Tahir Jamil - Academia.edu (original) (raw)

Papers by Tahir Jamil

Research paper thumbnail of Modification of cellulosic fabric using polyvinyl alcohol—PartI: Physicochemical properties

Carbohydrate Polymers

A series of poly(vinyl alcohol) of different commercial grades were prepared and applied onto the... more A series of poly(vinyl alcohol) of different commercial grades were prepared and applied onto the surfaces of cotton and blends of cotton/polyester fibers. The molecular structure was confirmed using Fourier Transform Infrared spectroscopy. Physicochemical properties such as viscosity and solid contents (%) were determined and discussed. Factors affecting the performance properties of the finished substrate such as post-treatment with poly(vinyl alcohol) of different grades, concentration and dilutions were studied. Fixation of the poly(vinyl alcohol) onto/or within the cellulose structure is accompanied by the formation of semi-inter-penetrated network structure thereby enhancing the association as well as providing very high stiffness. The results revealed that applications of poly(vinyl alcohol) on the textile fabrics in the finishing processes enables to enhance the stiffness as well as helps to improve its pilling resistance.

Research paper thumbnail of Preparation of rich handles soft cellulosic fabric using amino silicone based softener, part II: Colorfastness properties

International Journal of Biological Macromolecules, 2011

A series of amino silicone based softeners with different emulsifiers were prepared and adsorbed ... more A series of amino silicone based softeners with different emulsifiers were prepared and adsorbed onto the surfaces of cotton and blends of cotton/polyester fabrics. Factors affecting the performance properties of the finished substrate such as post-treatment with amino functional silicone based softener varying different emulsifiers in their formulations and its concentration on different processed fabrics were studied. Fixation of the amino-functional silicone softener onto/or within the cellulose structure is accompanied by the formation of semi-inter-penetrated network structure thereby enhancing both the extent of crosslinking and networking as well as providing very high softness. The results of the experiments indicate that the amino silicone can form a hydrophobic film on both cotton and blends of cotton/polyester fabrics and its coating reduces the surface roughness significantly. Furthermore, the roughness becomes lesser with an increase in the applied strength of amino silicone based softener.

Research paper thumbnail of Preparation of rich handles soft cellulosic fabric using amino silicone based softener. PartI: Surface smoothness and softness properties

International Journal of Biological Macromolecules, 2011

A series of amino silicone based softeners with different emulsifiers were prepared and adsorbed ... more A series of amino silicone based softeners with different emulsifiers were prepared and adsorbed onto the surfaces of cotton and blends of cotton/polyester fabrics. Factors affecting the performance properties of the finished substrate such as post-treatment with amino functional silicone based softener varying different emulsifiers in their formulations and its concentration on different processed fabrics were studied. Fixation of the amino-functional silicone softener onto/or within the cellulose structure is accompanied by the formation of semi-inter-penetrated network structure thereby enhancing both the extent of crosslinking and networking as well as providing very high softness. The results of the experiments indicate that the amino silicone can form a hydrophobic film on both cotton and blends of cotton/polyester fabrics and its coating reduces the surface roughness significantly. Furthermore, the roughness becomes lesser with an increase in the applied strength of amino silicone based softener.

Research paper thumbnail of Cytotoxicity and mechanical behavior of chitin–bentonite clay based polyurethane bio-nanocomposites

International Journal of Biological Macromolecules, 2011

Chitin based polyurethane bio-nanocomposites (PUBNC) were prepared using chitin, Delite ® HPS ben... more Chitin based polyurethane bio-nanocomposites (PUBNC) were prepared using chitin, Delite ® HPS bentonite nanoclay enriched in montmorillonite (MMT), 4,4 -diphenylmethane diisocyanate (MDI) and polycaprolactone polyol CAPA 231 (3000 g/mol −1 ). The prepolymers having different concentration of Delite HPS bentonite nanoclay were extended with 2 moles of chitin. The structures of the resulted polymers were determined by FT-IR technique. The effect of nanoclay contents on mechanical properties and in vitro biocompatibility was investigated. The mechanical properties of the synthesized materials were improved with increase in the Delite HPS ® bentonite nanoclay contents. Optimum mechanical properties were obtained from the PU bio-nanocomposite samples having 4% Delite HPS ® bentonite nanoclay. The results revealed that the final PU bio-nanocomposite having 2% Delite HPS ® bentonite nanoclay contents is ideal contenders for surgical threads with on going investigations into their in vitro biocompatibility, non-toxicity, and mechanical properties.

Research paper thumbnail of Modification of cellulosic fabric using polyvinyl alcohol, Part-II: Colorfastness properties

Carbohydrate Polymers

A series of poly(vinyl alcohol) of different commercial grades were prepared and applied onto the... more A series of poly(vinyl alcohol) of different commercial grades were prepared and applied onto the surfaces of cotton and blends of cotton/polyester fibers. The molecular structure was confirmed using Fourier Transform Infrared spectroscopy. Physicochemical properties such as viscosity and solid contents (%) were determined and discussed. Factors affecting the performance properties of the finished substrate such as post-treatment with poly(vinyl alcohol) of different grades, concentration and dilutions were studied. Fixation of the poly(vinyl alcohol) onto/or within the cellulose structure is accompanied by the formation of semi-inter-penetrated network structure thereby enhancing the association as well as providing very high stiffness. The results revealed that applications of poly(vinyl alcohol) on the textile fabrics in the finishing processes enables to enhance the stiffness as well as helps to improve its pilling resistance.

Research paper thumbnail of Effect of additives on the properties and performance of cellulose acetate derivative membranes in the separation of isopropanol/water mixtures

Desalination

In this work, various cellulose acetate (CA) membranes for pervaporation were prepared by the inc... more In this work, various cellulose acetate (CA) membranes for pervaporation were prepared by the incorporation of different additives, i.e. polyethylene glycol-600 (PEG-600), propylene glycol (PG), and ethylene glycol (EG) to enhance the separation of isopropanol (IPA)/water mixtures. These membranes were characterized by FTIR, DSC, TGA, SEM and UTM. Each additive was responsible for its characteristic effect on the membrane morphology, mechanical strength, permeation flux and separation factor. The SEM micrograph showed that the additives were evenly dispersed in the membrane matrix with the formation of dense membranes. The UTM tests for the membrane reveled that both the Young's Modulus and tensile strength increased with the increase in additive contents. TGA studies for the CA/PEG blend membrane exhibited the highest thermal stability as compared to the CA/PG and CA/EG blends. For each of these synthesized membranes, the separation factor decreased while the permeation flux increased with the increase in additive contents, while the CA/PG membrane with 20 wt.% additive content showed highest permeation flux of 452.27 g/m 2 h.

Research paper thumbnail of Influence of glycol additives on the structure and performance of cellulose acetate/zinc oxide blend membranes

Desalination, 2011

The effects of different types and concentration of glycol additives in the membrane blend formul... more The effects of different types and concentration of glycol additives in the membrane blend formulations for pervaporation studies were investigated. The glycol additives used were polyethylene glycol 600 (PEG 600), propylene glycol (PG) and ethylene glycol (EG). Glycol additive filled ...

Research paper thumbnail of Dependence of the Electrophoretic Mobility of DNA in Gels on Field Intermittency

Journal of Biomolecular Structure & Dynamics, 1985

The electrophoretic mobility of double helical DNA in agarose and Polyacrylamide gels increases a... more The electrophoretic mobility of double helical DNA in agarose and Polyacrylamide gels increases as a function of time after the electric field is applied to the gel and decreases after the field is terminated. The changes are large for long (more than 10 kb) molecules. The effects of other variables are indicated.

Research paper thumbnail of Relaxation effects in the gel electrophoresis of DNA in intermittent fields

Biopolymers, 1989

The electrophoretic mobility of restriction fragments of lambda DNA in agarose gels declines if t... more The electrophoretic mobility of restriction fragments of lambda DNA in agarose gels declines if the field is intermittent rather than continuous, with a greater effect on the longer fragments. The changes are compatible with the assumption of two exponential relaxation processes for field-dependent configurational changes, one when the field is turned on and another when it terminates. The length dependence at the extrapolated limit of mobility for short pulses with long intervals corresponds closely to the simple inverse proportionality to length expected from theoretical considerations when the molecular configuration is not affected by the electric field. Simple intermittent fields would allow separation of longer molecules than can ordinarily be resolved. The relaxation times for both the change in conformation imposed by the field and the return to field-free conformation vary as approximately the second power of the length of the molecule, independent of the salt concentration or field strength and varying only slightly with gel density. These relations are not in good agreement with properties expected from reptation theory, and they suggest that a different mechanism must be invoked for the electrophoretic migration of long DNA molecules at ordinary values of field strength.

Research paper thumbnail of Modification of cellulosic fabric using polyvinyl alcohol—PartI: Physicochemical properties

Carbohydrate Polymers

A series of poly(vinyl alcohol) of different commercial grades were prepared and applied onto the... more A series of poly(vinyl alcohol) of different commercial grades were prepared and applied onto the surfaces of cotton and blends of cotton/polyester fibers. The molecular structure was confirmed using Fourier Transform Infrared spectroscopy. Physicochemical properties such as viscosity and solid contents (%) were determined and discussed. Factors affecting the performance properties of the finished substrate such as post-treatment with poly(vinyl alcohol) of different grades, concentration and dilutions were studied. Fixation of the poly(vinyl alcohol) onto/or within the cellulose structure is accompanied by the formation of semi-inter-penetrated network structure thereby enhancing the association as well as providing very high stiffness. The results revealed that applications of poly(vinyl alcohol) on the textile fabrics in the finishing processes enables to enhance the stiffness as well as helps to improve its pilling resistance.

Research paper thumbnail of Preparation of rich handles soft cellulosic fabric using amino silicone based softener, part II: Colorfastness properties

International Journal of Biological Macromolecules, 2011

A series of amino silicone based softeners with different emulsifiers were prepared and adsorbed ... more A series of amino silicone based softeners with different emulsifiers were prepared and adsorbed onto the surfaces of cotton and blends of cotton/polyester fabrics. Factors affecting the performance properties of the finished substrate such as post-treatment with amino functional silicone based softener varying different emulsifiers in their formulations and its concentration on different processed fabrics were studied. Fixation of the amino-functional silicone softener onto/or within the cellulose structure is accompanied by the formation of semi-inter-penetrated network structure thereby enhancing both the extent of crosslinking and networking as well as providing very high softness. The results of the experiments indicate that the amino silicone can form a hydrophobic film on both cotton and blends of cotton/polyester fabrics and its coating reduces the surface roughness significantly. Furthermore, the roughness becomes lesser with an increase in the applied strength of amino silicone based softener.

Research paper thumbnail of Preparation of rich handles soft cellulosic fabric using amino silicone based softener. PartI: Surface smoothness and softness properties

International Journal of Biological Macromolecules, 2011

A series of amino silicone based softeners with different emulsifiers were prepared and adsorbed ... more A series of amino silicone based softeners with different emulsifiers were prepared and adsorbed onto the surfaces of cotton and blends of cotton/polyester fabrics. Factors affecting the performance properties of the finished substrate such as post-treatment with amino functional silicone based softener varying different emulsifiers in their formulations and its concentration on different processed fabrics were studied. Fixation of the amino-functional silicone softener onto/or within the cellulose structure is accompanied by the formation of semi-inter-penetrated network structure thereby enhancing both the extent of crosslinking and networking as well as providing very high softness. The results of the experiments indicate that the amino silicone can form a hydrophobic film on both cotton and blends of cotton/polyester fabrics and its coating reduces the surface roughness significantly. Furthermore, the roughness becomes lesser with an increase in the applied strength of amino silicone based softener.

Research paper thumbnail of Cytotoxicity and mechanical behavior of chitin–bentonite clay based polyurethane bio-nanocomposites

International Journal of Biological Macromolecules, 2011

Chitin based polyurethane bio-nanocomposites (PUBNC) were prepared using chitin, Delite ® HPS ben... more Chitin based polyurethane bio-nanocomposites (PUBNC) were prepared using chitin, Delite ® HPS bentonite nanoclay enriched in montmorillonite (MMT), 4,4 -diphenylmethane diisocyanate (MDI) and polycaprolactone polyol CAPA 231 (3000 g/mol −1 ). The prepolymers having different concentration of Delite HPS bentonite nanoclay were extended with 2 moles of chitin. The structures of the resulted polymers were determined by FT-IR technique. The effect of nanoclay contents on mechanical properties and in vitro biocompatibility was investigated. The mechanical properties of the synthesized materials were improved with increase in the Delite HPS ® bentonite nanoclay contents. Optimum mechanical properties were obtained from the PU bio-nanocomposite samples having 4% Delite HPS ® bentonite nanoclay. The results revealed that the final PU bio-nanocomposite having 2% Delite HPS ® bentonite nanoclay contents is ideal contenders for surgical threads with on going investigations into their in vitro biocompatibility, non-toxicity, and mechanical properties.

Research paper thumbnail of Modification of cellulosic fabric using polyvinyl alcohol, Part-II: Colorfastness properties

Carbohydrate Polymers

A series of poly(vinyl alcohol) of different commercial grades were prepared and applied onto the... more A series of poly(vinyl alcohol) of different commercial grades were prepared and applied onto the surfaces of cotton and blends of cotton/polyester fibers. The molecular structure was confirmed using Fourier Transform Infrared spectroscopy. Physicochemical properties such as viscosity and solid contents (%) were determined and discussed. Factors affecting the performance properties of the finished substrate such as post-treatment with poly(vinyl alcohol) of different grades, concentration and dilutions were studied. Fixation of the poly(vinyl alcohol) onto/or within the cellulose structure is accompanied by the formation of semi-inter-penetrated network structure thereby enhancing the association as well as providing very high stiffness. The results revealed that applications of poly(vinyl alcohol) on the textile fabrics in the finishing processes enables to enhance the stiffness as well as helps to improve its pilling resistance.

Research paper thumbnail of Effect of additives on the properties and performance of cellulose acetate derivative membranes in the separation of isopropanol/water mixtures

Desalination

In this work, various cellulose acetate (CA) membranes for pervaporation were prepared by the inc... more In this work, various cellulose acetate (CA) membranes for pervaporation were prepared by the incorporation of different additives, i.e. polyethylene glycol-600 (PEG-600), propylene glycol (PG), and ethylene glycol (EG) to enhance the separation of isopropanol (IPA)/water mixtures. These membranes were characterized by FTIR, DSC, TGA, SEM and UTM. Each additive was responsible for its characteristic effect on the membrane morphology, mechanical strength, permeation flux and separation factor. The SEM micrograph showed that the additives were evenly dispersed in the membrane matrix with the formation of dense membranes. The UTM tests for the membrane reveled that both the Young's Modulus and tensile strength increased with the increase in additive contents. TGA studies for the CA/PEG blend membrane exhibited the highest thermal stability as compared to the CA/PG and CA/EG blends. For each of these synthesized membranes, the separation factor decreased while the permeation flux increased with the increase in additive contents, while the CA/PG membrane with 20 wt.% additive content showed highest permeation flux of 452.27 g/m 2 h.

Research paper thumbnail of Influence of glycol additives on the structure and performance of cellulose acetate/zinc oxide blend membranes

Desalination, 2011

The effects of different types and concentration of glycol additives in the membrane blend formul... more The effects of different types and concentration of glycol additives in the membrane blend formulations for pervaporation studies were investigated. The glycol additives used were polyethylene glycol 600 (PEG 600), propylene glycol (PG) and ethylene glycol (EG). Glycol additive filled ...

Research paper thumbnail of Dependence of the Electrophoretic Mobility of DNA in Gels on Field Intermittency

Journal of Biomolecular Structure & Dynamics, 1985

The electrophoretic mobility of double helical DNA in agarose and Polyacrylamide gels increases a... more The electrophoretic mobility of double helical DNA in agarose and Polyacrylamide gels increases as a function of time after the electric field is applied to the gel and decreases after the field is terminated. The changes are large for long (more than 10 kb) molecules. The effects of other variables are indicated.

Research paper thumbnail of Relaxation effects in the gel electrophoresis of DNA in intermittent fields

Biopolymers, 1989

The electrophoretic mobility of restriction fragments of lambda DNA in agarose gels declines if t... more The electrophoretic mobility of restriction fragments of lambda DNA in agarose gels declines if the field is intermittent rather than continuous, with a greater effect on the longer fragments. The changes are compatible with the assumption of two exponential relaxation processes for field-dependent configurational changes, one when the field is turned on and another when it terminates. The length dependence at the extrapolated limit of mobility for short pulses with long intervals corresponds closely to the simple inverse proportionality to length expected from theoretical considerations when the molecular configuration is not affected by the electric field. Simple intermittent fields would allow separation of longer molecules than can ordinarily be resolved. The relaxation times for both the change in conformation imposed by the field and the return to field-free conformation vary as approximately the second power of the length of the molecule, independent of the salt concentration or field strength and varying only slightly with gel density. These relations are not in good agreement with properties expected from reptation theory, and they suggest that a different mechanism must be invoked for the electrophoretic migration of long DNA molecules at ordinary values of field strength.