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Item Preparation, characterization and performance study of poly(isobutylene- alt-maleic anhydride) [PIAM] and polysulfone [PSf] composite membranes before and after alkali treatment(2011) Padaki, M.; Isloor, A.M.; Belavadi, G.; Prabhu, K.N.Recently, nanofiltration (NF) membranes have been drawing much attention in the field of filtration and the purification process of water/industrial effluents, because of their energy efficiency and low cost. Although reverse osmosis (RO) membranes are widely used in present desalination units, NF membranes are considered as "future membranes" for desalination, because of the low operating pressure. In the present paper, we hereby report the synthesis of a new composite NF membranes of poly(isobutylene-alt-maleic anhydride) (PIAM) with polysulfone, using a diffusion-induced phase separation (DIPS) method. The anhydride groups were converted to acid group by alkaline treatment. Newly prepared composite membranes were characterized by Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), and differential scanning calorimetry (DSC) studies. The membranes were tested for salt rejection and water swelling. The resulted NF membranes exhibited significantly enhanced water permeability while retaining high salt rejection. The flux and rejection rate of the NF membrane to Na2SO4 (500 ppm) reached to 11.73 L/(m2 h) and 49% rejection under 1 MPa and also 70:30 composition of the membrane showed 54% water swelling; contact angle measurement, ion exchange capacity, and water uptake of the membrane were recorded. © 2011 American Chemical Society.Item A review on RO membrane technology: Developments and challenges(Elsevier B.V., 2015) Shenvi, S.S.; Isloor, A.M.; A.F., A.F.Reverse osmosis (RO) based desalination is one of the most important and widely recognized technologies for production of fresh water from saline water. Since its conception and initiation, a significant development has been witnessed in this technology w.r.t. materials, synthesis techniques, modification and modules over the last few decades. The working of a RO plant inclusive of the pretreatment and post-treatment procedures has been briefly discussed in the article. The main objective of this review is to highlight the historical milestones achieved in RO technology in terms of membrane performance, the developments seen over the last few years and the challenges perceived. The material properties of the membrane dominate the performance of a RO process. The emergence of nano-technology and biomimetic RO membranes as the futuristic tools is capable of revolutionizing the entire RO process. Hence the development of nano-structured membranes involving thin film nano-composite membranes, carbon-nanotube membranes and aquaporin-based membranes has been focussed in detail. The problems associated with a RO process such as scaling, brine disposal and boron removal are briefed and the measures adopted to address the same have been discussed. © 2014 Elsevier B.V.Item 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.Item A comprehensive review on evaporative cooling systems(Elsevier B.V., 2023) Kapilan, N.; Isloor, A.M.; Karinka, S.The evaporative cooling system (ECS) is one of the cheapest and oldest cooling technologies. The conventional single stage ECS is most widely used in domestic application, particularly in hot and dry regions. However, in this system, the temperature of the air cannot be reduced below the wet bulb temperature of the air. The multistage ECS system helps to overcome this problem. The combination of direct and indirect ECS helps to reduce the temperature of the air below its wet bulb temperature. The further reduction in air temperature may be achieved with the help of the cooling coil driven by vapour compression system. The energy consumed by the ECS is lower as compared to vapour compression refrigeration system. The ECS can be driven with the help of solar power. The conventional cooling pad used in ECS can be replaced with locally available natural fibers to reduce initial cost and to reduce dependence on import of cooling pads. The performance of the ECS can be improved with the help of heat pipe. Various techniques are used to enhance ECS's performance. The performance of the vapour compression refrigeration system can be improved with the help of ECS. This paper discusses basics and types of ECS, methods used to increase the performance of ECS, types of natural fiber cooling pad material, process variables affecting ECS, recent technical advancements, challenges and opportunities. © 2023 The AuthorsItem 5-Diethyl-amino-2-[(E)-(4-methyl-3-nitro-phenyl)-imino-meth-yl]phenol: A redetermination(2009) Fun, H.-K.; Kia, R.; Vijesh, A.M.; Isloor, A.M.The title compound, C18H21N3O3, is a potential bidentate Schiff base ligand. The whole mol-ecule is disordered with a refined site-occupancy ratio of 0.567 (4):0.433 (4) and not just one ethyl group as reported previously [Sarojini et al. (2007). Acta Cryst. E63, o4782-o4782]. Using the whole mol-ecule disorder, R values are much smaller than those published. An intra-molecular O - H?N hydrogen bond generates a six-membered ring, producing an S(6) ring motif. The dihedral angle between the mean plane of the two benzene rings (major component) is 9.0 (5)°. The crystal structure shows short C?C [3.189 (15)-3.298 (12) Å] and C?O [2.983 (5)-3.149 (13) Å] contacts. Inter-molecular C - H?O inter-actions link neighbouring mol-ecules into dimers with R 2 2(18) motifs. In the crystal structure, these dimers are linked together by inter-molecular C - H?O inter-actions into one-dimensional extended chains along the b axis. The crystal structure is further stabilized by inter-molecular ?-? stacking inter-actions [centroid-centroid distances = 3.458 (8)-3.691 (6) Å].Item 2-[(4-tert-Butyl-anilino)(phen-yl)meth-yl]cyclo-hexa-none(2009) Fun, H.-K.; Chantrapromma, S.; Rai, S.; Shetty, P.; Isloor, A.M.In the mol-ecule of the title compound, C23H29NO, the cyclo-hexa-none ring has been distorted from the standard chair conformation by the ketone group such that part of the ring is almost flat. The remaining [(4-tert-butyl-anilino)(phen-yl)meth-yl] portion of the mol-ecule is in an equatorial position on the cyclo-hexa-none ring. The dihedral angle between the two benzene rings is 81.52 (8)°. In the crystal packing, mol-ecules are linked by N - H?O hydrogen bonds into infinite one-dimensional chains along the a axis and these chains are stacked down the c axis. The crystal structure is further stabilized by weak C - H?O and C - H?? inter-actions.Item N-(1-Naphth-yl)-10H-9-oxa-1,3-diaza-anthracen-4-amine(2009) Fun, H.-K.; Chantrapromma, S.; Rai, S.; Shetty, P.; Isloor, A.M.In the mol-ecule of the title compound, C21H15N 3O, the 10H-9-oxa-1,3-diaza-anthracene ring system is slightly bent, with dihedral angles of 3.99 (6) and 4.80 (6)° between the pyran ring and the pyrimidine and benzene rings, respectively. This ring system makes a dihedral angle of 85.23 (3)° with the naphthalene plane. In the crystal packing, mol-ecules are linked by N - H?N hydrogen bonds into chains along the a axis and these chains are stacked along the b axis. The crystal is further stabilized by weak C - H?N and C - H?? inter-actions.Item (4-Chloro-2-fluoro-phen-yl)[1-(2,6-difluoro-phen-yl)but-3-en-yl]amine(2009) Fun, H.-K.; Rai, S.; Shetty, P.; Isloor, A.M.; Chantrapromma, S.In the mol-ecule of the title homoallylic amine, C16H 13ClF3N, the dihedral angle between the two benzene rings is 84.63 (4)°. Weak intra-molecular N - H?F hydrogen bonds generate S(6) and S(5) ring motifs. In the crystal structure, weak inter-molecuar N - H?F hydrogen bonds link mol-ecules into centrosymmetric dimers which are arranged in mol-ecular sheets parallel to the ac plane.Item Ethyl 2-[(4-chloro-phen-yl)hydrazono]-3-oxobutanoate(2009) Fun, H.-K.; Chantrapromma, S.; Padaki, M.; Radhika; Isloor, A.M.The mol-ecule of the title oxobutanoate derivative, C12H 13ClN2O3, is nearly planar; the inter-planar angle between the benzene ring and the mean plane through the hydrazono-3-oxobutanoate unit is 2.69 (3)°. An intra-molecular N - H?O hydrogen bond generates an S(6) ring motif. In the crystal packing, C - H?O(3-oxo) inter-actions link mol-ecules into dimers. The dimers thus formed are linked through C - H?O(carboxyl-ate C=O) inter-actions, leading to the formation of ribbons along the [01 ] direction, which are stabilized via Cl?Cl [3.2916 (3) Å] contacts. The ribbons are stacked via C?O contacts [3.2367 (12)-3.3948 (12) Å].Item Redetermination of methyl 3,4-O-isopropyl-idene-?-D-fucopyran-oside monohydrate(2009) Fun, H.-K.; Jebas, S.R.; Rai, S.; Shetty, P.; Isloor, A.M.In the title compound, C10H18O5· H2O, the fucopyran-oside ring adopts a chair conformation. The crystal packing is stabilized by inter-molecular O - H?O and C - H?O hydrogen bonds together with intra-molecular O?O [2.2936 (8) Å] and inter-molecular O?O [2.7140 (8)-2.829 (3) Å] short contacts. The mol-ecules are linked together to form an infinite chain along the a axis. This structure has been solved previously but with no R-values [Spiers (1931). Z. Kristallogr. Kristallgeom. Kristallphys. Kristallchem. 78, 101].