inversion method, CNM-PVDF composite films were synthesized, integrating various functional components. The CNM Z-scheme heterojunction efficiently harvests visible light, enhances interfacial separation, and suppresses the recombination of photogenerated charge carriers, resulting in significant photoreduction of Cr(VI) (94.01%). However, CNM composites in powder form tend to aggregate without stable support, complicating separation and recycling processes. To address this issue, PVDF is used to immobilize the photocatalyst. The results demonstrate that CNM-PVDF films exhibit superior photocatalytic reduction activity towards Cr(VI), achieving an efficiency of 90.4% under optimal conditions: 20 mg/L of Cr(VI), 3% CNM-PVDF, pH 3, and 180 min of irradiation. This study represents a significant advancement in developing and applying composite films, offering excellent photocatalytic performance. Unlike the powder sample (CNM), the CNM-PVDF composite can be easily recovered for four consecutive cycles, effectively overcoming the challenge of secondary pollution.

Erratum: Synthesis and Characterisation of Cellulose Acetate/Polyethylene Glycol Membrane from Pineapple Hump by Phase Inversion Method

Erratum: Synthesis and Characterisation of Cellulose Acetate/Polyethylene Glycol Membrane from Pineapple Hump by Phase Inversion Method

A Novel Sensor Based on Polysulfone/Iron Complex Membranes for Detection of Arsenic Ions in Aqueous Solutions Using the Quartz Crystal Microbalance Method

ABSTRACT Fabricating composite membranes with enhanced permeance and desirable properties for treating aqueous solutions is an effective approach to developing advancing membrane technology. In this study, a sensor membrane was prepared for the sorption and detection of As(III) ions in aqueous solutions. A novel membrane based on polysulfone (PSF) with varying concentrations of iron complexes was prepared using the phase inversion method. The composite membranes were analyzed using FTIR, SEM, XRD, AFM, and TGA. The structures of the membranes exhibited good dispersibility and compatibility with the complexes within the PSF matrix. TGA analysis showed that the thermal stability of the membranes was significantly improved compared to that of pure PSF. The membranes were evaluated as sensors for detecting extremely low concentrations of As(III) ions in aqueous solutions using the quartz crystal microbalance technique. The results indicate that the composite membrane sensors could detect small amounts of As(III) ions in aqueous solutions at different temperatures. Notably, PSF/TBPFe5 at 45°C demonstrated superior sensitivity for As ion detection. Therefore, these membranes are ideal materials for assessing water quality.

Thymoquinone loaded nanoemulgel in streptozotocin induced diabetic wound.

Aim: To treat diabetic wound healing with a novel Thymoquinone (TQ) loaded nanoformulation by using combination of essentials oils.Methods: TQ nanoemulsion (NE) was developed with seabuckthorn & lavender essential oils by phase inversion method and mixture design. Further, DIAGEL is obtained by incorporating NE into 1% carbopol®934. Furthermore, particle size, polydispersity index, thermodynamic stability studies, rheology, spreadability, drug content, in-vitro drug release, ex-vivo permeation, anti-oxidant assay, antimicrobial studies, angioirritance, HAT-CAM assay, in-vitro and in-vivo studies were determined.Results: NE has a particle size of 17.79±0.61nm, 0.206±0.012 PDI & found to be thermodynamically stable. DIAGEL exhibited pseudoplastic behavior, sustained drug release, better permeation of TQ and a drug content of 98.54±0.08%. DIAGEL stored for 6months at room temperature and 2-8°C showed no degradation. Further, an improved angiogenesis, absence of angio-irritancy, remarkable antioxidant and antimicrobial activities against Candida albicans & S. aureus were observed. Cytotoxicity analysis revealed nearly 2.28 -folds higherIC50 value than drug solution. Furthermore, inflammatory mediators were reduced in DIAGEL treated animal groups. The histopathological studies confirmed skin healing with regeneration and granulation of tissue.Conclusion: The novel formulation has strong anti-inflammatory, angiogenesis, antioxidant and appreciable diabetic wound healing properties.

The Influence of Activated Carbon Particle Size on the Properties and Performance of Polysulfone Composite Membrane for Protein Separation

The superiorities provided by polymeric composite membranes in comparison to the original membrane have generated increased attention, particularly in the field of protein separation applications. This work involved the fabrication of polysulfone composite membranes using variable loadings of activated carbon particle sizes, namely, 37 µm, 74 µm, 149 µm, and 297 µm. The membranes were fabricated via the phase-inversion method, employing water as the coagulant. In this study, the impact of the AC powder particle sizes on membrane morphology, water contact angle, porosity, average pore size, molecular weight cutoff, pure water flux, and protein rejection was examined. Different membrane morphologies and properties were achieved by incorporating a variety of AC particle sizes. A porous membrane with the maximum pure water flux was generated by the loading of finer AC particles. Concurrently, protein rejection is increasing as a result of the use of AC particles as an infill in the composite membrane. In comparison to all fabricated membranes, the AC filler with a particle size of 149 µm exhibited the highest rejection of the lysozyme protein, reaching up to 73.9%, with a relatively high water permeability of 33 LMH/Bar. In conclusion, this investigation provides recommendations for the selection of AC particle sizes for protein separation in conjunction with PSF ultrafiltration membranes.

Study of the Adsorption of Eriochrome Black T on Charged Macrospheres Based on Polyglycidyl Methacrylate-Graft-Polyvinyl Chloride

The efficient removal of pollutants from aqueous systems remains a significant challenge in environmental science and engineering, particularly when dealing with hazardous dyes commonly found in industrial wastewater. Our research described in this paper investigated the adsorption of the dye, Eriochrome Black T (EBT), a synthetic azo dye widely used in various industries, onto charged macrospheres based on polyglycidyl methacrylate-graft-polyvinyl chloride (P1). The macrospheres were prepared using the synthesized graft copolymer P1 by the phase inversion method and functionalized by quaternary hydrazine to introduce charged groups on the surface of these macrospheres, enhancing their affinity for the anionic EBT dye. The effects of initial dye concentration, contact time and temperature on the adsorption process were evaluated. Furthermore, adsorption isotherms and kinetic models were applied to elucidate the mechanism of this adsorption process. The results demonstrated that the experimental data of the adsorption process was well-fitted by the Langmuir model isotherm and the charged macrospheres exhibited excellent adsorption capacity for EBT. In the thermodynamic study the adsorption process was found to be exothermic and spontaneous at room temperature. Besides, the kinetics study revealed that the adsorption process was better described by the pseudo-second-order model (R2= 0.992) than the pseudo-first-order model (R2= 0.963), suggesting that chemisorption was the adsorption process. The mechanism of this adsorption was mainly based on electrostatic interactions and hydrogen bonding between the adsorbent and the adsorbate.

Optimization and reusability of photocatalytic g-C3N4/W-TiO2/PVDF membranes for degradation of sulfamethazine.

Pharmaceuticals and personal care products (PPCPs) are prevalent emerging pollutants in the aquatic environment. The photocatalysis process has proven high efficiency in degrading PPCPs; however, the fate and repercussions of photocatalyst residuals are a major concern. To avoid that, we developed a composite from graphitic carbon nitride/tungsten doped with titanium dioxide (g-C3N4/W-TiO2) and loaded it on polyvinylidene fluoride (PVDF) membranes by the phase-inversion method. X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), and other different analyses implied the successful synthesis of g-C3N4/W-TiO2 composite and coating on PVDF membranes. A Box-Behnken design (BBD) was used to optimize the operational parameters, including pH, g-C3N4 ratio in the composite, and initial SMZ concentration by the response surface methodology (RSM). The highest SMZ degradation percentage was 98.60% after 240min of irradiation. Liquid chromatography with tandem mass spectrometry (LC-MS/MS) along with suspect screening was used to identify the intermediate transformation products and propose the SMZ degradation pathway. The loss in membrane activity after five cycles of photocatalytic degradation was about 18%. According to the current study, the photocatalytic membrane g-C3N4/W-TiO2/PVDF is promising for removing sulfonamide antibiotics from wastewater.

Structure-performance relationship in tailored poly(amide-sulfone) membranes for desalination

Poly(amide-sulfone)s were considered the missing link for water desalination membranes, owing to their exceptional properties resulting from the synergism effects of two amide and sulfone structures. To achieve this, a sulfone-based diamine was first synthesized by reacting 4,4′-dichlorodiphenyl sulfone with 3-aminophenol. Subsequently, alternative copolymers of poly(amide-sulfone) were prepared via polycondensation reactions of the synthesized diamine monomer and various diacid chlorides including adipoyl dichloride, isophthaloyl dichloride, and terephthaloyl dichloride. The chemical structures were approved using Fourier transform infrared spectroscopy and hydrogen nuclear magnetic resonance spectroscopy. Porous membranes of the polymers as substrates were prepared by solution casting and phase-inversion method. To form thin film composite membranes, a thin polyamide layer was created through interfacial polymerization on the top surface of prepared substrates using m-phenylenediamine and trimesoyl chloride. After characterization, the performance of all membranes was assessed by evaluating pure water flux, NaCl rejection, and flux recovery ratio using a cross-flow filtration system. The impact of the amide group within the poly(amide-sulfone) substrate structure on thin-film efficiency was explored. Results, revealed that the structure significantly influenced membrane performance. Specifically, the highest pure water flux was 549.50 L.m−2.h−1. Also, NaCl rejection of 98.27 % and flux recovery ratio of 94.21 % were observed among them at pressure of 10 bar. This study provided valuable insights for developing novel poly(amide-sulfone) membranes tailored for desalination applications.

Controlled Distribution of MXene on the Pore Walls of Polyarylene Ether Nitrile Porous Films for Absorption-Dominated Electromagnetic Interference Shielding Materials.

With the increasing application of electronic devices, absorption-dominated electromagnetic interference shielding materials (EMISM) have garnered significant attention for preventing secondary electromagnetic pollution. In this study, polyethyleneimine (PEI)-modified MXene (PEI@MXene) is fabricated and achieved its controlled distribution on the pore walls of polyarylene ether nitrile (PEN) porous films via the phase inversion method (PIM) to obtain a closed porous skeleton of MXene on the pore walls (CPS-MPW). The resulting PEI@MXene/PEN composite film (CFx) exhibited absorption-dominated EMIS efficiency (EMISE). Attributing to the strong interaction between PEI and the hydrophilic segment of amphiphilic Pluronic F127, with its hydrophobic segment anchored by the PEN matrix, PEI@MXene is directionally distributed on the pore walls of CFx. In addition, resulting from the cladding of MXene with PEI and isolating it with closed honeycomb pores, the obtained CFx are insulators without forming aconductive network. As a result, these CFx demonstrate absorption-dominated EMISE with the highest SET of 41.2 dB and coefficient A higher than 0.51. Further continuous hot pressing of CFx results in thinner and denser films with an impressive specific EMISE up to 750 dBcm-1. The successful fabrication of these CPS-MPW-type CFx with absorption-dominated EMISE provides a reference for developing and preparing novel EMISM.

Silicon dioxide incorporated cellulose acetate-mixed matrix membranes for Safranin-O removal from aqueous solutions.

Nanoparticle incorporated-mixed matrix membranes are renowned for their multifaceted advantages, including improved hydrophilicity, elevated solute rejection, enhanced mechanical robustness, and augmented chemical and thermal stability. The inherent hydrophilicity of silicon dioxide (SiO2) nanoparticles, due to silanol groups (Si-OH), along with their high porosity and surface area, renders them an ideal reinforcing filler within polymer matrices, significantly strengthening structural integrity of membranes. In this work, SiO2 nanoparticles were incorporated in a cellulose acetate (CA) matrix to prepare CA/SiO2 adsorptive membranes using phase inversion method. The performance of the membranes was assessed on the removal of Safranin-O (Sf-O) from aqueous solution. The physicochemical characterization of the synthesized membranes was assessed using contact angle, XRD, FE-SEM, EDS, FTIR, TGA, and tensile strength studies. The optimization studies on novel CA/SiO2 membrane revealed that the membrane with 2.5 wt.% of SiO2 in the CA matrix was the best in terms of Sf-O removal (approximately 100% dye removal) when the operating pH, initial dye concentration, and operating pressure were 9, 50 ppm, and 1 bar respectively. It is also found that 2.5 wt.% CA/SiO2 membrane has higher water permeability than other membranes. Incorporating SiO2 nanoparticles into a polymer matrix augments the structural, mechanical, and thermal properties of the resulting membranes while also enhancing water permeability, selectivity, and dye removal efficacy.

An efficient approach in water desalination using high flux induced magnetic-field hydroxyl-functionalized MgFe2O4 /CA RO membranes with organic/inorganic fouling control capability

Reverse osmosis (RO) membranes are crucial for water purification and desalination, facing challenges like balancing permeate flux and rejection, dealing with membrane fouling, and chlorine resistance. This study focuses on developing new membranes using cellulose acetate (CA) polymers and magnetic nanoparticles of magnesium ferrite (MgFe2O4) and hydroxyl-functionalized magnesium ferrite (OH–MgFe2O4) through a phase inversion method, with and without the presence of a magnetic field, to address the limitations of RO membranes. This study conducted a unique experiment where magnetic nanoparticles migrated to the membrane surface and underwent phase exchange in the coagulation bath under the influence of a 2.0 T magnetic field. As a result, the magnetic nanoparticles were arranged in a specific pattern and evenly spread across the membrane surface, enhancing the membrane's surface characteristics and hydrophilic properties. Furthermore, the flux of the synthesized membranes experienced an increase when exposed to the magnetic field, while maintaining a consistently high rejection rate. An evaluation was conducted on the membranes' resistance to organic fouling from bovine serum albumin (BSA), inorganic fouling from scaling, and the combined effects of BSA and scaling. Based on the findings, the membranes showed a notable enhancement in their anti-fouling properties, particularly when exposed to a magnetic field. An assessment was conducted on the resistance to chlorine for both the standard and improved membranes. Comparing the flux and rejection of the membranes before and after chlorine exposure revealed a minor variation, suggesting the membrane's ability to resist surface damage from chlorine. Hence, through the creation of innovative MgFe2O4/CA and OH–MgFe2O4/CA membranes, the identified constraints of RO membranes were effectively addressed. One of the synthesized RO membranes, OH–MgFe2O4/CA, demonstrated superior performance in permeate flux, rejection, anti-fouling, and chlorine resistance when compared to MgFe2O4/CA membranes. Furthermore, the stability of the synthesized membranes was assessed through tensile strength testing, which confirmed the preservation of the membrane structure.

Effect of Polyethylene Glycol Concentration on the Structural and Mechanical Properties of Polysulfone-Based Membranes

Water pollution in Indonesia is a growing concern, necessitating the development of advanced treatment technologies. Membrane-based filtration, a promising approach due to its low energy consumption and ability to preserve material properties, has been explored. Polysulfone (PSf), a commonly used membrane material, is known for its thermal stability, chemical resistance, and mechanical strength. However, its hydrophobic nature limits its filtration performance. To enhance hydrophilicity and porosity, polyethylene glycol (PEG) is introduced as a hydrophilic additive. This study investigated the synthesis of PSf/PEG composite membranes with varying PEG concentrations (0%, 9%, and 14%) using the phase inversion method. Characterization of the membranes revealed that increasing PEG content led to thinner membranes with higher porosity, density, and swelling capacity. While Membrane-A (100% PSf) exhibited the highest tensile strength, Membrane-B (9% PEG) demonstrated the greatest elongation. SEM analysis confirmed that higher PEG concentrations resulted in larger and more numerous pores, forming asymmetric structures suitable for filtration. FTIR analysis verified the successful integration of PEG into the PSf matrix. The findings highlight the potential of PEG-modified PSf membranes for industrial wastewater treatment. The M-C membrane, containing 14% PEG, exhibited the highest swelling degree, indicating improved hydrophilicity and permeability. However, increased PEG content also led to decreased tensile strength. The optimized M-C membrane, with a density of 0.9906 g/cm³, a mass of 1.9249 g, and a thickness of 102 µm, meets the requirements for effective water treatment applications. This research contributes to the development of sustainable membrane technologies for environmental management in Indonesia. By addressing the limitations of PSf membranes, PSf/PEG composite membranes offer a promising solution to water pollution challenges in the region.

Waterborne novolac epoxy‐based thermal resistant and fire‐retardant thermal insulation coatings

AbstractWaterborne novolac epoxy based thermal resistant and fire‐retardant thermal insulation coatings were developed in this work. Novolac (phenolic) epoxy emulsion (PEE) was prepared by the phase inversion method based on formulation optimization by orthogonal array testing. The prepared emulsions have similar particle size, viscosity, and stability to commercial bisphenol a glycidyl ether epoxy emulsion (PZ). DSC results showed that the varnish film based on PEE had a higher glass transition temperature and initial thermal decomposition temperature compared with PZ cured by the same curing agent. Waterborne thermal insulation coating with PEE and PZ as binders and hollow glass microspheres (HGMs) as thermal insulation fillers were studied. The results indicated that the thermal conductivity of the coating decreased with an increase in HGMs content. Specifically, the thermal conductivity of the PEE coating containing 20 wt% HGMs is as low as 0.093 W/(m·K). It reduces the exterior temperature of the hot tank from approximately 200 °C to approximately 106 °C. Furthermore, the HGMs/PEE waterborne thermal insulation coating exhibits good thermal stability and flame retardance.

Preparation and characterization of waterborne silicone modified epoxy resin

AbstractSilicone modified epoxy resin was synthesized with bisphenol‐A epoxy resin (E51) and dimethyldichlorosilane (DMDCS), and waterborne silicone modified epoxy resin (WSER) was prepared. The WSER emulsion exhibited good stability with particle size ranging from 0.5 to 2 μm. Compared with waterborne epoxy resin (WER) cured film, the water resistance of WSER cured film was enhanced by the excellent hydrophobicity of DMDCS. Furthermore, the WSER cured film with 6% DMDCS showed better mechanical properties, and Shore hardness and tensile strength of that were greatly increased. Moreover, the corrosion resistance and ultraviolet (UV) aging resistance of WSER cured film were obviously improved compared to WER cured film.Highlights Dimethyldichlorosilane (DMDCS) was employed to modify bisphenol‐A epoxy resin (E51). Waterborne silicone modified epoxy resin (WSER) was prepared by phase inversion method. WSER cured films did better than WER cured film in water resistance and mechanical properties. WSER cured films showed good corrosion resistance and ultraviolet aging resistance.

Removal of emerging organic micropollutants from real hospital wastewater by modified ultrafiltration membranes

Membrane biofouling, characterized by the adherence and growth of microorganisms on the surface of a membrane, poses a significant challenge to the effectiveness of membrane bioreactor (MBR) technology. Enhancing anti-biofouling characteristics, particularly the prevention of bacterial adhesion to the membrane, is crucial for the sustained operation of MBR over the long term. One of the most popular methods for enhancing these characteristics is surface modification. In this study, two distinct concentrations of 150 µM and 300 µM of BisBAL −a chelate derived from bismuth with strong antibacterial action on a variety of microorganisms- were added to polymeric membrane solutions. Using these solutions, flat sheet (FS) and hollow fiber (HF) membranes were produced via the phase inversion method to examine their removal capabilities for micropollutants in a real hospital wastewater. Caffeine (CAF), Paracetamol (APAP) and Ciprofloxacin (CPFX) were observed as target micropollutants during a pilot-scale MBR operation. The chemical modification of the membranes enhanced the characteristics of the membrane material. Pure water flux values increased while contact angles were decreased in modified membranes When compared to bare membranes, BisBAL-added modified membranes were observed to reject CAF, APAP and CPFX more effectively. When 150 and 300 µM BisBAL is added to FS and HF membranes, the rejection efficiencies of CAF and APAP reached their maximums, exceeding 80 %. Remarkably, CPFX rejection in the case of FS membranes added with 300 µM reached about 30 %, whereas it surpasses 80 % in the case of HF membranes added with the same concentration. The mechanism behind the rejection of micropollutants by the membranes was determined to be adsorption. In addition to their enhanced resistance to biofouling, the new potential of these modified membranes was also demonstrated. The results suggested that membranes modified with 300 µM BisBAL were particularly optimal for the pilot-scale MBR operations in the future, with HF membranes generally outperforming FS membranes.

Polysulfone (Psf) Mixed Matrix Membrane incorporating Titanium Dioxide (TiO2)/Polyethylene Glycol (PEG) for the removal of copper

The global increasing contamination of water resources with toxic metals such as copper (Cu), poses severe threats to human health and aqueous ecosystems. Therefore, the ultrafiltration mixed matrix membranes (UF MMMs) possess an applicable approach for the removal of copper ions. This novel fabricated technology can be applied in various wastewater treatment systems for the removal of heavy metals, especially copper. MMMs were fabricated by blending polysulfone (Psf) with additives into the dope solution via the phase inversion method by incorporating titanium dioxide (TiO2) and polyethylene glycol (PEG) in Psf MMMs. Seven Psf MMMs samples labelled M0 to M6, each with its own formulation, were prepared and tested for density, porosity, and degree of Cu retention. MMMs were further characterized via Fourier transform infrared spectroscopy (FTIR), which revealed the range of the IR spectrum of Psf polymer membrane from 1319 cm-1 to 1600 cm-1, 1650 cm-1 to 3400 cm-1 for PEG, and 800 cm-1 to 3600 cm-1 for TiO2 NPs. As for the scanning electron microscopy (SEM), M6 (Psf/TiO2/PEG 6000) was found to be the most dense and highest porous morphology asymmetric Psf MMM. The retained percentage of Cu and flux for M6 attained the highest value of 80.3% and 136.99 L/m2 .h respectively, whereas for the neat Psf membrane, M0 exhibited the lowest retained percentage of Cu and flux, about 25.8% and 61.64 L/m2.h. The inclusion of pore former and additives has shown an improvement of 54.5% in the copper rejection. Moreover, M6 displayed the highest antifouling properties compared to other Psf MMMSs. This study proves that PEG and TiO2 additives have significant potential to improve membrane performance due to the highest percentage of Cu retained on the surface of the membrane as adsorptive separation on Psf MMMs.

Synthesis and Characterisation of Cellulose Acetate/Polyethylene Glycol Membrane from Pineapple Hump by Phase Inversion Method

Cellulose is a natural polymer contained in growing fibres, such as pineapple fibres. Cellulose can be modified into cellulose acetate, a modified polymer that can be used in the synthesis of a cellulose acetate/polyethylene glycol (CA/PEG) membrane. The phase inversion method was used in this study to produce CA/PEG membranes. Variations in polyethylene glycol (PEG) concentration with a ratio of 1:1 to cellulose acetate, where variations in PEG concentrations used are 2%, 5% and 8%. Acetone and dimethylformamide are used as organic solvents. Membrane morphological analysis using scanning electron microscopy (SEM) and functional group analysis using a Fourier transform infrared (FTIR) spectrometer were performed for membrane characterisation. The result of the synthesis of the CA/PEG membrane is in the form of a thin white layer. The characterisation results of the FTIR spectrometer showed the vibration of the carbonyl bond at wavenumber 1729 cm−1 and the vibration of the hydroxyl bond torque at the wave number 648 cm−1, where the vibration intensity decreased with each addition to the concentration. The results of SEM characterisation show that the increase in PEG concentration increases the percentage porosity of the membrane. The membranes with 2%, 5% and 8% PEG have porosity percentages of 51.54%, 68.70% and 73.50%, respectively. As the membrane with 2% PEG has the lowest percent porosity, it has more potential in removing or filtering solutes from a fluid.

Effect of Mercerization on the Properties of Cellulose Fiber and Cellulose Hydrogel Extracted from Pineapple Leaf Fiber

AbstractThis study investigated the effects of alkaline treatment on the pineapple leaf fiber (PALF) cellulose extraction and the properties of cellulose hydrogel. PALF was treated with different concentrations of sodium hydroxide (NaOH) (2 to 10 wt %) and at room temperature (RT) and 80 °C. Then, extracted cellulose was then dissolved in N,N’‐dimethyl acetamide (DMAc)/lithium chloride (LiCl) solvent system and formed into hydrogel by phase inversion method. The Fourier transform infrared spectra shows the peak disappearance at 1606 cm−1 proves that lignin was removed starting from 6 and 4 wt % NaOH at RT and 80 °C, respectively. Higher NaOH concentrations treatment increased thermal stability and the crystallinity (71 to 79 %) of the fibers. Higher NaOH concentration and treatment temperature enhanced cellulose extraction from PALF, leading to more physical crosslinking during hydrogel formation. High amount of cellulose extracted decreased the hydrogel's swelling equilibrium and increased the gel fraction. The highest transmittance (87.8 %) and the lowest intensity of absorbance (at 280 nm corresponding to lignin) were obtained by the hydrogel prepared with PALF treated with 8 wt % NaOH at 80 °C. Clearly, this research findings provide new insights into optimizing cellulose extraction using alkaline treatment specifically for cellulose hydrogel formation.

Solar light-induced photocatalytic degradation of 2,4-dichlorophenoxyacetic acid using chitosan/g-C3N4 beads

Remediation of persistent organic pollutants such as pesticides and personal care products in water has attained immense research interest due to the commercialization feasibility of Advanced Oxidation Processes. Thus, the present study focuses on the solar-light assisted photocatalytic degradation of commonly used pesticide, i.e., 2,4-dichlorophenoxyacetic acid. The chitosan-modified g-C3N4 beads (CS/g-C3N4) were synthesized using the phase inversion method. Synergistic activity of chitosan with g-C3N4 in the form of recoverable beads with solar light-based photocatalytic activity has been brought as the novelty of this work. The chitosan-modified g-C3N4 beads have been studied for their morphological and structural characterization. The diffuse reflectance spectroscopy shows the variation in the bandgap from 2.79 (g-C3N4) to 2.6 eV (CS/g-C3N4 beads) due to the incorporation of chitosan. The photocatalytic removal of 2,4-D under solar light using CS/g-C3N4 is found to be 83 %. The prepared beads showed no significant loss in catalytic activity even after four cycles. Therefore, CS/g-C3N4 is a low-cost, affordable, and environmentally friendly material for the redemption of pesticides like 2,4-D.