Browsing by Author "Siddique, I."

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Antibiofouling hollow-fiber membranes for dye rejection by embedding chitosan and silver-loaded chitosan nanoparticles
(Springer Verlag, 2019) Kolangare, I.M.; Isloor, A.M.; Zulhairun, Z.A.; Kulal, A.; A.F., A.F.; Siddique, I.; Asiri, A.M.
The removal of toxic dyes from the wastewater and industrial effluents is a major environmental challenge. Various techniques have been employed for the removal of dyes, including the application of nano-sized adsorbents, nanocomposite membranes and photodegradation. Membrane filtration is an alterntive but suffers from drawbacks such as fouling. Here we present a simple approach for the development of antibiofouling membranes based on chitosan. The application of chitosan-based nanoparticles as additives for wastewater treatment is poorly explored. The chitosan and silver-loaded chitosan nanoparticles were synthesized by ionic gelation method and incorporated to fabricate hollow-fiber membranes by dry–wet spinning technique. The prepared membranes were characterized by morphological study, permeability test, antibiofouling study and dye rejection study. The nanocomposite hollow-fiber membranes displayed superior performance than their pristine form. The incorporation of 0.30 weight percent of the chitosan and silver-loaded chitosan nanoparticles into the hollow-fiber membranes enhanced the antifouling property with flux recovery ratio of 81.21 and 86.13%, respectively. The dye rejection results showed maximum rejection of 89.27 and 86.04% for Reactive Black 5 and Reactive Orange 16, respectively. Hence, it can be concluded that hollow-fiber membranes with silver-loaded chitosan nanoparticles are pertinent in developing antibiofouling membranes for the treatment of industrial dye effluents. © 2018, Springer Nature Switzerland AG.
Assessment of sulfonated homo and co-polyimides incorporated polysulfone ultrafiltration blend membranes for effective removal of heavy metals and proteins
(Nature Research, 2020) Jafar Mazumder, M.A.; Raja, P.H.; Isloor, A.M.; Muhammad, M.; Chowdhury, S.H.; Ali, S.A.; Siddique, I.; Al-Ahmed, A.
Sulfonated homo and co- polyimide (sPI) were synthesized with new compositional ratios, and used as additives (0.5 wt%, 0.75 wt%, and 1.0 wt%) to prepare blend membranes with polysulfone (PSf). Flat sheet membranes for ultrafiltration (UF) were casted using the phase inversion technique. Surface morphology of the prepared UF membranes were characterized by atomic force microscopy (AFM) and scanning electron microscopy (SEM). Surface charge of the membranes were determined by zeta potential, and hydrophilicity was studied by contact angle measurement. The contact angle of the membrane decreased with increasing sPI additive indicates increasing the hydrophilicity of the blend membranes. Filtration studies were conducted for rejection of heavy metals (Pb2+ and Cd2+) and proteins (pepsin and BSA). Blend membranes showed better rejection than pure PSf membrane. Among the blend membranes it was observed that with increasing amount of sPIs enhance the membrane properties and finally, PSf-sPI5 membrane with 1 wt% of sPI5 showed the improved permeability (72.1 L m?2 h?1 bar?1), and the best rejection properties were found for both metal ions (?98% of Pb2+; ?92% of Cd2+) and proteins (>98% of BSA; > 86% of Pepsin). Over all, this membrane was having better hydrophilicity, porosity and higher number of sites to attach the metal ions. Its performance was even better than several-reported sulfonic acid based UF membranes. All these intriguing properties directed this new UF membrane for its potential application in wastewater treatment. © 2020, The Author(s).
Carbon nanotube- and graphene-based advanced membrane materials for desalination
(Springer Verlag, 2017) Hebbar, R.S.; Isloor, A.M.; Siddique, I.; Asiri, A.M.
The development of membrane-based desalination and water purification technologies offers new alternatives to meet the global freshwater demand. Rapid advancement in carbon nanotube-based and graphene-based nanomaterials has drawn the attention of scientific investigators on various desalination technologies. These nanomaterials indeed offer advantageous structure, size, shape, porosity and mass transport behavior for membrane separation process. This article reviews theoretical and experimental investigations of carbon nanotube- and graphene-based composite materials for desalination. Special attention is given to the simulation of molecular transport through these materials. Further, recent advances in the application of functionalization of carbon nanotube- and graphene-based materials for salt rejection and hydraulic permeation properties are discussed. © 2017, Springer International Publishing AG.
Fabrication of polyetherimide nanocomposite membrane with amine functionalised halloysite nanotubes for effective removal of cationic dye effluents
(Taiwan Institute of Chemical Engineers, 2018) Hebbar, R.S.; Isloor, A.M.; Siddique, I.; Abdullah, M.S.; A.F., A.F.; Asiri, A.M.
Naturally, occurring, low cost and eco-friendly halloysite nanotubes were chemically modified and uniformly immobilised into the polyetherimide membrane matrix with the aim of enhancing the properties and possible cationic dye rejection efficacy. The properties of fabricated nanocomposite membranes were examined by means of porosity, hydrophilicity, zeta potential and permeability. Permeation experiments revealed the enhanced water flux up to 195 L/m2h with 4 wt% additive dosage. The dye rejection efficacy of the prepared membranes was determined by using rhodamine B (Rh.B) and methylene blue (MB). The dye rejection studies were executed in terms of pH, contact time and initial dye concentration. The membrane with 4 wt% of nanomaterial dosage, showed rejection of 97% at pH 8 and 94% at pH 7 for MB and Rh.B dyes, respectively. Langmuir adsorption isotherm is the best model to explain interaction between dye molecules and membrane surface, with quantity of dye adsorbed (qmax) was observed to be 20.4 mg/g and 19.6 mg/g for MB and Rh.B, respectively. This approach showed modified membrane has good cationic dye rejection efficacy and can be efficiently employed to remove the dyes from aqueous streams. © 2018 Taiwan Institute of Chemical Engineers
Green sustainable process for chemical and environmental engineering and science: Supercritical carbon dioxide as green solvent
(Elsevier, 2019) Siddique, I.; Asiri, A.M.; Isloor, A.M.
Green Sustainable Processes for Chemical and Environmental Engineering and Science: Supercritical Carbon Dioxide as Green Solvent provides an in-depth review on the area of green processes for the industry, focusing on the separation, purification and extraction of medicinal, biological and bioactive compounds utilizing supercritical carbon dioxide as a green solvent and their applications in pharmaceuticals, polymers, leather, paper, water filtration, textiles and more. Chapters explore polymerization, polymer composite production, polymer blending, particle production, microcellular foaming, polymer processing using supercritical carbon dioxide, and a method for the production of micro- and nano-scale particles using supercritical carbon dioxide that focuses on the pharmaceutical industry. A brief introduction and limitations to the practical use of supercritical carbon dioxide as a reaction medium are also discussed, as are the applications of supercritical carbon dioxide in the semiconductor processing industry for wafer processing and its advantages and obstacles. Â© 2020 Elsevier Inc. All rights reserved.
Improved desalination by polyamide membranes containing hydrophilic glutamine and glycine
(Springer Science and Business Media Deutschland GmbH, 2019) Kolangare, I.M.; Isloor, A.M.; Siddique, I.; Asiri, A.M.; A.F., A.F.
Water desalination and recycling of wastewater is a key challenge to meet water shortage issues. Thin film composite polyamide membranes are widely used for desalination; however, their low permeability due to a poor hydrophilicity is a major drawback. Here, we designed novel thin film composite membranes having good hydrophilicity, permeability, and stability without compromising solute rejection. We improved the membrane hydrophilicity by incorporation of hydrophilic additives, such as glycine and l-glutamine, into the polyamide layer. Hence polyamide-based flat sheet membranes were fabricated via interfacial polymerization of m-phenylenediamine and trimesoyl chloride and then were coated over a polysulfone/sulfonated polyphenylsulfone (85:15) support. Polyamide membranes were then characterized and tested for desalination. Results show that the ridge and valley structure observed by scanning electron microscopy confirms the formation of the polyamide layer on membrane surface. The performance reached the highest pure water flux of 36.23 Lm?2 h?1 and flux recovery ratio of 89.18% for membranes with 2 wt% of l-glutamine. Incorporation of 2 wt% l-glutamine induced a high permeate flux and a maximum rejection of 87.87% for MgSO4, 83.50% for Na2SO4 and 60.77% for NaCl solutions. Overall, the polyamide nanofiltration membrane with hydrophilic groups displayed superior antifouling property and can be used as a potential candidate for desalination. © 2018, Springer Nature Switzerland AG.
Improved separation of dyes and proteins using membranes made of polyphenylsulfone/cellulose acetate or acetate phthalate
(Springer Science and Business Media Deutschland GmbH, 2020) Kumar, M.; Isloor, A.M.; Todeti, S.R.; Gnani Peer Mohamed, G.P.S.; Siddique, I.; A.F., A.F.; Asiri, A.M.
Industrial wastewater often contains xenobiotics such as heavy metals, dyes and proteins, yet there is a lack of efficient cleaning methods. Therefore, here we fabricated hollow fiber membranes using polyphenylsulfone containing 1, 3 and 5 wt% of cellulose acetate and cellulose acetate phthalate by non-solvent induced phase separation. Membrane morphology was characterized by field emission scanning electron microscopy. The hydrophilicity of the membranes was measured by contact angle, water uptake and porosity measurement. The thermal miscibility of the membrane with additives was assessed by thermogravimetric analysis. Hollow fiber membranes were tested for separation of azo dyes, e.g., reactive orange 16 and reactive black 5, and of proteins: bovine serum albumin, egg albumin and pepsin. Results show increasing rejection of dyes and proteins with the content of cellulose acetate and cellulose acetate phthalate. Water permeability was 41.26 L/m2 h bar for the polyphenylsulfone membrane, 64.47 L/m2 h bar for the polyphenylsulfone/5 wt% cellulose acetate membrane and 72.60 L/m2 h bar for the polyphenylsulfone/5 wt% cellulose acetate phthalate membrane. © 2020, Springer Nature Switzerland AG.
Nanohydroxyapatite Reinforced Chitosan Composite Hydrogel with Tunable Mechanical and Biological Properties for Cartilage Regeneration
(Nature Publishing Group Houndmills Basingstoke, Hampshire RG21 6XS, 2019) Kumar, B.Y.S.; Isloor, A.M.; Mohan Kumar, G.C.M.; Siddique, I.; Asiri, A.M.
With the continuous quest of developing hydrogel for cartilage regeneration with superior mechanobiological properties are still becoming a challenge. Chitosan (CS) hydrogels are the promising implant materials due to an analogous character of the soft tissue; however, their low mechanical strength and durability together with its lack of integrity with surrounding tissues hinder the load-bearing application. This can be solved by developing a composite chitosan hydrogel reinforced with Hydroxyapatite Nanorods (HANr). The objective of this work is to develop and characterize (physically, chemically, mechanically and biologically) the composite hydrogels loaded with different concentration of hydroxyapatite nanorod. The concentration of hydroxyapatite in the composite hydrogel was optimized and it was found that, reinforcement modifies the hydrogel network by promoting the secondary crosslinking. The compression strength could reach 1.62 ± 0.02 MPa with a significant deformation of 32% and exhibits time-dependent, rapid self-recoverable and fatigue resistant behavior based on the cyclic loading-unloading compression test. The storage modulus value can reach nearly 10 kPa which is needed for the proposed application. Besides, composite hydrogels show an excellent antimicrobial activity against Escherichia coli, Staphylococcus aureus bacteria’s and Candida albicans fungi and their cytocompatibility towards L929 mouse fibroblasts provide a potential pathway to developing a composite hydrogel for cartilage regeneration. © 2019, The Author(s).
Novel polyphenylsulfone (PPSU)/nano tin oxide (SnO2) mixed matrix ultrafiltration hollow fiber membranes: Fabrication, characterization and toxic dyes removal from aqueous solutions
(Elsevier B.V., 2019) Nayak, M.C.; Isloor, A.M.; Siddique, I.; Balakrishna Prabhu, B.; Ismail, N.I.; Asiri, A.M.
Novel polyphenylsulfone (PPSU)/nano tin oxide (SnO2) mixed matrix hollow fiber membranes (HFMs) were fabricated by dry-wet spinning via phase separation method. In the current research, reported the contrast between neat PPSU membrane and nanocomposite membranes (PPSU/SnO2), to determine the toxic reactive dyes namely, reactive black-5 (RB-5) and reactive orange-16 (RO-16) removal ability from the aqueous media. Scanning electron microscopy (SEM) was used to observe the HFMs cross-sectional morphological changes and surface roughness parameters of membranes were analyzed using atomic force microscopy (AFM). The surface wettability ability of HFMs was examined with a contact angle, water uptake, and porosity measurements. The cross-flow filter unit was engaged to quantify the water permeability, anti-fouling ability as well as the dye rejection ability of fabricated membranes. With increasing the SnO2 NPs wt% in PPSU polymer matrix the membrane performance was enhanced continuously, it became evident that the incorporated SnO2 NPs plays main role in membrane performance. Added, water-soluble poly (vinylpyrrolidone) (PVP) can also impact the pore morphology in membranes. At the end, PS-3 membrane exhibited lower contact angle (63.7 0), higher water uptake (74.8%), porosity (84.1%), pure water flux 362.9 L/m2 h, and high potential for dyes rejection application, of about >94% for RB-5, and >73% for RO-16 dye, respectively. From the preliminary results, it can be stated that the usage of SnO2 NPs in membrane technology become effective towards wastewater treatment. © 2019 Elsevier B.V.
Novel, one-step synthesis of zwitterionic polymer nanoparticles via distillation-precipitation polymerization and its application for dye removal membrane
(Nature Publishing Group Houndmills Basingstoke, Hampshire RG21 6XS, 2017) Gnani Peer Mohamed, G.P.S.; Isloor, A.M.; Siddique, I.; Asiri, A.M.; Ismail, N.; A.F., A.F.; Ashraf, G.M.
In this work, poly(MBAAm-co-SBMA) zwitterionic polymer nanoparticles were synthesized in one-step via distillation-precipitation polymerization (DPP) and were characterized. [2-(methacryloyloxy)ethyl]dimethyl-(3-sulfopropyl)ammonium hydroxide (SBMA) as monomer and N, N?-methylene bis(acrylamide) (MBAAm) as cross-linker are used for the synthesis of nanoparticles. As far as our knowledge, this is the first such report on the synthesis of poly(MBAAm-co-SBMA) nanoparticles via DPP. The newly synthesized nanoparticles were further employed for the surface modification of polysulfone (PSF) hollow fiber membranes for dye removal. The modified hollow fiber membrane exhibited the improved permeability (56 L/ m2 h bar) and dye removal (>98% of Reactive Black 5 and >80.7% of Reactive orange 16) with the high permeation of salts. Therefore, the as-prepared membrane can have potential application in textile and industrial wastewater treatment. © 2017 The Author(s).
Performance intensification of the polysulfone ultrafiltration membrane by blending with copolymer encompassing novel derivative of poly(styrene-co-maleic anhydride) for heavy metal removal from wastewater
(Elsevier B.V., 2018) Gnani Peer Mohamed, G.P.S.; Isloor, A.M.; Siddique, I.; Asiri, A.M.; A.F., A.F.; Kumar, R.; Ahamed, M.I.
A simple, scalable, novel polymer was synthesized by the aminolysis of poly(styrene-co-maleic anhydride) cumene terminated (PSMAC) using p-aminohippuric acid. The main objective was to perceive the effect of blend ratio of polysulfone (PSF) and poly[styrene-alt-(N-4-benzoylglycine-maleamic acid)] cumene terminated (PAH) on morphology and permeation properties of the membranes. The PSF/PAH blend membranes unveiled enriched hydrophilicity, porosity, zeta potential, water uptake and permeability owing to the existence of the hydrophilic PAH. However, the contact angle was not diminished over 20% of PAH ratio as there was an increase of hydrophobic alkyl group density. Differential scanning calorimetry (DSC) was employed for the determination of the glass transition temperature of the blends and the results revealed that the polymer blend is miscible in nature. Moreover, the M-3 membrane was screened for the heavy metal ion removal and achieved removal of 91.5% of Pb2+ and 72.3% of Cd2+ ions, respectively. The adsorption parameters indicated that the Langmuir isotherm model fits well for both Pb2+ and Cd2+ ions adsorption on M-3 membrane. The adsorption capacity attained from Langmuir isotherm model was 19.35 and 9.88 mg/g for Pb2+ and Cd2+ ions correspondingly. © 2018 Elsevier B.V.
Pervaporation dehydration of bio-fuel (n-butanol) by dry thermal treatment membrane
(Institute of Physics Publishing helen.craven@iop.org, 2020) Manshad, S.; Isloor, A.M.; Mohd Nawawi, M.G.; Siddique, I.; Khan, I.; Marwani, H.M.
In the present investigation, laboratory synthesized graphene oxide (GO) as a nano-filler was used in polyetherimide (PEI) flat-sheet membranes (PM). The PEI flat-sheet membrane was fabricated through a dry-thermal treatment (DTT) method. The effects of fabrication method were investigated on polyetherimide-GO membrane prepared by dry-thermal treatment (PMDTT). The morphological structure was investigated via different characterization; Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), X-ray diffraction (XRD), transmission electron microscopy (TEM), contact angle measurement and Raman spectra. The results indicated that, the hybrid PMDTT membrane displayed reasonably better pervaporation separation performance in comparison to neat PMDTT membranes. The concentrations of water at the permeate side of hybrid and neat PMDTT membrane were 99.3 and 90.9 wt.%, respectively. Hybrid membranes showed a 78.3% enhanced permeation rate. Enhancement of pervaporation property of hybrid PMDTT membrane could be ascribed mainly due to the presence of graphene oxide in the dense top layer. Overall, the blending of graphene oxide in hybrid PMDTT membranes could be a promising approach for enhancing the pervaporation properties of the membranes. © 2020 The Author(s). Published by IOP Publishing Ltd.
Polyphenylsulfone/multiwalled carbon nanotubes mixed ultrafiltration membranes: Fabrication, characterization and removal of heavy metals Pb2+, Hg2+, and Cd2+ from aqueous solutions
(Elsevier B.V., 2020) Chandrashekhar Nayak, M.; Isloor, A.M.; Siddique, I.; Lakshmi, B.; Marwani, H.M.; Khan, I.
Polyphenylsulfone/multiwalled carbon nanotubes/polyvinylpyrrolidone/1-methyl-2-pyrrolidone mixed matrix ultrafiltration flat-sheet membranes were fabricated via phase inversion process to inspect the heavy metals separation efficacy from aqueous media. Fabricated membranes cross-sectional morphological changes and the topographical alterations were assessed with Scanning electron microscopy (SEM) and atomic force microscopy (AFM). Particularly, MWCNTs assisted membranes exhibited better permeability ability as well as heavy metal removal enactment than virgin membrane. The dead-end filter unit was engaged in current research to examine the permeability and heavy metal removal competence of membranes. With the continuous enhancement of MWCNTs wt% in a polymer matrix, significant enhancement was observed with pure water flux study, from 41.69 L/m2 h to >185 L/m2 h as well as with the heavy metals separation study. Added additive MWCNTs can impact the pore sizes in membranes. The heavy metal separation results achieved, the membrane with 0.3 wt% of MWCNTs (PCNT-3) exhibited >98%, >76% and >72% for Pb2+, Hg2+ and Cd2+ ions, respectively. Overall, MWCNTs introduced PPSU membranes exposed best outcomes with heavy metals contained wastewater treatment. © 2019 The Authors
Removal of metal ions and humic acids through polyetherimide membrane with grafted bentonite clay
(Nature Publishing Group Houndmills Basingstoke, Hampshire RG21 6XS, 2018) Hebbar, R.S.; Isloor, A.M.; Balakrishna Prabhu, B.; Siddique, I.; Asiri, A.M.; A.F., A.F.
Functional surfaces and polymers with branched structures have a major impact on physicochemical properties and performance of membrane materials. With the aim of greener approach for enhancement of permeation, fouling resistance and detrimental heavy metal ion rejection capacity of polyetherimide membrane, novel grafting of poly (4-styrenesulfonate) brushes on low cost, natural bentonite was carried out via distillation-precipitation polymerisation method and employed as a performance modifier. It has been demonstrated that, modified bentonite clay exhibited significant improvement in the hydrophilicity, porosity, and water uptake capacity with 3 wt. % of additive dosage. SEM and AFM analysis showed the increase in macrovoides and surface roughness with increased additive concentration. Moreover, the inclusion of modified bentonite displayed an increase in permeation rate and high anti-irreversible fouling properties with reversible fouling ratio of 75.6%. The humic acid rejection study revealed that, PEM-3 membrane having rejection efficiency up to 87.6% and foulants can be easily removed by simple hydraulic cleaning. Further, nanocomposite membranes can be significantly employed for the removal of hazardous heavy metal ions with a rejection rate of 80% and its tentative mechanism was discussed. Conspicuously, bentonite clay-bearing poly (4-styrenesulfonate) brushes are having a synergistic effect on physicochemical properties of nanocomposite membrane to enhance the performance in real field applications. © 2018 The Author(s).
Tuning the surface properties of Fe3O4 by zwitterionic sulfobetaine: application to antifouling and dye removal membrane
(Springer, 2020) Gnani Peer Mohamed, G.P.; Isloor, A.M.; Siddique, I.; Asiri, A.M.; Farnood, R.
In this paper, zwitterionic polysulfobetaine@Fe3O4 (PSBMA@Fe3O4) nanoparticles were synthesized via covalent grafting and free radical polymerization and characterized. The PSBMA@Fe3O4 noparticles had a zeta potential of ? 36 mV (pH 6.3), which guaranteed the high colloidal stability. The as-synthesized nanoparticles were employed as a nanofiller to prepare superior antifouling polysulfone hybrid hollow fiber membranes. The FM-2 membrane exhibited the maximum pure water permeability of 61.1 L/m2 h bar with humic acid (HA) removal efficiency of 98%. The fouling resistance was evaluated using HA as a foulant, and the results suggested that the FM-2 membrane had less amount of HA adsorption with flux recovery ratio of 88.4%. Furthermore, the FM-2 membrane was demonstrated the reactive black-5 and reactive orange-16 removal of above 99% and 84% without much reduction in the dye solution permeability. © 2020, Islamic Azad University (IAU).
Use of cellulose acetate/polyphenylsulfone derivatives to fabricate ultrafiltration hollow fiber membranes for the removal of arsenic from drinking water
(Elsevier B.V., 2019) Kumar, M.; Todeti, S.; Isloor, A.M.; Gnani Peer Mohamed, G.P.S.; Siddique, I.; Ismail, N.I.; A.F., A.F.; Asiri, A.M.
Cellulose acetate (CA) and cellulose acetate phthalate (CAP) were used as additives (1 wt%, 3 wt%, and 5 wt%) to prepare polyphenylsulfone (PPSU) hollow fiber membranes. Prepared hollow fiber membranes were characterized by surface morphology using scanning electron microscopy (SEM), surface roughness by atomic force microscopy (AFM), the surface charge of the membrane was analyzed by zeta potential measurement, hydrophilicity by contact angle measurement and the functional groups by fourier transform infrared spectroscopy (FTIR). Fouling resistant nature of the prepared hollow fiber membranes was evaluated by bovine serum albumin (BSA) and molecular weight cutoff was investigated using polyethylene glycol (PEG). By total organic carbon (TOC), the percentage rejection of PEG was found to be 14,489 Da. It was found that the hollow fiber membrane prepared by the addition of 5 wt% of CAP in PPSU confirmed increased arsenic removal from water as compared to hollow fiber membrane prepared by 5 wt% of CA in PPSU. The removal percentages of arsenic with CA-5 and CAP-5 hollow fiber membrane was 34% and 41% with arsenic removal permeability was 44.42 L/m2h bar and 40.11 L/m2h bar respectively. The increased pure water permeability for CA-5 and CAP-5 hollow fiber membrane was 61.47 L/m2h bar and 69.60 L/m2 h bar, respectively. © 2019 Elsevier B.V.