Rizwan Ullah

Dr. Rizwan Ullah


Research Focus & Metrics

Academic Career Length

13Years (2014-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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7 January 2022 in Polymers
Verified
Journal Article
Open access
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RURizwan Ullah
Rizwan Ullah
NKNadia Khan
Nadia Khan
RKRozina Khattak
Rozina Khattak
Mehtab KhanMehtab Khan
Mehtab Khan
MKMuhammad Khan
Muhammad Khan
OAOmae M. Ahmed
Omae M. Ahmed
The current research focused on the super capacitive behavior of organic conducting polymer, i.e., polypyrrole (PPy) and its composites with gum arabic (GA) prepared via inverse emulsion polymerization. The synthesized composites material was analyzed by different analytical techniques, such as UV-visible, FTIR, TGA, XRD, and SEM. The UV-Vis and FTIR spectroscopy clearly show the successful insertion of GA into PPy matrix. The TGA analysis shows high thermal stability for composites than pure PPy. The XRD and SEM analysis show the crystalline and amorphous structures and overall morphology of the composites is more compact and mesoporous as compared to the pure PPy. The electrochemical properties of modified solid state supercapacitors established on pure polypyrrole (PPy), polypyrrole/gum arabic (PPy/GA) based composites were investigated through cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and galvanostatic charge–discharge (GCD). The specific capacitance of the PPy modified gold electrode is impressive (~168 F/g). The specific capacitance of PPy/GA 1 electrode has been increased to 368 F/g with a high energy density and power density (~73 Wh/kg), and (~599 W/kg) respectively.

6 October 2021 in Nanomaterials
Verified
Journal Article
Open access
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RQRaina Aman Qazi
Raina Aman Qazi
RKRozina Khattak
Rozina Khattak
LSluqman shah
luqman shah
RURizwan Ullah
Rizwan Ullah
MKMuhammad Khan
Muhammad Khan
ZEZeinhom M. ElBahy
Zeinhom M. ElBahy
Partially biodegradable polymer nanocomposites Poly(3-Hydroxybutyrate) (PHB)/MultiwalledCarbon Nanotubes (MWCNTs)/Poly(Methyl Methacrylate) (PMMA)and non-biodegradable nanocomposites (MWCNTs/PMMA) were synthesized, and their thermal, electrical, and ammonia-sensing properties were compared. MWCNTs were chemically modified to ensure effective dispersion in the polymeric matrix. Pristine MWCNTs (p-MWCNTs) were functionalized with –COOH (a-MWCNTs) and amine groups (f-MWCNTs). Then, PHB grafted multiwalled carbon nanotubes (g-MWNTs) were prepared by a ‘grafting to’ technique. The p-MWCNTs, a-MWCNTs, f-MWCNTs, and g-MWCNTs were incorporated into the PMMA matrix and PMMA/PHB blend system by solution mixing. The PHB/f-MWCNTs/PMMA blend system showed good thermal properties among all synthesized nanocomposites. Results from TGA and dTGA analysis for PHB/f-MWCNTs/PMMA showed delay in T5 (about 127 °C), T50 (up to 126 °C), and Tmax (up to 65 °C) as compared to neat PMMA. Higher values of frequency capacitance were observed in nanocomposites containing f-MWCNTs and g-MWCNTs as compared to nanocomposites containing p-MWCNTs and a-MWCNTs. This may be attributed to their excellent interaction and good dispersion in the polymeric blend. Analysis of ammonia gas-sensing data showed that PHB/g-MWCNTs/PMMA nanocomposites exhibited good sensitivity (≈100%) and excellent repeatability with a constant response. The calculated limit of detection (LOD) is 0.129 ppm for PHB/g-MWCNTs/PMMA, while that of all other nanocomposites is above 40 ppm.

28 February 2023 in Separations
Verified
Journal Article
Open access
PDF file
SGSalma Gul
Salma Gul
SGShehla Gul
Shehla Gul
HGHajera Gul
Hajera Gul
FKFatima Khitab
Fatima Khitab
RKRozina Khattak
Rozina Khattak
Ivar ZekkerIvar Zekker
Ivar Zekker
The dyeing industry uses many chemicals and dyes. After the dying process is completed, they release a significant amount of dyes in wastewater. The dyes’ color emissions are extremely poisonous and dangerous for aquatic and terrestrial life. Due to the toxic nature of dyes, the current study was carried out to evaluate whether it would be effective to employ an adsorption procedure with leaves from the Adiantum capillus-veneris plant as an adsorbent to remove commonly used textile dyes from an aqueous dye solution and wastewater. The effect of pH, concentration, time and the adsorbent dose on the adsorption process was studied in order to determine the maximum adsorption under ideal conditions. The selected pH was 3; the optimum concentration was 30 ppm with a contact time of 90 min and the optimized adsorbent dose was 60 mg. The absorbent under study showed excellent results when compared with commercial adsorbents i.e., animal charcoal and silica gel. The leaves of the Adiantum capillus-veneris plant revealed a maximum removal of 90.36 percent crystal violet dye (adsorption capacity (Qe) 9.05 mg/g) without any treatment to activate or alter the surface chemistry of the biosorbent. Its effectiveness was also tested with water gathered from several sources, including canal water, tap water, distilled water, and saline water, to determine whether it was practical. In both the canal and the tap water, the adsorbent displayed good removal efficiency. From the results of the current study, it can be inferred that the leaves of the Adiantum capillus-veneris plant are a reasonably priced biosorbent that can be used to remove toxic dyes from wastewater to protect water bodies from toxic pollution and can be used to treat industrial wastewater directly.

14 September 2018 in Advances in Polymer Technology
Verified
Journal Article
Closed access
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RURizwan Ullah
Rizwan Ullah
SBSalma Bilal
Salma Bilal
ASAnwar‐Ul‐Haq Ali Shah
Anwar‐Ul‐Haq Ali Shah
GRGul Rahman
Gul Rahman
KAKhurshid Ali
Khurshid Ali

1 November 2021 in Materials Chemistry and Physics
Verified
Journal Article
Closed access
RURizwan Ullah
Rizwan Ullah
SYSobia Yaseen
Sobia Yaseen
ASAnwar-Ul-Haq Ali Shah
Anwar-Ul-Haq Ali Shah
SBSalma Bilal
Salma Bilal
MKMuhammad Kamran
Muhammad Kamran
MRMaheen Rahim
Maheen Rahim

29 August 2024 in Electrochimica Acta
Verified
Journal Article
Closed access
NKNadia Khan
Nadia Khan
RURizwan Ullah
Rizwan Ullah
MKMehtab Khan
Mehtab Khan
ALAlmas
Almas