Functionalized organic filler based integrated membranes for environmental remediation.

Mixed matrix membranes (MMMs) are synthesized for efficient CO2 separation released from various anthropogenic sources, which are due to global environmental concerns. The synergetic effect of porous nitrogen-rich, CO2-philic filler and polymer in mixed matrix-based membranes (MMMs) can separate CO2 competent. The development of various loadings of porphyrin poly(N-isopropyl Acryl Amide) (P-NIPAM)as functionalized organic fillers (5-20%) in polysulfone (PSU) through solution casting is carried out followed by the various characterizations including field emission scanning electron microscopy (FESEM), X-ray diffraction analysis (XRD), Fourier Transform Infrared Spectrometer(FT-IR) analysis and pure and mixed gas permeations ranging from 2 to 10 bar feed pressure. Due to both organic species interactions in the matrix, well-distributed fillers and homogenous surfaces, and cross-sectional structures were observed due to π-π interactions and Lewis's basic functionalities. The strong affinity of porous nitrogen-rich and CO2-philic fillers through gas permeation analysis showed high CO2/CH4 and CO2/N2 gas performance that surpassed Robeson's upper bound limit. Comparatively, MMMs showed improved CO2/CH4 permeabilities from 87.5 ± 0.5 Barrer to 88.2 ± 0.9 Barrer than pure polymer matrix. For CO2/N2, CO2 permeabilities improved to 75 ± 0.8 Barrer than pure polymer matrix. For both gas pairs (CO2/CH4, CO2/N2), respective pureselectivities (84%; 86%) and binary selectivities (85% and 85%)were improved. Various theoretical gas permeation models were used to predict CO2 permeabilities for MMMs from which the modified Maxwell-Wagner-Sillar model showed the least AARE% of 0.87. The results showed promising results for efficient CO2 separation due to exceptional functionalized P-PNIPAM affinitive properties. Finally, cost analysis reflected the inflated cost of membranes production for industrial setup using indigenous resources.

One pot synthesis of UiO-66@IL composite for fabrication of CO2 selective mixed matrix membranes.

In this study, a facile and extensible one pot approach was utilized to synthesize ionic liquid inside a porous metal organic framework (UiO-66). Different characterization techniques were used to confirm the successful synthesis of UiO-66@IL composite. The MMMs were characterized and tested for CO2 separation from CH4 or N2 at ambient and elevated temperatures. SEM images exhibited well dispersion of the filler particles with no notable defect even at high loadings. Single and mixed gas permeation results indicated significant performance (CO2 permeability: 143 Barrer and CO2/CH4, CO2/N2 selectivity: 28.32, 61.11 respectively) by enhancing the permeability of CO2 by 74% and selectivity to 31% and 26% for CO2/CH4 and CO2/N2 compared with neat Pebax®1657 membrane.

Challenges and recent trends with the development of hydrogel fiber for biomedical applications.

Hydrogel is the most emblematic soft material which possesses significantly tunable and programmable characteristics. Polymer hydrogels possess significant advantages including, biocompatible, simple, reliable and low cost. Therefore, research on the development of hydrogel for biomedical applications has been grown intensely. However, hydrogel development is challenging and required significant effort before the application at an industrial scale. Therefore, the current work focused on evaluating recent trends and issues with hydrogel development for biomedical applications. In addition, the hydrogel's development methodology, physicochemical properties, and biomedical applications are evaluated and benchmarked against the reported literature. Later, biomedical applications of the nano-cellulose-based hydrogel are considered and critically discussed. Based on a detailed review, it has been found that the surface energy, intermolecular interactions, and interactions of hydrogel adhesion forces are major challenges that contribute to the development of hydrogel. In addition, compared to other hydrogels, nanocellulose hydrogels demonstrated higher potential for drug delivery, 3D cell culture, diagnostics, tissue engineering, tissue therapies and gene therapies. Overall, nanocellulose hydrogel has the potential for commercialization for different biomedical applications.

Phyllosilicate derived catalysts for efficient conversion of lignocellulosic derived biomass to biodiesel: A review.

The efforts have been made to review phyllosilicate derived (clay-based) heterogeneous catalysts for biodiesel production via lignocellulose derived feedstocks. These catalysts have many practical and potential applications in green catalysis. Phyllosilicate derived heterogeneous catalysts (modified via any of these approaches like acid activated clays, ion exchanged clays and layered double hydroxides) exhibits excellent catalytic activity for producing cost effective and high yield biodiesel. The combination of different protocols (intercalated catalysts, ion exchanged catalysts, acidic activated clay catalysts, clay-supported catalysts, composites and hybrids, pillared interlayer clay catalysts, and hierarchically structured catalysts) was implemented so as to achieve the synergetic effects (acidic-basic) in resultant material (catalyst) for efficient conversion of lignocellulose derived feedstock (non-edible oils) to biodiesel. Utilisation of these Phyllosilicate derived catalysts will pave path for future researchers to investigate the cost-effective, accessible and improved approaches in synthesising novel catalysts that could be used for converting lignocellulosic biomass to eco-friendly biodiesel.

Treatment of Hospital wastewater with submerged aerobic fixed film reactor coupled with tube-settler.

In this study, Hospital wastewater was treated using a submerged aerobic fixed film (SAFF) reactor coupled with tubesettler in series. SAFF consisted of a column with an up-flow biofilter. The biological oxygen demand (BOD)5, chemical oxygen demand (COD), nitrate and phosphate were the chosen pollutants for evaluation. The pollutants removal efficiency was determined at varying organic loading rates and hydraulic retention time. The organic loading rate was varied between 0.25 and 1.25 kg COD m-3 d-1. The removal efficiency of SAFF and tubesettler combined was 75 % COD, 67 % BOD and 67 % phosphate, respectively. However, nitrate saw an increase in concentration by 25 %. SAFF contribution in the removal of COD, BOD5 and Phosphate was 48 %, 46 % and 29 %, respectively. While for accumulation of nitrate, it was responsible for 56%, respectively. Tubesettler performed better than SAFF with 52 %, 54 % and 69 % reduction of COD, BOD5 and phosphate, respectively. But in terms of nitrate, tubesettler was responsible for 44 % accumulation. The nutrient reduction decreased with an increase in the organic loading rate. Nitrification was observed in the SAFF and tubesettler, which indicated a well-aerated system. An anaerobic unit is required for completing the denitrification process and removing nitrogen from the effluent. The better performance of tubesettler over SAFF calls for necessitates extended retention time over design criteria. Further studies are beneficial to investigate the impact of pharmaceutical compounds on the efficiency of SAFF.

A review on sensing and catalytic activity of nano-catalyst for synthesis of one-step ammonia and urea: Challenges and perspectives.

One of the most significant chemical operations in the past century was the Haber-Bosch catalytic synthesis of ammonia, a fertilizer vital to human life. Many catalysts are developed for effective route of ammonia synthesis. The major challenges are to reduce temperature and pressure of process and to improve conversion of reactants produce green ammonia. The present review, briefly discusses the evolution of ammonia synthesis and current advances in nanocatalyst development. There are promising new ammonia synthesis catalysts of different morphology as well as magnetic nanoparticles and nanowires that could replace conventional Fused-Fe and Promoted-Ru catalysts in existing ammonia synthesis plants. These magnetic nanocatalyst could be basis for the production of magnetically induced one-step green ammonia and urea synthesis processes in future.

Future advances and challenges of nanomaterial-based technologies for electromagnetic interference-based technologies: A review.

The emerging growth of the electronic devices applications has arisen the serious problems of electromagnetic (EM) wave pollution which resulting in equipment malfunction. Therefore, polymer-based composites have been considered good candidates for better EMI shielding due to their significant characteristics including, higher flexibility, ultrathin, lightweight, superior conductivity, easy fabrication processing, environmentally friendly, corrosion resistive, better adhesion with physical, chemical and thermal stability. This review article focused on the concept of the EMI shielding mechanism and challenges with the fabrication of polymer-based composites. Subsequently, recent advancements in the polymer composites applications have been critically reviewed. In addition, the impact of polymers and polymer nanocomposites with different fillers such as organic, inorganic, 2D, 3D, mixture and hybrid nano-fillers on EMI shielding effectiveness has been explored. Lastly, future research directions have been proposed to overcome the limitations of current technologies for further advancement in EMI shielding materials for industrial applications. Based on reported literature, it has been found that the low thickness based lightweight polymer is considered as a best material for excellent material for next-generation electronic devices. Optimization of polymer composites during the fabrication is required for better EMI shielding. New nano-fillers such as functionalization and composite polymers are best to enhance the EMI shielding and conductive properties.

Green synthesized nano-cellulose polyethylene imine-based biological membrane.

In hemodialysis process, membrane serves as a barrier between blood and the dialysate. The barrier when contacted by blood accompanied activation of coagulation, immunity, and cellular passageways. In the recent years, hemodialysis membrane's biocompatibility has become a issue which leads to reduce the performance during the separation process. In previous work, we developed and evaluated a cellulose-based membrane blended with polyaziridine or polyetyleneimine in formic acid for hydrophilicity, pure water flux, surface morphology, and permeation efficiency. Biocompatibility was accessed, by conducting cellular viability and cellular attachments tests. In this study, the membrane compared to a non-treated control, and cell viability revealed active and growing cell cultures after 14 days. During the cellular attachment experiment, cell cultures attached to the fabricated membrane simulated the formation of cell junctions, proving that the membrane is non-toxic and biocompatible. CA + PEI + FA membrane tested with a blood mimic fluid having density identical to renal patient's blood. The BSA concentration in the feed solution was the same as that in the blood of the renal patient. The results revealed that the CA + PEI + FA membrane was able to reject 99% bovine serum albumin (BSA) and 69.6% urea. Therefore, from biocompatibility and blood mimic fluid testing, it is confirmed that the CA + PEI + FA membrane is the finest implant for dialysis applications.

Effect of process parameters over carbon-based ZIF-62 nano-rooted membrane for environmental pollutants separation.

The paper evaluates the routes towards the evaluation of membranes using ZIF-62 metal organic framework (MOF) nano-hybrid dots for environmental remediation. Optimization of interaction of operating parameters over the rooted membrane is challenging issue. Subsequently, the interaction of operating parameters including temperature, pressure and CO2 gas concentration over the resultant rooted membranes are evaluated and optimized using response surface methodology for environmental remediation. In addition, the stability and effect of hydrocarbons on the performance of the resulting membrane during the gas mixture separation are evaluated at optimum conditions to meet the industrial requirements. The characterization results verified the fabrication of the ZIF-62 MOF rooted composite membrane. The permeation results demonstrated that the CO2 permeability and CO2/CH4 selectivity of the composite membrane was increased from 15.8 to 84.8 Barrer and 12.2 to 35.3 upon integration of ZIF-62 nano-glass into cellulose acetate (CA) polymer. Subsequently, the optimum conditions have been found at a temperature of 30 °C, the pressure of 12.6 bar and CO2 feed concentration of 53.3 vol%. These optimum conditions revealed the highest CO2 permeability, CH4 permeability and CO2/CH4 separation factor of 47.9 Barrer, 0.2 Barrer and 26.8. The presence of hydrocarbons in gas mixture dropped the CO2 permeability of 56.5% and separation factor of 46.4% during 206 h of testing. The separation performance of the composite membrane remained stable without the presence of hydrocarbons for 206 h.

Self-healing epoxy coating synthesis by embedment of metal 2-methyl imidazole and acetylacetonate complexes with microcapsules.

The restoration of mechanical properties is desired for creating the self-healing coatings with no corrosion capabilities. The encapsulation of epoxy resins is limited by various factors in urea and melamine formaldehyde microcapsules. An improved method was developed, where epoxy resin was encapsulated by individual wrapping of poly(melamine-formaldehyde) and poly(urea-formaldehyde) shell around emulsified epoxy droplets via oil-in-water emulsion polymerization method. The synthesized materials were characterized analytically. The curing of the epoxy was achieved by adding the [Ni/Co(2-MI)6].2NO3 as a latent hardener and iron acetylacetonate [Fe(acac)3] as a latent accelerator. Isothermal and non-isothermal differential scanning calorimetric analysis revealed lower curing temperature (Tonset = 116 °C) and lower activation energies (Ea ≈ 69-75 kJ/mol). The addition of microcapsules and complexes did not adversely alter the flexural strength and flexural modulus of the epoxy coatings. The adhesion strength of neat coating decreased from 6310.8 ± 31 to 4720.9 ± 60 kPa and percent healing increased from 50.83 to 67.45% in the presence of acetylacetonate complex at 10 wt% of microcapsules.

Fabrication and performance evaluation of polymeric membrane using blood compatible hydroxyapatite for artificial kidney application.

In the current study, a phase inversion scheme was employed to fabricate hydroxyapatite (HA)/polysulfone (PSF)-based asymmetric membranes using a film applicator with water as a solvent and nonsolvent exchanging medium. Fourier Transform Infrared (FTIR) and X-ray diffraction (XRD) spectroscopic studies were conducted to confirm the bonding chemistry and purity of filler. The inherent thick nature of PSF generated sponge-like shape while the instantaneous demixing process produced finger-like pore networks in HA/PSF-based asymmetric membranes as exhibited by scanning electron microscope (SEM) micrographs. The FTIR spectra confirmed noncovalent weak attractions toward the polymer surface. The leaching ratio was evaluated to observe the dispersion behavior of HA filler in membrane composition. Hydrophilicity, pore profile, pure water permeation (PWP) flux, and molecular weight cutoff (MWCO) values of all formulated membranes were also calculated. Antifouling results revealed that HA modified PSF membranes exhibited 43% less adhesion of bovine serum albumin (BSA) together with >86% recovery of flux. Membrane composition showed 74% total resistance, out of which 60% was reversible resistance. Biocompatibility evaluation revealed that the modified membranes exhibited prothrombin time (PT), and thrombin time (TT) comparable with typical blood plasma, whereas proliferation of living cells over membrane surface proved its nontoxic behavior toward biomedical application. The urea and creatinine showed effective adsorption aptitude toward HA loaded PSF membranes.

Sustainable mixed matrix membranes containing porphyrin and polysulfone polymer for acid gas separations.

The synergetic effect of nitrogen-rich and CO2-philic filler and polymer in mixed matrix-based membranes (MMMs) can separate CO2 competently. The introduction of well-defined nanostructured porous fillers of pores close to the kinetic diameter of the gas molecule and polymer matrix compatibility is a challenge in improving the gas transportation characteristics of MMMs. This study deals with the preparation of porphyrin filler and the polysulfone (PSf) polymer MMMs. The fillers demonstrated uniform distribution, uniformity, and successful bond formation. MMMs demonstrated high thermal stability with a glass transition temperature in the range of 480-610 °C. The porphyrin filler exhibited microporous nature with the presence of π-π bonds and Lewis's basic functionalities between filler-polymer resulted in a highly CO2-philic structure. The pure and mixed gas permeabilities and selectivity were successfully improved and surpass the Robeson's upper bound curve's tradeoff. Additionally, the temperature influence on CO2 permeability revealed lower activation energies at higher temperatures leading to the gas transport facilitation. This can be granted consistency and long-term durability in polymer chains. These results highlight the unique properties of porphyrin fillers in CO2 separation mixed matrix membranes and offer new knowledge to increase comprehension of PSf performance under various contents or environments.

Synthesis of biodiesel from non-edible (Brachychiton populneus) oil in the presence of nickel oxide nanocatalyst: Parametric and optimisation studies.

The present study defines a novel green method for the synthesis of the nickel oxide nanocatalyst by using an aqueous latex extract of the Ficus elastic. The catalyst was examined for the conversion of novel Brachychiton populneus seed oil (BPSO) into biodiesel. The Brachychiton populneus seeds have a higher oil content (41 wt%) and free fatty acid value (3.8 mg KOH/g). The synthesised green nanocatalyst was examined by the Fourier transform infrared (FT-IR) spectroscopy, energy dispersive X-Ray (EDX) spectroscopy, X-Ray diffraction (XRD) spectroscopy and scanning electron microscopy (SEM). The obtained results show that the synthesised green nanocatalyst was 22-26 nm in diameter and spherical-cubic in shape with a higher rate of catalytic efficiency. It was utilised further for the conversion of BPSO into biofuel. Due to the high free fatty acid value, the biodiesel was synthesised by the two-step process, i.e., pretreatment of the BPSO by means of acid esterification and then followed by the transesterification reaction. The acidic catalyst (H2SO4) was used for the pretreatment of BPSO. The optimum condition for the transesterification of the pretreated BPSO was 1:9 of oil-methanol molar ratio, 2.5 wt % of prepared nanocatalyst concentration and 85 °C of reaction temperature corresponding to the highest biodiesel yield of 97.5 wt%. The synthesised biodiesel was analysed by the FT-IR and GC-MS technique to determine the chemical composition of fatty acid methyl esters. Fuel properties of Brachychiton populneus seed oil biodiesel (BPSOB) were also examined, compared, and it falls in the prescribed range of ASTM standards.

Sustainable functionalized metal-organic framework NH2-MIL-101(Al) for CO2 separation under cryogenic conditions.

In this study, a sustainable NH2-MIL-101(Al) is synthesized and subjected to characterization for cryogenic CO2 adsorption, isotherms, and thermodynamic study. The morphology revealed a highly porous surface. The XRD showed that NH2-MIL-101(Al) was crystalline. The NH2-MIL-101(Al) decomposes at a temperature (>500 °C) indicating excellent thermal stability. The BET investigation revealed the specific surface area of 2530 m2/g and the pore volume of 1.32 cm3/g. The CO2 adsorption capacity was found to be 9.55 wt% to 2.31 wt% within the investigated temperature range. The isotherms revealed the availability of adsorption sites with favorable adsorption at lower temperatures indicating the thermodynamically controlled process. The thermodynamics showed that the process is non-spontaneous, endothermic, with fewer disorders, chemisorption. Finally, the breakthrough time of NH2-MIL-101(Al) is 31.25% more than spherical glass beads. The CO2 captured by the particles was 2.29 kg m-3. The CO2 capture using glass packing was 121% less than NH2-MIL-101(Al) under similar conditions of temperature and pressure.

A practical approach for synthesis of biodiesel via non-edible seeds oils using trimetallic based montmorillonite nano-catalyst.

The potential of new trimetallic (Ce, Cu, La) loaded montmorillonite clay catalyst for synthesizing biodiesel using novel non-edible Celastrus paniculatus Willd seed oil via two-step transesterification reaction has been reported along with catalyst characterization. Transesterification reaction was optimized and maximum biodiesel yield of 89.42% achieved under optimal operating reaction states like; 1:12 oil to methanol ratio, 3.5% of catalyst amount, 120 °C of reaction temperature for 3 h. The predicted and experimental biodiesel yields under these reaction conditions were 89.42 and 89.40%, which showing less than 0.05% variation. Additionally, optimum biodiesel yield can be predicted by drawing 3D surface plots and 2D contour plots using MINITAB 17 software. For the characterization of the obtained biodiesel, analysis including the GC/MS, FT-IR, 1H NMR and 13C NMR were applied. The fuel properties of obtained biodiesel agrees well with the different European Union (EU-14214), China (GB/T 20828), and American (ASTM-951, 6751) standards.

Biocompatibility performance evaluation of high flux hydrophilic CO3Ap/HAP/PSF composite membranes for hemodialysis application.

Carbonate apatite/hydroxyapatite (CO3Ap/HAP) additive was obtained by calcination of wasted chicken bones at 900°C. Intermolecular attraction exists between CO3Ap/HAP additive and blended polysulfone (PSF) polymer. Electron dispersive X-ray (EDX) and FTIR analysis were carried out to check the elemental composition and bonding chemistry of prepared additive. The instantaneous demixing process generated consistent finger-like networks in CO3Ap/HAP/PSF-based composite membranes while sponge-like structure was shown by PSF as revealed by SEM images. The increase in weight % of additive loading is also confirmed by EDX analysis. Furthermore, the interaction mechanism of CO3Ap/HAP additive with polysulfone medium was analyzed by FTIR exploration. The water absorption experiment defined a 93% expansion in hydrophilic performance. Change in porosity occurs with additive loading and pure water permeation flux improved up to 11 times. Approximately, antifouling results revealed that 87% of water flux was recovered after treating with a protein solution, whereas a 30% improvement in antifouling capability in case of bovine serum albumin solution occurred. In vitro cytotoxicity, and clotting times study was carried out to evaluate virulent behavior and anticoagulation activity of formulated membranes.

Adsorption behavior of mercury over hydrated lime: Experimental investigation and adsorption process characteristic study.

This study reports the application of hydrated lime for the effective adsorption of the heavy mercury metal from the aqueous phase solutions. Initially, hydrated lime was subjected to structural characterization and thermal stability analysis. The FT-IR spectrum analysis revealed that the existence of the O-H bonds as a confirmation of hydrated lime formation. Subsequently, the XRD powder-based analysis demonstrated that most of the hydrated lime is pure crystalline material known as Portlandite while a small amount of calcite is also present in the structure of the hydrated lime. The thermal stability analysis revealed that the hydrated lime is highly thermally stable under harsh conditions without decomposing at higher temperatures up to 500 °C. Furthermore, the hydrated lime was subjected to the selective adsorption of heavy metal mercury to investigate the potential influence of the adsorbent particle size and loading on adsorption capacity. The results demonstrated that the decrease in the adsorbent particle size leads to the improvement in the mercury adsorption attributing to the rise in specific surface area. The enhancement in the loading of the adsorbent resulted in a reduction in mercury adsorption directing to the fact that already adsorbed metal ions onto the adsorbent surface lead to hindrance for the adsorption of other ions of heavy metal. These results lead to a significant impact on modern in inventing different adsorbents with promising water treatment efficiency for more industrial applications and the related recovery of mercury.