Gurinder Kaur - Academia.edu (original) (raw)

Papers by Gurinder Kaur

Research paper thumbnail of Effect of antimony impurity on photoconduction in thin films of SeTe system

Solid State Communications, 1993

Effect of antimony impurity concentration on the steady state and transient photoconductivity of ... more Effect of antimony impurity concentration on the steady state and transient photoconductivity of amorphous Se-Te films has been investigated by exposing the material to white light. Photoconductivity is found to increase with the increase in Sb content and shows a square root dependence on intensity of light. The photosensitivity decreases with increasing Sb content. Nonexponential long-term photocurrent decays have been observed after ceasing the steady illumination. The results have been discussed on the basis of localized-localized recombination and the concept of differential lifetime.

Research paper thumbnail of Mixed micelles of benzyldimethyltetradecylammonium chloride with tetradecyltrimethylammonium and tetradecyltriphenylphosphonium bromides: a head group contribution

Mixed micelle formation by tetradecyltrimethylammonium (TTAB) and tetradecyltriphenylphosphonium ... more Mixed micelle formation by tetradecyltrimethylammonium (TTAB) and tetradecyltriphenylphosphonium bromides (TTPB) with benzyldimethyltetradecylammonium chloride (BTDACl) was studied with the help of conductivity and Kraft point measurements. The BTDACl + TTAB mixtures showed synergistic interactions whereas those of BTDACl + TTPB indicated weak antagonistic behavior. From Kraft temperature measurements, the enthalpy of fusion (H 0 1) from solid hydrated BTDACl to the liquid state in the presence of TTAB or TTPB was computed. It was found that H 0 1 was much more positive for BTDACl + TTPB than for BTDACl + TTAB mixtures.

Research paper thumbnail of Mixed-micelle formation by strongly interacting surfactant binary mixtures: effect of head-group modification

Colloid and Polymer Science, Oct 31, 2002

with the packing geometrical constraints are responsible for the close-to-ideal behavior of the S... more with the packing geometrical constraints are responsible for the close-to-ideal behavior of the SDBS plus TTPB mixture. Keywords Strongly interacting surfactants AE Mixed micelles AE Bulky head groups AE Turbidity

Research paper thumbnail of Thermodynamic Behavior of Mixtures. 3. Mixtures of Acetonitrile with Dimethylacetamide, Dimethyl Sulfoxide, Nitrobenzene, and Methanol at 25 °C

J Chem Eng Data, 1996

In our recent work (Bakshi, 1993a,b), we have been exploring the intermixing behavior of polar or... more In our recent work (Bakshi, 1993a,b), we have been exploring the intermixing behavior of polar organic solvents. Especially nitrogen organic bases were of interest because of their strong basic nature and unique mixing behavior. It has been found that in most of the cases, the results ...

Research paper thumbnail of Nanoparticle Surface Specific Adsorption of Zein and Its Self-assembled Behavior of Nanocubes Formation in Relation to On-Off SERS: Understanding Morphology Control of Protein Aggregates

Journal of agricultural and food chemistry, Jan 13, 2016

Zein, an industrially important protein, is characterized in terms of its food and pharmaceutical... more Zein, an industrially important protein, is characterized in terms of its food and pharmaceutical coating applications by using surface enhanced Raman spectroscopy (SERS) on Au, Ag, and PbS nanoparticles (NPs). Its specific surface adsorption behavior on Ag NPs produced self-assembled zein nanocubes which demonstrated on and off SERS activity. Both SERS characterization as well as nanocube formation of zein helped us to understand the complex protein aggregation behavior in shape controlled morphologies, a process with significant ramifications in protein crystallization to achieve ordered morphologies. Interestingly, nanocube formation was promoted in the presence of Ag rather than Au or PbS NPs under in situ synthesis and discussed in terms of specific adsorption. Zein fingerprinting was much more clear and enhanced on Au surface in comparison to Ag while PbS did not demonstrate SERS due to its semiconducting nature.

Research paper thumbnail of Fluorescence study of solubilization of -α-dilauroylphosphatidylethanolamine in the mixed micelles with monomeric and dimeric cationic surfactants

J Photochem Photobiol a Chem, 2005

Research paper thumbnail of Shape and size controlled lead sulfide quantum dots for optical refrigeration applications

Quantum Dots and Nanostructures: Synthesis, Characterization, and Modeling XII, 2015

Research paper thumbnail of Lysozyme Complexes for the Synthesis of Functionalized Biomaterials To Understand Protein–Protein Interactions and Their Biological Applications

The Journal of Physical Chemistry C, 2014

ABSTRACT

Research paper thumbnail of Protein mixtures of environmentally friendly zein to understand protein–protein interactions through biomaterials synthesis, hemolysis, and their antimicrobial activities

Physical Chemistry Chemical Physics, 2014

Protein–protein interactions through biomaterials synthesis for biological applications.

Research paper thumbnail of Antimony-doping effect on the ac conductivity of the amorphous Se-Te system

Physical Review B, 1991

ABSTRACT

Research paper thumbnail of Novel Biodegradable Films with Extraordinary Tensile Strength and Flexibility Provided by Nanoparticles

ACS Sustainable Chemistry & Engineering, 2012

Research paper thumbnail of Protein Films of Bovine Serum Albumen Conjugated Gold Nanoparticles: A Synthetic Route from Bioconjugated Nanoparticles to Biodegradable Protein Films

The Journal of Physical Chemistry C, 2011

Bovine serum albumen (BSA) conjugated gold (Au) nanoparticles (NPs) were directly synthesized by ... more Bovine serum albumen (BSA) conjugated gold (Au) nanoparticles (NPs) were directly synthesized by using BSA as a weak reducing agent against HAuCl4 in aqueous phase. A systematic variation in Au/BSA mole ratio showed a dramatic change in the size and ...

Research paper thumbnail of Tuning the Shape and Size of Gold Nanoparticles with Triblock Polymer Micelle Structure Transitions and Environments

The Journal of Physical Chemistry C, 2011

Water-soluble poly(ethylene oxide)-b-poly(propylene oxide)b-poly(ethylene oxide) (PEO-b-PPO-b-PEO... more Water-soluble poly(ethylene oxide)-b-poly(propylene oxide)b-poly(ethylene oxide) (PEO-b-PPO-b-PEO) triblock copolymers (TBPs) are polymeric surfactants. 1 They undergo micelle formation, which is affected by concentration as well as temperature. 1k The TBP micelle is made up of a PPO core and a PEO corona (Scheme 1) and demonstrates several interesting shape transitions which are closely associated with a number of factors such as the molar masses of the PEO or PPO units, salt additives, the nature of the solvent, concentration, and temperature. 2 Predominantly hydrophilic TBPs with a greater number of PEO units than PPO units are also prone to the formation of compound micelles, 2fÀh but predominantly hydrophobic TBPs usually produce well-defined micelles. Micelles undergo several structure transitions (i.e., micelles f threadlike micelles f vesicles, etc.) with concentration and temperature variations. 3 Temperature brings marked dehydration to a greater magnitude of PPO than

Research paper thumbnail of Shape-Controlled Synthesis of Poly(styrene sulfonate) and Poly(vinyl pyrolidone) Capped Lead Sulfide Nanocubes, Bars, and Threads

The Journal of Physical Chemistry C, 2008

Research paper thumbnail of Bovine Serum Albumin Bioconjugated Gold Nanoparticles: Synthesis, Hemolysis, and Cytotoxicity toward Cancer Cell Lines

The Journal of Physical Chemistry C, 2012

Research paper thumbnail of Nonideal Mixing of Se−Te in Aqueous Micellar Phase for Nanoalloys Over the Whole Mole Mixing Range with Morphology Control from Nanoparticles to Nanoribbons

The Journal of Physical Chemistry C, 2010

Research paper thumbnail of Block copolymer micelles as nanoreactors for single-site polymerization catalysts

Journal of Polymer Science Part A: Polymer Chemistry, 2009

New micelle-like organic supports for single site catalysts based on the self-assembly of polysty... more New micelle-like organic supports for single site catalysts based on the self-assembly of polystyrene-b-poly(4-vinylbenzoic acid) block copolymers have been designed. These block copolymers were synthesized by sequential atom transfer radical polymerization (ATRP) of styrene and methyl 4-vinylbenzoate, followed by hydrolysis. As evidenced by dynamic light scattering, self-assembly in toluene that is a selective solvent of polystyrene, induced the formation of micelle-like nanoparticles composed of a poly(4-vinylbenzoic acid) core and a polystyrene corona. Further addition of trimethylaluminium (TMA) afforded in situ MAO-like species by diffusion of TMA into the core of the micelles and its subsequent reaction with the benzoic acid groups. Such reactive micelles then served as nanoreactors, MAO-like species being efficient activators of 2,6-bis[1-{(2,6-diisopropylphenyl)imino}ethyl]pyridinyl iron toward ethylene polymerization. These new micelle-like organic supports enabled the production of polyethylene beads with a spherical morphology and a high bulk density through homogeneous-like catalysis. V

Research paper thumbnail of Effect of hydrophobic tail on the mixed micelles of diheptanoylphosphatidycholine with cationic and zwitterionic surfactants: a fluorescence study

Journal of Photochemistry and Photobiology A: Chemistry, 2005

The pyrere fluorescence measurements have been performed for the mixtures of diheptanoylphosphati... more The pyrere fluorescence measurements have been performed for the mixtures of diheptanoylphosphatidycholine (DHPC) with dimeric cationic, phosphonium cationic, and zwitterionic surfactants of C 10 to C 16 hydrocarbon tail length over the whole mixing range. From the I 1 /I 3 versus total surfactant concentration plots, the mixed critical micelle concentration (cmc) of various mixtures was computed. The nature of the mixed micelles between the unlike components was determined by applying the regular solution theory. It was observed that all the mixtures show attractive interactions between the binary components and the interactions becomes more intense with the increase in length of the hydrocarbon tail of cosurfactant. The increase in the length of cosurfactant allowed greater amount of DHPC to be accommodated in the mixed micelles, which in return brought stronger synergism. A variation in the Stern-Volmer constant, K SV , further supports these results.

Research paper thumbnail of Fluorescence study of solubilization of l-α-dilauroylphosphatidylethanolamine in the mixed micelles with monomeric and dimeric cationic surfactants

Journal of Photochemistry and Photobiology A: Chemistry, 2005

The mixed micelle formation between l-α-dilauroylphosphatidylethanolamine (DLPE) and a series of ... more The mixed micelle formation between l-α-dilauroylphosphatidylethanolamine (DLPE) and a series of monomeric and dimeric cationic surfactants have been studied with the help of steady state fluorescence technique. The micelle formation process has been detected by plotting the emission intensities of solubilized fluorescence probes such as 5(6)-carboxyfluorescein (CF) and pyrene (Py) in the hydrophobic environment of mixed micelles. The mixed micelle

Research paper thumbnail of Effect of Sodium dodecylsulfate and Dodecyltrimethyl Ammonium Bromide on the Morphologies of Gold Nanoparticles in the Presence of Poly(amidoamine) Dendrimers

Journal of Nanoscience and Nanotechnology, 2006

The synthesis of gold nanoparticles has been carried out in aqueous phase in the presence of both... more The synthesis of gold nanoparticles has been carried out in aqueous phase in the presence of both ionic surfactants (i.e., sodium dodecylsulfate (SDS) and dodecyltrimethylammonium bromide (DTAB)) and poly(amidoamine) dendrimers (PAMAM). It has been observed that the fluoroderivative of 2G PAMAM (2D) acts as reducing agent in reducing Au(III) to Au(0) leading to the formation of fine gold nanoparticles. This process has been further evaluated in the presence of fixed amounts of both SDS and DTAB in their respective pre and post micellar concentration regions. The presence of SDS leads to the appearance of clear ordered morphologies such as triangular, hexagonal, spherical, and rod shaped, while the presence of DTAB does not show this effect. The formation of nanoparticles in triangular morphologies is more significant in the premicellar concentration range of SDS whereas hexagonal morphologies in the post micellar concentration range. On the contrary, increase in the DTAB concentrati...

Research paper thumbnail of Effect of antimony impurity on photoconduction in thin films of SeTe system

Solid State Communications, 1993

Effect of antimony impurity concentration on the steady state and transient photoconductivity of ... more Effect of antimony impurity concentration on the steady state and transient photoconductivity of amorphous Se-Te films has been investigated by exposing the material to white light. Photoconductivity is found to increase with the increase in Sb content and shows a square root dependence on intensity of light. The photosensitivity decreases with increasing Sb content. Nonexponential long-term photocurrent decays have been observed after ceasing the steady illumination. The results have been discussed on the basis of localized-localized recombination and the concept of differential lifetime.

Research paper thumbnail of Mixed micelles of benzyldimethyltetradecylammonium chloride with tetradecyltrimethylammonium and tetradecyltriphenylphosphonium bromides: a head group contribution

Mixed micelle formation by tetradecyltrimethylammonium (TTAB) and tetradecyltriphenylphosphonium ... more Mixed micelle formation by tetradecyltrimethylammonium (TTAB) and tetradecyltriphenylphosphonium bromides (TTPB) with benzyldimethyltetradecylammonium chloride (BTDACl) was studied with the help of conductivity and Kraft point measurements. The BTDACl + TTAB mixtures showed synergistic interactions whereas those of BTDACl + TTPB indicated weak antagonistic behavior. From Kraft temperature measurements, the enthalpy of fusion (H 0 1) from solid hydrated BTDACl to the liquid state in the presence of TTAB or TTPB was computed. It was found that H 0 1 was much more positive for BTDACl + TTPB than for BTDACl + TTAB mixtures.

Research paper thumbnail of Mixed-micelle formation by strongly interacting surfactant binary mixtures: effect of head-group modification

Colloid and Polymer Science, Oct 31, 2002

with the packing geometrical constraints are responsible for the close-to-ideal behavior of the S... more with the packing geometrical constraints are responsible for the close-to-ideal behavior of the SDBS plus TTPB mixture. Keywords Strongly interacting surfactants AE Mixed micelles AE Bulky head groups AE Turbidity

Research paper thumbnail of Thermodynamic Behavior of Mixtures. 3. Mixtures of Acetonitrile with Dimethylacetamide, Dimethyl Sulfoxide, Nitrobenzene, and Methanol at 25 °C

J Chem Eng Data, 1996

In our recent work (Bakshi, 1993a,b), we have been exploring the intermixing behavior of polar or... more In our recent work (Bakshi, 1993a,b), we have been exploring the intermixing behavior of polar organic solvents. Especially nitrogen organic bases were of interest because of their strong basic nature and unique mixing behavior. It has been found that in most of the cases, the results ...

Research paper thumbnail of Nanoparticle Surface Specific Adsorption of Zein and Its Self-assembled Behavior of Nanocubes Formation in Relation to On-Off SERS: Understanding Morphology Control of Protein Aggregates

Journal of agricultural and food chemistry, Jan 13, 2016

Zein, an industrially important protein, is characterized in terms of its food and pharmaceutical... more Zein, an industrially important protein, is characterized in terms of its food and pharmaceutical coating applications by using surface enhanced Raman spectroscopy (SERS) on Au, Ag, and PbS nanoparticles (NPs). Its specific surface adsorption behavior on Ag NPs produced self-assembled zein nanocubes which demonstrated on and off SERS activity. Both SERS characterization as well as nanocube formation of zein helped us to understand the complex protein aggregation behavior in shape controlled morphologies, a process with significant ramifications in protein crystallization to achieve ordered morphologies. Interestingly, nanocube formation was promoted in the presence of Ag rather than Au or PbS NPs under in situ synthesis and discussed in terms of specific adsorption. Zein fingerprinting was much more clear and enhanced on Au surface in comparison to Ag while PbS did not demonstrate SERS due to its semiconducting nature.

Research paper thumbnail of Fluorescence study of solubilization of -α-dilauroylphosphatidylethanolamine in the mixed micelles with monomeric and dimeric cationic surfactants

J Photochem Photobiol a Chem, 2005

Research paper thumbnail of Shape and size controlled lead sulfide quantum dots for optical refrigeration applications

Quantum Dots and Nanostructures: Synthesis, Characterization, and Modeling XII, 2015

Research paper thumbnail of Lysozyme Complexes for the Synthesis of Functionalized Biomaterials To Understand Protein–Protein Interactions and Their Biological Applications

The Journal of Physical Chemistry C, 2014

ABSTRACT

Research paper thumbnail of Protein mixtures of environmentally friendly zein to understand protein–protein interactions through biomaterials synthesis, hemolysis, and their antimicrobial activities

Physical Chemistry Chemical Physics, 2014

Protein–protein interactions through biomaterials synthesis for biological applications.

Research paper thumbnail of Antimony-doping effect on the ac conductivity of the amorphous Se-Te system

Physical Review B, 1991

ABSTRACT

Research paper thumbnail of Novel Biodegradable Films with Extraordinary Tensile Strength and Flexibility Provided by Nanoparticles

ACS Sustainable Chemistry & Engineering, 2012

Research paper thumbnail of Protein Films of Bovine Serum Albumen Conjugated Gold Nanoparticles: A Synthetic Route from Bioconjugated Nanoparticles to Biodegradable Protein Films

The Journal of Physical Chemistry C, 2011

Bovine serum albumen (BSA) conjugated gold (Au) nanoparticles (NPs) were directly synthesized by ... more Bovine serum albumen (BSA) conjugated gold (Au) nanoparticles (NPs) were directly synthesized by using BSA as a weak reducing agent against HAuCl4 in aqueous phase. A systematic variation in Au/BSA mole ratio showed a dramatic change in the size and ...

Research paper thumbnail of Tuning the Shape and Size of Gold Nanoparticles with Triblock Polymer Micelle Structure Transitions and Environments

The Journal of Physical Chemistry C, 2011

Water-soluble poly(ethylene oxide)-b-poly(propylene oxide)b-poly(ethylene oxide) (PEO-b-PPO-b-PEO... more Water-soluble poly(ethylene oxide)-b-poly(propylene oxide)b-poly(ethylene oxide) (PEO-b-PPO-b-PEO) triblock copolymers (TBPs) are polymeric surfactants. 1 They undergo micelle formation, which is affected by concentration as well as temperature. 1k The TBP micelle is made up of a PPO core and a PEO corona (Scheme 1) and demonstrates several interesting shape transitions which are closely associated with a number of factors such as the molar masses of the PEO or PPO units, salt additives, the nature of the solvent, concentration, and temperature. 2 Predominantly hydrophilic TBPs with a greater number of PEO units than PPO units are also prone to the formation of compound micelles, 2fÀh but predominantly hydrophobic TBPs usually produce well-defined micelles. Micelles undergo several structure transitions (i.e., micelles f threadlike micelles f vesicles, etc.) with concentration and temperature variations. 3 Temperature brings marked dehydration to a greater magnitude of PPO than

Research paper thumbnail of Shape-Controlled Synthesis of Poly(styrene sulfonate) and Poly(vinyl pyrolidone) Capped Lead Sulfide Nanocubes, Bars, and Threads

The Journal of Physical Chemistry C, 2008

Research paper thumbnail of Bovine Serum Albumin Bioconjugated Gold Nanoparticles: Synthesis, Hemolysis, and Cytotoxicity toward Cancer Cell Lines

The Journal of Physical Chemistry C, 2012

Research paper thumbnail of Nonideal Mixing of Se−Te in Aqueous Micellar Phase for Nanoalloys Over the Whole Mole Mixing Range with Morphology Control from Nanoparticles to Nanoribbons

The Journal of Physical Chemistry C, 2010

Research paper thumbnail of Block copolymer micelles as nanoreactors for single-site polymerization catalysts

Journal of Polymer Science Part A: Polymer Chemistry, 2009

New micelle-like organic supports for single site catalysts based on the self-assembly of polysty... more New micelle-like organic supports for single site catalysts based on the self-assembly of polystyrene-b-poly(4-vinylbenzoic acid) block copolymers have been designed. These block copolymers were synthesized by sequential atom transfer radical polymerization (ATRP) of styrene and methyl 4-vinylbenzoate, followed by hydrolysis. As evidenced by dynamic light scattering, self-assembly in toluene that is a selective solvent of polystyrene, induced the formation of micelle-like nanoparticles composed of a poly(4-vinylbenzoic acid) core and a polystyrene corona. Further addition of trimethylaluminium (TMA) afforded in situ MAO-like species by diffusion of TMA into the core of the micelles and its subsequent reaction with the benzoic acid groups. Such reactive micelles then served as nanoreactors, MAO-like species being efficient activators of 2,6-bis[1-{(2,6-diisopropylphenyl)imino}ethyl]pyridinyl iron toward ethylene polymerization. These new micelle-like organic supports enabled the production of polyethylene beads with a spherical morphology and a high bulk density through homogeneous-like catalysis. V

Research paper thumbnail of Effect of hydrophobic tail on the mixed micelles of diheptanoylphosphatidycholine with cationic and zwitterionic surfactants: a fluorescence study

Journal of Photochemistry and Photobiology A: Chemistry, 2005

The pyrere fluorescence measurements have been performed for the mixtures of diheptanoylphosphati... more The pyrere fluorescence measurements have been performed for the mixtures of diheptanoylphosphatidycholine (DHPC) with dimeric cationic, phosphonium cationic, and zwitterionic surfactants of C 10 to C 16 hydrocarbon tail length over the whole mixing range. From the I 1 /I 3 versus total surfactant concentration plots, the mixed critical micelle concentration (cmc) of various mixtures was computed. The nature of the mixed micelles between the unlike components was determined by applying the regular solution theory. It was observed that all the mixtures show attractive interactions between the binary components and the interactions becomes more intense with the increase in length of the hydrocarbon tail of cosurfactant. The increase in the length of cosurfactant allowed greater amount of DHPC to be accommodated in the mixed micelles, which in return brought stronger synergism. A variation in the Stern-Volmer constant, K SV , further supports these results.

Research paper thumbnail of Fluorescence study of solubilization of l-α-dilauroylphosphatidylethanolamine in the mixed micelles with monomeric and dimeric cationic surfactants

Journal of Photochemistry and Photobiology A: Chemistry, 2005

The mixed micelle formation between l-α-dilauroylphosphatidylethanolamine (DLPE) and a series of ... more The mixed micelle formation between l-α-dilauroylphosphatidylethanolamine (DLPE) and a series of monomeric and dimeric cationic surfactants have been studied with the help of steady state fluorescence technique. The micelle formation process has been detected by plotting the emission intensities of solubilized fluorescence probes such as 5(6)-carboxyfluorescein (CF) and pyrene (Py) in the hydrophobic environment of mixed micelles. The mixed micelle

Research paper thumbnail of Effect of Sodium dodecylsulfate and Dodecyltrimethyl Ammonium Bromide on the Morphologies of Gold Nanoparticles in the Presence of Poly(amidoamine) Dendrimers

Journal of Nanoscience and Nanotechnology, 2006

The synthesis of gold nanoparticles has been carried out in aqueous phase in the presence of both... more The synthesis of gold nanoparticles has been carried out in aqueous phase in the presence of both ionic surfactants (i.e., sodium dodecylsulfate (SDS) and dodecyltrimethylammonium bromide (DTAB)) and poly(amidoamine) dendrimers (PAMAM). It has been observed that the fluoroderivative of 2G PAMAM (2D) acts as reducing agent in reducing Au(III) to Au(0) leading to the formation of fine gold nanoparticles. This process has been further evaluated in the presence of fixed amounts of both SDS and DTAB in their respective pre and post micellar concentration regions. The presence of SDS leads to the appearance of clear ordered morphologies such as triangular, hexagonal, spherical, and rod shaped, while the presence of DTAB does not show this effect. The formation of nanoparticles in triangular morphologies is more significant in the premicellar concentration range of SDS whereas hexagonal morphologies in the post micellar concentration range. On the contrary, increase in the DTAB concentrati...