Mohammad Rezaul Karim | King Saud University (original) (raw)

Papers by Mohammad Rezaul Karim

Applied Surface Science, 2024

The aqueous zinc-ion battery's (AZBs) inherent safety and inexpensive cost make it an attractive ... more The aqueous zinc-ion battery's (AZBs) inherent safety and inexpensive cost make it an attractive prospect for next-generation energy storage. Nevertheless, AZBs are presently troubled by the formation of Zn dendrites and unwanted side-reactions, which can lead to cycling instability and premature collapse. This study demonstrates the fabrication of an N-doped polyacrylonitrile (PAN) carbon fiber (PCF) network with ionic conductivity using the electrospinning of a PAN solution followed by thermal treatment. Zn plating and stripping behavior can be controlled by using a three-dimensional PCF with a polar functional group as an interlayer covering on the zinc anode. This allows for partially deposited zinc to be accommodated, which ultimately results in zinc dendritefree deposition on the zinc anode. This phenomenon is initially proven in Zn@PCF symmetric cells, and then it is demonstrated further in Zn@PCF/MnO 2 whole cells, where the dendritic Zn anode surfaces become completely smooth and devoid of any features. This results in a charging and discharging cycle that is far longer than one would normally experience. The findings of this study offer a viable path toward the development of dendrite-free AZBs with great performance.

Current Nanoscience, Mar 3, 2016

Carbohydrate Polymers, Sep 1, 2009

Pullulan (PULL)/montmorillonite clay (MMT) nanofiber blend mats with various weight ratios have b... more Pullulan (PULL)/montmorillonite clay (MMT) nanofiber blend mats with various weight ratios have been fabricated by the electrospinning technique in aqueous solution. The PULL/MMT nanofiber mats are characterized by X-ray diffraction (XRD), differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA), field-emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), Fourier transform infrared (FT-IR) and mechanical measurements. The study shows that the introduction of MMT results in improvement in tensile strength, and thermal stability of the PULL matrix. XRD patterns and TEM micrographs suggest the coexistence of intercalated MMT layers over the studied MMT contents. XRD analyses also reveal an increase of the crystallinity of the blend nanofiber mats with addition of MMT fillers. Moreover, FT-IR divulges that there might be possible interaction occurred between the MMT clay and PULL matrix.

Polymers, Sep 19, 2022

This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY

Polymers & Polymer Composites, Nov 1, 2011

Nanofibre mats of poly(vinyl alcohol) (PVA), waterborne polyurethane (WBPU) and nanometre silver ... more Nanofibre mats of poly(vinyl alcohol) (PVA), waterborne polyurethane (WBPU) and nanometre silver (Ag) colloids have been fabricated by an electrospinning method in aqueous solutions. Since PVA is a water soluble and biocompatible polymer, it is one of the best materials for preparation of electrospun antibacterial nanofibre mats. WBPU was used as a filler to enhance the properties of homopolymer nanofibre. Transmission electron microscopy analyses showed a uniform distribution of silver in the fibres. In anti-bacterial tests, the PVA/ WBPU/Ag composite nanofibres showed excellent anti-bacterial performance, indicating practical uses as a new preservative. Moreover, the PVA/WBPU/Ag nanofibres showed improved thermal properties.

ACS Applied Polymer Materials, 2019

Here, we report the synthesis of a bimetallic supramolecular polymer (SMP) for fabricating an ele... more Here, we report the synthesis of a bimetallic supramolecular polymer (SMP) for fabricating an electrochemical nitrite sensor and study the reaction mechanism of the selective oxidation of nitrite by cyclic voltammetry (CV) simulation through the kinetic parameters evaluation. Symmetrical ligand-bearing terpyridine moieties [4′,4′′′′-(1,4-Phenylene)bis(2,2′:6′,2′′terpyridine)] were complexed with Ni(II), and Co(II) salts (Co:Ni:Ligand-0.5:0.5:1) (polyNiCo) to synthesize a heterometallo-SMP. The polyNiCo was characterized by using UV/Vis spectrophotometric titration, SEM, EDS, FT-IR, EIS, and CV techniques. The molecular weight of the polymer was determined from the intrinsic viscosity measurement using the Mark-Houwink-Sakurada equation. While the spectroscopic data revealed the structural morphologies and properties of the polyNiCo, electroanalytical characterization studies confirmed the high electrochemical activity and suitability of the polyNiCo heterometallo-SMP as an electrochemical sensor. A glassy carbon electrode (GCE) was used as the base for fabricating ployNiCo_GCE and also for detecting the nitrite analyte through the oxidation process. The kinetics for the irreversible oxidation mechanism were studied using scan-rate and pH-variation methods. The electroactive surface area, electron transfer coefficient, heterogeneous electron transfer rate constant, etc. parameters were studied using the Butler-Volmer equations. We simulated the CV for the nitrite oxidation process at the polyNiCo_GCE based on the analysis of the kinetic parameters obtained from the electroanalytical experiments. An exceptional agreement between the experimental and simulated CV was found, which confirmed the validity of the calculated kinetic parameters. Using CV and amperometry techniques, we studied the effectiveness of the polyNiCo_GCE for detecting the nitrite analyte at different concentrations. The amperometry technique showed a wide linear range of 2.5 μM-1.73 mM and a limit of detection (LOD) of 0.45 μM. The sensor was also tested for interference, stability, and reproducibility. Real sample analysis was performed using both CV and amperometry techniques, and the obtained results were compared with the results obtained by using standard solutions.

Journal of Applied Polymer Science, Aug 5, 2009

Poly(vinyl alcohol) (PVA)/montmorillonite clay (MMT) nanofiber mats have been fabricated by the e... more Poly(vinyl alcohol) (PVA)/montmorillonite clay (MMT) nanofiber mats have been fabricated by the electrospinning technique. The PVA/MMT nanofiber mats were characterized by X-ray diffraction (XRD), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), Fourier transform infrared (FTIR), and mechanical measurements. The study showed that the introduction of MMT results in improvement in tensile strength, and thermal stability of the PVA matrix. XRD patterns and SEM micrographs suggest the coexistence of exfoliated MMT layers over the studied MMT contents. FTIR revealed that there might be possible interaction occurred between the MMT clay and PVA matrix. V

Polymers

A perfect protective fabric for handicapped individuals must be lightweight, waterproof, breathab... more A perfect protective fabric for handicapped individuals must be lightweight, waterproof, breathable, and able to absorb water. We present a multifunctional protective fabric in which one side is hydrophobic based on the intrinsic hydrophobic biopolymer polylactic acid (PLA) to keep the disabled person from getting wet, while the other side is super-hydrophilic due to embedded silica nanoparticles (NPs) to keep the disabled person safe from a sudden spill of water or other beverage on their skin or clothes. The porosity of the electrospun nanofibrous structure allows the fabric to be breathable, and the silica NPs play an important role as a perfect infrared reflector to keep the person’s clothing cool on warm days. Adding white NPs, such as silicon dioxide, onto or into the textile fibers is an effective method for producing thermally insulated materials. Due to their ability to efficiently block UV light, NPs in a network keep the body cool. Such a multifunctional fabric might be i...

Energy Procedia, 2012

Zinc oxide (ZnO) thin films were deposited by RF magnetron sputtering onto ITO coated soda-lime g... more Zinc oxide (ZnO) thin films were deposited by RF magnetron sputtering onto ITO coated soda-lime glass substrates. The effects of annealing in temperature range of 250 to 450°C on the structural and optical properties of the ZnO films have been studied. The crystalline structure, surface topology, morphology, optical properties of the films were determined using X-ray diffraction (XRD), atomic force microscopy (AFM), scanning electron microscopy (SEM) and UV-Visible Spectrometry, respectively. X-ray diffraction measurement showed that the annealed ZnO films were polycrystalline in nature with (002), (101) and (001) oriented crystallites of hexagonal wurtzite structure. Crystalline property and grain size of the films were found to increase after annealing. The optical band gap of ZnO films initially blue shifted (3.1-3.23 eV) when annealed at 400°C and further red shifted in the range of 3.23 to 3.1 eV being annealed at 250 to 450°C range. From the UV spectroscopy, the films showed transmittance over 85% in the optical bandgap spectrum. All these results indicate that post deposition annealing improves the film quality with reduced roughness and better crystalline properties that can be utilised as buffer layer in the CIGS or CdTe thin film solar cells.

ABSTRACT The structural and optical properties of annealed CdS are studied in this work. The CdS ... more ABSTRACT The structural and optical properties of annealed CdS are studied in this work. The CdS films are deposited on ITO coated glasses by sputtering at different substrate temperatures and subsequently annealed in an O2/N2 ambient. It has been observed from XRD diffraction that the films show a trend of conversion from poly crystalline to amorphous or mixed phases after annealing. The films fabricated at room temperature (RT) have been found in complete amorphous form. The surface roughness of the films drastically increased due to thermal annealing observed from AFM images. Optical properties of the films were observed using UV-Vis spectrometer and band gaps of the films were found in the range of 2.80 to 3.08 eV. The annealed films exhibited the blue shift in the direct allowed transition energy band gaps, possibly due to the oxygen incorporation during annealing suggesting the transformation to CdS:O films.

Biosensors

Over the past several years, wearable electrophysiological sensors with stretchability have recei... more Over the past several years, wearable electrophysiological sensors with stretchability have received significant research attention because of their capability to continuously monitor electrophysiological signals from the human body with minimal body motion artifacts, long-term tracking, and comfort for real-time health monitoring. Among the four different sensors, i.e., piezoresistive, piezoelectric, iontronic, and capacitive, capacitive sensors are the most advantageous owing to their reusability, high durability, device sterilization ability, and minimum leakage currents between the electrode and the body to reduce the health risk arising from any short circuit. This review focuses on the development of wearable, flexible capacitive sensors for monitoring electrophysiological conditions, including the electrode materials and configuration, the sensing mechanisms, and the fabrication strategies. In addition, several design strategies of flexible/stretchable electrodes, body-to-ele...

RSC Advances, 2021

In this study, gel polymer electrolytes (GPEs) were prepared using polyacrylonitrile (PAN) polyme... more In this study, gel polymer electrolytes (GPEs) were prepared using polyacrylonitrile (PAN) polymer, ethylene carbonate (EC), propylene carbonate (PC) plasticizers and different compositions of tetrapropylammonium iodide (TPAI) salt.

RSC Advances, 2020

The conjugated conducting polyaniline was fabricated onto PANI-TiO2 nanoparticles prepared by mic... more The conjugated conducting polyaniline was fabricated onto PANI-TiO2 nanoparticles prepared by microwave-accelerated reaction system for the development an efficient and sensitive electrochemical sensor to protect the environment and healthcare fields in a broad scale.

ACS Omega, 2020

Here, we report a semiempirical quantum chemistry computational approach to understanding the ele... more Here, we report a semiempirical quantum chemistry computational approach to understanding the electrocatalytic reaction mechanism (ERM) of a metallic supramolecular polymer (SMP) with nitrite through UV/vis spectral simulations of SMP with different metal oxidation states before and after interactions with nitrite. In one of our recent works, by analyzing the electrochemical experimental data, we showed that computational cyclic voltammetry simulation (CCVS) can be used to predict the possible ERM of heterometallo-SMP (HMSMP) during electrochemical oxidation of nitrite (Islam, T.et al.ACS Appl. Polym. Mater. 2020, 2(2), 273−284). However, CCVS cannot predict how the ERM happens at the molecular level. Thus, in this work, we simulated the interactions between the repeating unit (RU) of the HMSMP polyNiCo and nitrite to understand how the oxidation process took place at the molecular level. The RU for studying the ERM was confirmed through comparing the simulated UV/vis and IR spectra with the experimental spectra. Then, the simulations between the RU of the polyNiCo and various species of nitrite were done for gaining insights into the ERM. The simulations revealed that the first electron transfer (ET) occurred through coordination of NO 2 − with either of the metal centers during the two-electron-transfer oxidation of nitrite, while the second ET followed a ligand−ligand charge transfer (LLCT) and metal−ligand charge transfer (MLCT) pathway between the NO 2 species and the RU. This ET pathway has been proposed by analyzing the transition states (TSs), simulated UV/vis spectra, energy of the optimized systems, and highest occupied molecular orbital−lowest occupied molecular orbital (HOMO−LUMO) interactions from the simulations between the RU and nitrite species.

International Journal of Molecular Sciences, 2018

Low availability of inorganic phosphate (Pi), together with aluminum (Al), is a major constraint ... more Low availability of inorganic phosphate (Pi), together with aluminum (Al), is a major constraint for plant growth and development in acidic soils. To investigate whether or not Al-resistant cultivars can perform better under Pi deficiency, we chose two wheat cultivars with different Al-responses—Atlas 66, being Al-tolerant, and Scout 66, which is Al-sensitive—and analyzed their responses to Pi deficiency. Results showed that, unexpectedly, the Al-sensitive cultivar Scout 66 contained comparatively higher amount of soluble phosphate (Pi) and total phosphorus (P) both in the roots and in the shoots than Atlas 66 under P deficiency. In addition, Scout 66 exhibited higher root biomass, root volume, and root tip numbers, compared with Atlas 66. The expression of Pi-responsive marker genes, TaIPS1, TaSPX3, and TaSQD2 was strongly induced in both cultivars, but the extents of induction were higher in Scout 66 than in Atlas 66 under long-term Pi starvation. Taken together, our results sugge...

Optical and Quantum Electronics, 2020

Modeling of dispersion-engineered all-chalcogenide step-index fiber for wideband supercontinuum g... more Modeling of dispersion-engineered all-chalcogenide step-index fiber for wideband supercontinuum generation in the midinfrared. Optical and Quantum Electronics, 52(5), 243..

International Journal of Molecular Sciences, 2020

Nitrogen deficiency usually occurs along with aluminum toxicity in acidic soil, which is one of t... more Nitrogen deficiency usually occurs along with aluminum toxicity in acidic soil, which is one of the major constraints for wheat production worldwide. In order to compare adaptive processes to N deficiency with different Al-tolerant wheat cultivars, we chose Atlas 66 and Scout 66 to comprehensively analyze the physiological responses to N deficiency, coupled with label-free mass spectrometry-based proteomics analysis. Results showed that both cultivars were comparable in most physiological indexes under N deficient conditions. However, the chlorophyll content in Scout 66 was higher than that of Atlas 66 under N deficiency. Further proteomic analysis identified 5592 and 5496 proteins in the leaves of Atlas 66 and Scout 66, respectively, of which 658 and 734 proteins were shown to significantly change in abundance upon N deficiency, respectively. The majority of the differentially expressed proteins were involved in cellular N compound metabolic process, photosynthesis, etc. Moreover, ...

Journal of Advanced Research, 2018

h i g h l i g h t s Influence of tin as a co-catalyst for nickel toward urea oxidation is propose... more h i g h l i g h t s Influence of tin as a co-catalyst for nickel toward urea oxidation is proposed. Tin co-catalyst shows very high current density; 175 mA/cm 2. The calcination temperature was optimized; 850°C is the best. The corresponding onset potential is 175 mV which indicates applicability in DUFC. Synthesis process is effective, simple and high yield technology; electrospinning.

In this investigation magnetic γ-Al2O3 ceramic nanocomposite particles bearing epoxide func... more In this investigation magnetic γ-Al2O3 ceramic nanocomposite particles bearing epoxide functionality are prepared following a multistep process. The ultimate nanocomposite particles are named as γ-Al2O3/Fe3O4/SiO2/poly(glycidyl methacrylate (PGMA). The surface property is evaluated by carrying out the adsorption study of Remazol navy (RN), a model reactive azo dye, on both γ-Al2O3/Fe3O4/SiO2 and γ-Al2O3/Fe3O4/SiO2/PGMA nanocomposite particles. The adsorption is carried out at the point of zero charge (PZC) to neutralize the effect of particle surface charge. The adsorption rate is very fast, reached equilibrium (qe) value within five min. Due to mesoporous structure of silica layer γ-Al2O3/Fe3O4/SiO2 nanocomposite particles possessed relatively higher specific surface area and magnitude of adsorption is dependent on the total specific surface area. The introduction of epoxide functionality favored high adsorption capacity in mass per unit surface area. ...