Current Research Focus:
Nanofiber Based Functional Membranes for Water Remediation
In Pakistan, various investigations and surveys have indicated that water quality has significantly deteriorated and is a major cause of many health related issues. Unchecked disposal of municipal and industrial effluent, poor solid waste management, use of hazardous chemicals, vehicles emissions and industrial activity has contributed to a number of health and environmental hazards, chief among those being water pollution.
Our focus is on developing materials physics and chemistry based strategies for efficient bacterial and viral removal from water. Electrospinning is a simple, rapid, low cost, and technologically scalable technique for making long and continuous nanofibers in non-woven form which can be utilized to obtain nanofiber based filter membranes that can separate nanoscale species in the water.
We are working on the development of a low cost yet scalable, robust, sustainable, and self-cleaning/anti-fouling filters for cleaning the biological contaminants from water. The unique aspect of this proposed project involves modifying the electrospinning process such the nanofibers of relevant polymer or polymer blends are surface functionalized with tailored bandgap oxide nanoparticles which have both visible light photocatalytic and antimicrobial properties.
Porous Carbon Nanofibers for Enhanced Electrochemical Performance
One-dimensional (1D) nanomaterials have gained much attention for their usage in electrochemical energy conversion and storage devices as electrode materials due to their large surface area and great potential for tuning their interfacial properties. Carbon materials prove to be potential candidates for this purpose because of their high chemical and thermal stability, great conductivity and relatively low cost. Enhanced surface area in case of porous carbon materials further adds to their electrochemical behaviour. Focus of this work is to get enhanced electrochemical performance by optimizing the pore characteristics in porous carbon nanofiber (CNF) composites.
Lithium ion batteries (LIBs) possess long cycle life, high energy density, thermal stability, less self-discharge and higher storage ability than its competitors such as nickel-metal hydride and lead acid batteries. After the development of first lithium battery in 1970s, a great deal of improvement and innovation has led to modern commercial LIBs which consist of LiCoO2 as cathode and graphite as anode. However, demand for increased energy and power density requires innovative solutions for new electrode materials/architectures with higher capacities and longer life. Silicon is a very promising candidate due to large theoretical capacity of 4200 mAhg-1. But Si undergoes large volume deviations during charging/discharging making it prone to structural failure. Improvement of the cyclability of Si has been the focus of many studies by using Si decorated CNTs, Si nanowires, and C-Si core-shell nanowires. This project focuses on using both C and Si as a composite solution for improved electrochemical performance in batteries by maintaining structural integrity and electrical conductivity.
Surface Modulated Carbon Nanofibers for Composites
Nanotechnology offers unique opportunities to develop novel material combinations, known as nano-composites, which potentially can bypass typical material performance trade-offs. At nanometer length scales, the significantly higher interfacial area between phases become dominant in determining the overall performance. Carbon nanofibers (CNF) derived from polyacrylonitrile (PAN) by electrospinning has many advantages such as being long, continuous, and in aligned form. They can be incorporated in polymer matrix composites for matrix strengthening and toughening. Moreover, these carbon nanofibers in polymer nanocomposites can show enhanced toughening if the nanofiber surfaces have slight undulations resulting in stronger adhesion.
Theoretical models have been developed which suggests that the fracture toughness of a propagating crack can be enhanced due to crack tip shielding due to interface undulations. This has not been investigated experimentally mainly due to difficulty in synthesizing such materials and limitations in nanoscale testing. Dr. Arshad has patented a process in which PAN nanofibers can be fabricated with periodic surface ripples. These kind of PAN nanofibers provide an ideal precursor material for making carbon nanofibers with modulated (rippled) surfaces. The goal of this project is to develop nanocomposite materials with surface modulated carbon nanofibers for unprecedented enhancement in strengthening and toughening.
Higher Education Commission (NRPU)
LUMS Start-up grant
LUMS Faculty Initiative Fund