Dipak Rana

Bio: Dipak Rana is an academic researcher from University of Ottawa. The author has contributed to research in topics: Membrane & Contact angle. The author has an hindex of 54, co-authored 270 publications receiving 9283 citations.

Insight Studies on Metal-Organic Framework Nanofibrous Membrane Adsorption and Activation for Heavy Metal Ions Removal from Aqueous Solution.

Abstract: Electrospun nanofiber composite membranes containing water-stable metal-organic frameworks (MOFs) particles (Zr-based MOF-808) supported on polyacrylonitrile (PAN) nanofiber synthesized via co-electrospinning have been prepared. MOF particles were dispersed in the organic polymer, and their subsequent presence was inferred by scanning electron microscopy. Membrane performance in heavy metal ion adsorption in batch filtration was evaluated on the basis of Cd2+ and Zn2+ ions sequestration. The adsorption capacities of the pristine MOF and the MOF composite membrane revealed that MOF particles in the membrane could be accessed for adsorption in the hydrophilic PAN membranes. The maximum adsorption capacities were 225.05 and 287.06 mg g–1 for Cd2+ and Zn2+, respectively. Conventional thermal activation of pristine MOF and composite membrane revealed a crystal downsizing, while “hydractivation” produced an expanded MOF with enhanced adsorption potentials. The PAN/MOF-808 “hydractivated” composite membrane coul...

Metal–organic frameworks supported on nanofibers to remove heavy metals

Abstract: Fe(III) and Zr(IV) based metal–organic frameworks (MOFs) were enmeshed in polyacrylonitrile (PAN) and polyvinylidene fluoride (PVDF) electro-spun nanofibers to produce nanofibrous MOF membranes (NMOM) The pristine MOFs showed high adsorption capacity for lead ions and mercury ions from aqueous solution The Fe(III) based MOFs with PAN based NMOM exhibited a high flux of 348 L m−2 h−1 with a permeance of 870 L m−1 h−1 bar−1 At room temperature, the NMOM could treat 395 mL of 100 ppb Pb(II) solution, while maintaining a drinking water standard of <10 ppb of permeate Pb(II) concentration Due to the high compatibility between MOF and PVDF nanofibers, MOF was not detected in the permeate even after four cycles of filtration and desorption experiments and more than 90% of the NMM adsorption capacity was retained The excellent filtration performance and re-generability of the membrane coupled with the hydro-stability of the MOFs suggests that the NMOMs have potential for water treatment through the process of membrane adsorption

Electrospinning and Electrospun Nanofibers: Methods, Materials, and Applications

Abstract: Electrospinning is a versatile and viable technique for generating ultrathin fibers. Remarkable progress has been made with regard to the development of electrospinning methods and engineering of electrospun nanofibers to suit or enable various applications. We aim to provide a comprehensive overview of electrospinning, including the principle, methods, materials, and applications. We begin with a brief introduction to the early history of electrospinning, followed by discussion of its principle and typical apparatus. We then discuss its renaissance over the past two decades as a powerful technology for the production of nanofibers with diversified compositions, structures, and properties. Afterward, we discuss the applications of electrospun nanofibers, including their use as "smart" mats, filtration membranes, catalytic supports, energy harvesting/conversion/storage components, and photonic and electronic devices, as well as biomedical scaffolds. We highlight the most relevant and recent advances related to the applications of electrospun nanofibers by focusing on the most representative examples. We also offer perspectives on the challenges, opportunities, and new directions for future development. At the end, we discuss approaches to the scale-up production of electrospun nanofibers and briefly discuss various types of commercial products based on electrospun nanofibers that have found widespread use in our everyday life.