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1
Content available remote Innovations in poly(vinyl alcohol) derived nanomaterials
100%
Kausar A.
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tom Vol. 20, nr 3(65)
5--22
EN
Poly(vinyl alcohol) (PVA) has been considered as an important commercial synthetic thermoplastic polymer. PVA is a low cost, reasonably processable, optically transmitting, heat stable, and mechanically robust plastic. PVA-based nanomaterials usually comprise of the nanocomposites (PVA/graphene, PVA/carbon nanotube, PVA/nanodiamond, PVA/metal nanoparticle) and nanofibers. The structural, optical, mechanical, and electrical properties of the PVA-based nanomaterials have been enhanced with nanofiller addition or nanostructuring. This review offers fundamentals and advanced aspects of poly(vinyl alcohol) and the derived nanomaterials. It highlights recent advances in PVA nanocomposites and nanofibers for potential applications. The PVA-based nanomaterials have been successfully employed in fuel cells, sensors, batteries, membranes, electronics, and drug delivery relevances. The challenges and opportunities to strengthen the research fields of PVA-based nanomaterials have also been presented.
2
Content available remote Effect of nanofiller dispersion on morphology, mechanical and conducting properties of electroactive shape memory Poly(urethane-urea)/functional nanodiamond composite
100%
Kausar A.
Advances in Materials Science
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2015
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tom Vol. 15, nr 4(46)
14--28
EN
In this attempt, segmented poly(urethane urea) was prepared from polycaprolactone triol (soft segment), 1,3- bis(isocyanatomethyl)cyclohexane (hard segment) and 4,5-diaminophthalonitrile (chain extender). Acidfunctionalized nano-diamond was used as nano-filler. The nanocomposites were processed using solution casting and melt blending. Unique morphology was observed by SEM due to generation of crosslinked polyurethane and ND network. The s-PUU/ND 10 depicted 6 % increase in tensile strength compared with m-PUU/ND 10. 10 wt. % ND loading via solution route increased conductivity to 0.089 Scm-1 relative to m-PUU/ND 10 (0.057 Scm-1). Electrical conductivity of nanocomposites was enough to show electroactive shape recovery of 95 % (40 V).
3
Content available remote Polycarbonate/Polypropylene-Graft-Maleic Anhydride and Nano-Zeolite-Based Nanocomposite Membrane: Mechanical and Gas Separation Performance
100%
Kausar A.
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tom Vol. 16, nr 4(50)
17--28
EN
In this effort, blend membrane of polycarbonate (PC) and polypropylene-graft-maleic anhydride (PPMA) was fabricated via phase inversion technique. The nano-zeolite (NZ) was employed as nanofiller. Morphology of PC/PPMA/NZ membrane revealed unique inter-connected branched microstructure. Tensile strength and Young’s Modulus of PC/PPMA/NZ 0.1-5 were in the range of 59.9-74.5 MPa and 111.4-155.2 MPa respectively. The nano-zeolite filler was also effective in enhancing the permselectivity αCO2/N2 (23.5 to 38.5) relative to blend membrane (20.3). The permeability PCO2 of PC/PPMA/NZ 5 membrane was found as 106.2 Barrer. Filler loading enhanced gas diffusivity, however filler content did not significantly influence CO2 and N2 solubility.
4
Content available remote Polyamide 1010/Polythioamide Blend Reinforced with Graphene Nanoplatelet for Automotive Part Application
100%
Kausar A.
Advances in Materials Science
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2017
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tom Vol. 17, nr 3(53)
24--36
EN
Novel polythioamide (PTA) was prepared and blended with polyamide 1010 (PA1010). Based on morphology, molecular weight, polydispersity index, thermal, and shear stress behavior, PA1010/PTA (90:10) blend was opted as matrix for graphene nanoplatelet (GNP) reinforcement. Inclusion of functional GNP resulted in crumpled gyroid morphology. T0 (502°C) of PA1010/PTA/GNP was increased by 145°C than unfilled blend (357°C). Limiting oxygen index measurement indicated better non-flammability of PA1010/PTA/GNP1-3 nanocomposites (53-55%) relative to PA1010/PTA1-3 (41-48%). PA1010/PTA/GNP1-3 also attained V-0 rating in UL94. Furthermore, PA1010/PTA/GNP3 nanocomposite revealed optimum tensile strength (40 MPa), impact strength (1.9 MPa), and flexural modulus (1373 MPa) to manufacture automotive part.
5
Content available remote Advances in carbon fiber reinforced polyamide-based composite materials
100%
Kausar A.
Advances in Materials Science
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2019
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tom Vol. 19, nr 4(62)
67--82
EN
Carbon fiber has been used to reinforce both aliphatic and aromatic polyamides. Aliphatic polyamide is known as nylon and aromatic polyamide is often referred to as aramid. Among aliphatic polyamides, polyamide 6, polyamide 6,6, polyamide 11, polyamide 12, and polyamide 1010 have been used as matrices for carbon fiber. Factors affecting the properties of polyamide/carbon fiber composites are: fiber amount, fiber length, fiber orientation, matrix viscosity, matrix-fiber interactions, matrix-fiber adhesion, and conditions encountered during manufacturing processes. This article presents a state-of-the-art review on polyamide/carbon fiber composites. Polyamide/carbon fiber composites are lightweight and exhibit high strength, modulus, fatigue resistance, wear resistance, corrosion resistance, gear, electrical conductivity, thermal conductivity, chemical inertness, and thermal stability. Incorporation of oxidized or modified carbon fiber and nanoparticle modified carbon fiber into polyamide matrices have been found to further enhance their physical properties. Applications of polyamide/carbon fiber composites in aerospace, automobile, construction, and other industries have been stated in this review. To fully exploit potential of polyamide/carbon fiber composites, concentrated future attempts are needed in this field.
6
Content available remote Novel mechanically stable, heat resistant and nonflammable functionalized polystyrene/expanded graphite nanocomposites
51%
Kausar A. , Ullah W. , Muhammad B. , Siddiq M.
Advances in Materials Science
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2014
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tom Vol. 14, nr 4(42)
61--74
EN
This study examined effect of inclusion of expanded graphite (Exp-G) on morphology, thermal, mechanical and flame retardant properties of PS, nitro-substituted polystyrene (N-PS) and amino-functional polystyrene (A-PS). FESEM showed exfoliated sheet morphology due to intercalation of N-PS and A-PS in expanded galleries. Tensile strength of A-PS materials (31.5-56.9 MPa) was higher than PS and N-PS. 10 % weight loss of A-PS nanocomposites (482-518 °C) was higher relative to pristine polymer and other nanocomposites. Cone calorimetry results revealed that there was lowering in PHHR of A-PS nanocomposites with 0.5 wt.% filler (428 kW/m2), while PS nanocomposites showed PHHR of 443 kW/m2.
7
Redox mediators assisted-degradation of direct yellow 4
32%
Nouren S. , Bhatti H. N. , Iqbal M. , Bibi I. , Nazar N. , Iqbat D. N. , Kanwal Q. , Kausar A. , Hussain F.
Polish Journal of Environmental Studies
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2017
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tom 26
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nr 6
EN
Direct yellow 4 degradation was investigated in the presence of various mediators (p-coumaric acid, 1, hydroxybenzotriazole (HOBT), syringaldehyde, vanillin, syringic acid, veratryl alcohol, and pyrocatechol) at pre-optimized conditions of process variables, i.e., pH 5.0, temperature 50ºC, enzyme dose 24 U/mL, and 0.25 mM H₂O₂ concentration. Citrus limon peroxidase (CL-POD) was used for degradation of DY4 dye. In the absence of mediators, the DY4 degradation was 60%, whereas mediators enhanced the POD biodegradation efficiency up to 87%. Among mediators investigated, syringaldehyde showed promising efficiency. We investigated yringaldehyde concentrations in the range of 0.0125-0.5 mM, and 0.025 mM was optimum for maximum dye degradation, which revealed that mediators could be used to enhance the biodegradation of dyes.
8
Sweet lime-mediated decolorization of textile industry effluen
26%
Nouren S. , Sarwar M. , Muhi-ud-Din G. , Yameen M. , Bhatti H. N. , Soomro G. A. , Suleman N. , Bibi I. , Kausar A. , Nazir A. , Iqbal M.
Polish Journal of Environmental Studies
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2019
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tom 28
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nr 1
EN
This study looks at using partially purified peroxidase extracted from peels of sweet lime (Citrus limetta) for decolorizing textile industry effluent. The ideal pH and thermal conditions of the enzyme were 7 and 35ºC. The Km and Vmax for guaiacol were 0.66 mM and 6666 μmol/mL/min, respectively. We found that sweet lime peroxidase was very effective in decolorizing textile industry effluent. Almost complete decolorization (>99 %) of effluent was attained at a pH of 5.0, temperature of 55ºC, H₂O₂ concentration of 2 mM, and enzyme dose of 40 U/mL within 60 minutes of incubation. The effluent was also analysed in terms of physicochemical parameters before and after treatment with sweet lime peroxidase. The reduction in toxicity after the enzymatic treatment was evidenced by chemical oxygen demand (COD) and total suspended solids (TSS) values.
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