Saud Hashmi

Prof. Saud Hashmi

Chemical Engineering, NED University of Engineering and Technology, Karachi, Sindh, Pakistan
orcid

Research Focus & Metrics

Academic Career Length

15Years (2012-Present)

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

Representative Publications

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20 August 2013 in Polymer Chemistry
Verified
Journal Article
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MVMohammad Vatankhah-Varnoosfaderani
Mohammad Vatankhah-Varnoosfaderani
Saud HashmiSaud Hashmi
Saud Hashmi
ANAmin Ghavami Nejad
Amin Ghavami Nejad
Florian StadlerFlorian Stadler
Florian Stadler
Marine and freshwater mussels secrete proteinaceous adhesive materials for adherence to the substrates upon which they reside. It is well known that 3,4-dihydroxyphenylalanine (DOPA) is the key to understanding these mussel adhesive proteins (MAPs). In order to gain a better understanding of their complex formation and quick recovery upon rupturing, novel water soluble copolymers of N-isopropylacrylamide and dopamine methacrylate were synthesized in such a way that they have 1, 2.5, and 5 mole percent dopamine monomer with respect to the NIPAM monomer on average. The statistical distribution of DOPA-functionalities along the chain makes the material a close synthetic equivalent of the byssal thread proteins of mytili. At acidic pH, the aqueous copolymer solution behaves like an unentangled copolymer solution, but at basic pH, these catechol functionalities form a dicomplex with H3BO3, thereby crosslinking two chains, proven by 11B-NMR and gelation. The polymer solution is thermosensitive with a pH-dependent lower critical solution temperature (LCST) between 21 and 33 °C, depending on the DOPA-content. If 2 or more functionalities per chain are present, a gel is formed that is self-healing with very quick recovery from sustained damage. The moduli of the gels depend on the concentration of functionalities. Hence, triple stimuli responsive copolymers were obtained.

16 September 2014 in Macromolecular Rapid Communications
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Journal Article
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GKG. Gnana Kumar
G. Gnana Kumar
Saud HashmiSaud Hashmi
Saud Hashmi
CKChandrasekaran Karthikeyan
Chandrasekaran Karthikeyan
ANAmin Ghavami Nejad
Amin Ghavami Nejad
MVMohammad Vatankhah‐Varnoosfaderani
Mohammad Vatankhah‐Varnoosfaderani
Florian StadlerFlorian Stadler
Florian Stadler

2 August 2019 in ACS Sustainable Chemistry & Engineering
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Journal Article
Closed access
AZAwan Zahoor
Awan Zahoor
ZGZafar Khan Ghouri
Zafar Khan Ghouri
Saud HashmiSaud Hashmi
Saud Hashmi
FRFaizan Raza
Faizan Raza
SIShagufta Ishtiaque
Shagufta Ishtiaque
KNKee Suk Nahm
Kee Suk Nahm

18 March 2013 in Chemical Communications
Verified
Journal Article
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MVMohammad Vatankhah-Varnoosfaderani
Mohammad Vatankhah-Varnoosfaderani
ANAmin Ghavami Nejad
Amin Ghavami Nejad
Saud HashmiSaud Hashmi
Saud Hashmi
Florian StadlerFlorian Stadler
Florian Stadler
Novel covalent gels were prepared by complexation of polymer-bound catechols with NaBH4 at pH ≈ 9. These gels can absorb humidity, which changes the catechol–borate covalent bonds from irreversible to reversible. Furthermore, humidity induces self-healing, proven by rheological data.

4 December 2012 in Macromolecules
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Journal Article
Closed access
Saud HashmiSaud Hashmi
Saud Hashmi
ANAmin Ghavami Nejad
Amin Ghavami Nejad
FOFrancis O. Obiweluozor
Francis O. Obiweluozor
MVMohammad Vatankhah-Varnoosfaderani
Mohammad Vatankhah-Varnoosfaderani
Florian StadlerFlorian Stadler
Florian Stadler

24 November 2021 in Journal of Petroleum Exploration and Production Technology
Verified
Journal Article
Open access
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SLShaine Mohammadali Lalji
Shaine Mohammadali Lalji
SASyed Imran Ali
Syed Imran Ali
RARAFIQ AHMED
RAFIQ AHMED
Saud HashmiSaud Hashmi
Saud Hashmi
Zahoor ul Hussain AwanZahoor ul Hussain Awan
Zahoor ul Hussain Awan
Swelling of shale potentially occurs when it is exposed to water-based drilling fluid. The migration of hydrogen ions (H+) in the nano-interlayered platelets of the shale rock is utterly responsible for the swelling behavior in the shale. Conventionally, swelling behavior of any shale formation can be experimentally determined by linear dynamic swell meter. However, it is extremely important to validate these experimental results; hence, this research study aims in conducting a comparative performance analysis for different kinetic models, namely Peleg’s model, first-order exponential association equation and pseudo-second-order kinetic model, and a newly developed scaling swelling model in estimating the experimental results of three different shale samples, namely Talhar, Ranikot and Murree, obtained from different regions of Pakistan. It was found that the performance of the scaling swelling model was the most accurate in predicting the experimental swelling results with accuracy greater than 95% in all the three samples. Peleg’s model is found to be the most inaccurate with $$p \mathrm{values}< \alpha (0.05)$$ p values < α ( 0.05 ) in all the three formations. The equilibrium state in all the three samples was unable to attain by the use of this model. This clearly shows that the transient states continue throughout the course of experimentation, thus demonstrating a higher water activity in the shale samples. Moreover, when comparison was made between the two remaining kinetic adsorption models, it was perceived that pseudo-second-order kinetic was far superior to first-order exponential association equation with $${\mathrm{mean}}_{\mathrm{model}}\simeq {\mathrm{mean}}_{\mathrm{experiment}}$$ mean model ≃ mean experiment and less dispersion in the dataset. Nevertheless, the performance of this model also suffers with the increase in clay content. Furthermore, all these analyses were further validated by different statistical error analysis that includes MAE, APRE% and ANOVA.