SUSHIL K VERMA - Academia.edu (original) (raw)
Papers by SUSHIL K VERMA
Polymers for Advanced Technologies, 2016
Core–shell carboxyl-functionalized multiwall carbon nanotube (c-MWCNT)/poly(m-aminophenol) (PmAP)... more Core–shell carboxyl-functionalized multiwall carbon nanotube (c-MWCNT)/poly(m-aminophenol) (PmAP) nanocomposite were prepared through in-situ polymerization of m-aminophenol (m-AP) in the presence of MWCNTs, and explicated as a dielectric material for electronic applications. The formation of thin PmAP layer on individual c-MWCNT with excellent molecular level interactions at interfaces was confirmed by morphological and spectroscopic analyses. Here we conducted a comparative study of the dielectric performances of PmAP based nanocomposite films with pristine MWCNTs and c-MWCNTs as fillers. Compared to PmAP/MWCNT nanocomposites, the PmAP/c-MWCNT nanocomposites exhibited higher dielectric permittivity and lower dielectric loss. The well dispersed c-MWCNTs in PmAP/c-MWCNT nanocomposite produce huge interfacial area together with numerous active polarized centers (crystallographic defects), which in turn intensified the Maxwell-Wagner-Sillars (MWS) effect based on excellent molecular level interactions and thus, produce large dielectric permittivity (8810 at 1 kHz). The percolation threshold of PmAP/c-MWCNT nanocomposites is found lower than that of the PmAP/MWCNT nanocomposites, which could be attributed to homogeneous distribution of c-MWCNTs and strong c-MWCNT//PmAP interfacial interactions in the nanocomposites. Copyright © 2016 John Wiley & Sons, Ltd.
physica status solidi (a), 2015
Sensors and Actuators B: Chemical, 2015
Carboxyl-functionalized multi-walled carbon nanotube (c-MWCNT) reinforced poly(m-aminophenol (PmA... more Carboxyl-functionalized multi-walled carbon nanotube (c-MWCNT) reinforced poly(m-aminophenol (PmAP) nanocomposite film was fabricated by in-situ chemical oxidation polymerization of m-aminophenol in presence of c-MWCNTs, and exploited it as an effective sensor material for detection of aliphatic alcohols. The presence site-selective interaction between the conjugated PmAP chain and the-bonded surface of c-MWCNT was confirmed by Fourier transform infrared (FT-IR) and Raman spectroscopy. The morphological analysis of the nanocomposite showed the formation of PmAP coating (thickness ∼100 nm) on the CNT surfaces. The X-ray and electron diffraction patterns of the nanocom-posites indicated the crystalline nature of the PmAP matrix. The nanocomposite with small quantity of c-MWCNT (2 wt%) was found to have sensing response about 114% and 96% higher than that of pure PmAP for methanol and ethanol vapor (90 ppm). This dramatic improvement of sensing performance might be attributed to the favorable interactions of c-MWCNTs with conjugated PmAP chains that subsequently generate a pathway for possible H-bonding/dipole interaction with the alcohol molecules. The nanocom-posite sensor also exhibits distinct features of the response curves and responsivity values for different aliphatic alcohols, which could be used as a basis for the selective detection of these pollutant vapors. The UV–vis and FT-IR analyses were used to explain the sensing mechanism.
Poly(m-aminophenol)/amine groups functionalized multi-walled carbon nanotube composite was prepar... more Poly(m-aminophenol)/amine groups functionalized multi-walled carbon nanotube composite was prepared by in-situ chemical polymerization and the film of the nanocomposite have been demonstrated as chemo-resistive sensor for ethanol. The functionalization of nanotube and the interfacial interaction between the poly(m-aminophenol) and functionalized nanotube within their composite was confirmed by Fourier transform infrared spectroscopy, X-beam photoelectron spectroscopy and Raman spectroscopy. Formation of polymer layers on the surfaces of nanotube was demonstrated form the morphological analysis of the nanocomposite by scanning electron microscopy and transmission electron microscopy. The percentage of functionalized nanotube was optimized as 2 wt% within the polymer matrix in terms of highest average DC-conductivity achieved as 32×10 −2 S cm −1 for that composition. The responses of nanocomposite with optimized composition toward various aliphatic alcohols vapor under dynamic flow with air were examined. The good response times and reasonable recovery times with significantly selective response for ethanol vapor was recorded.
The in-situ synthesis and characteristics of sulfonic acid group functionalized multi-walled carb... more The in-situ synthesis and characteristics of sulfonic acid group functionalized multi-walled carbon nanotubes incorporated poly(m-aminophenol) composite (PmAP/s-MWCNT) has been investigated. The fabricated nanocomposite film was successfully exploited as aliphatic alcohol vapor sensor material. The amount of s-MWCNT inside the PmAP matrix was optimized as about 2 wt% in terms of highest average conductivity achieved (3.2 3 10 À2 S/cm) for the composites due to induced site-selective interaction between the conjugated PmAP chain and s-MWCNT. The functionalization of MWCNT and the interfacial interaction in the nanocomposite was confirmed by spectro-scopic analysis. The morphological analysis of the nanocompo-site by Field emission scanning electron microscopy and transmission electron microscopy indicated the formation of PmAP layers (thickness ~ 200 nm) on the surfaces of s-MWCNTs. The nanocomposite sensor exhibited distinct features of the response curves and percent response values for different aliphatic alcohols especially for methanol and ethanol, which could be used as a basis for the selective detection of these pollutant vapors.
Core–shell carboxyl-functionalized multiwall carbon nanotube (c-MWCNT)/poly(m-aminophenol) (PmAP)... more Core–shell carboxyl-functionalized multiwall carbon nanotube (c-MWCNT)/poly(m-aminophenol) (PmAP) nanocom-posite were prepared through in-situ polymerization of m-aminophenol (mAP) in the presence of MWCNTs, and ex-plicated as a dielectric material for electronic applications. The formation of thin PmAP layer on individual c-MWCNT with excellent molecular level interactions at interfaces was confirmed by morphological and spectroscopic analyses. Here we conducted a comparative study of the dielectric performances of PmAP based nanocomposite films with pristine MWCNTs and c-MWCNTs as fillers. Compared to PmAP/MWCNT nanocomposites, the PmAP/c-MWCNT nanocomposites exhibited higher dielectric permittivity and lower dielectric loss. The well dispersed c-MWCNTs in PmAP/c-MWCNT nanocomposite produce huge interfacial area together with numerous active polarized centers (crystallographic defects), which in turn intensified the Maxwell-Wagner-Sillars (MWS) effect based on excellent molecular level interactions and thus, produce large dielectric permittivity (8810 at 1 kHz). The percolation threshold of PmAP/c-MWCNT nanocomposites is found lower than that of the PmAP/MWCNT nanocomposites, which could be attributed to homogeneous distribution of c-MWCNTs and strong c-MWCNT//PmAP interfacial interactions in the nanocomposites.
Poly(m-aminophenol)-multi-walled carbon nanotube (PmAP-MWCNT) composites are successfully synthes... more Poly(m-aminophenol)-multi-walled carbon nanotube (PmAP-MWCNT) composites are successfully synthesized by in situ chemical oxidative polymerization of m-aminophenol (mAP) with varying amount of MWCNT dispersion in aqueous sodium hydroxide medium. All the synthesized PmAP-MWCNT nanocomposites are found to be soluble in organic solvent and well free standing film is cast from the solution. Different techniques like Fourier transform infrared spectro-scopy, ultraviolet visible spectroscopy, X-ray diffraction, scanning electron microscopy, and transmission electron microscopy are used to study the interaction between PmAP and MWCNT within their nanocomposite. Thermal stability of the synthesized nanocomposites is analyzed by thermogravi-metric analysis. Without any other type of further doping, the highest average DC-conductivity of 1.3 Â 10 À7 S cm À1 is recorded for the PmAP-MWCNT nanocomposite having 3 wt% MWCNT. The optimum induced doping interaction of MWCNT with PmAP in terms of conductivity is explained on the basis of the above characterizations. The further increase in conductivity for the nanocomposites is observed by optimum sulfuric acid doping and highest conductivity is achieved as 1.03 Â 10 À3 S cm À1 for PmAP-MWCNT having 3 wt% MWCNT.
Carboxyl-functionalized multi-walled carbon nanotube (c-MWCNT) reinforced poly(m-aminophenol (PmA... more Carboxyl-functionalized multi-walled carbon nanotube (c-MWCNT) reinforced poly(m-aminophenol (PmAP) nanocomposite film was fabricated by in-situ chemical oxidation polymerization of m-aminophenol in presence of c-MWCNTs, and exploited it as an effective sensor material for detection of aliphatic alcohols. The presence site-selective interaction between the conjugated PmAP chain and the-bonded surface of c-MWCNT was confirmed by Fourier transform infrared (FT-IR) and Raman spectroscopy. The morphological analysis of the nanocomposite showed the formation of PmAP coating (thickness ∼100 nm) on the CNT surfaces. The X-ray and electron diffraction patterns of the nanocom-posites indicated the crystalline nature of the PmAP matrix. The nanocomposite with small quantity of c-MWCNT (2 wt%) was found to have sensing response about 114% and 96% higher than that of pure PmAP for methanol and ethanol vapor (90 ppm). This dramatic improvement of sensing performance might be attributed to the favorable interactions of c-MWCNTs with conjugated PmAP chains that subsequently generate a pathway for possible H-bonding/dipole interaction with the alcohol molecules. The nanocom-posite sensor also exhibits distinct features of the response curves and responsivity values for different aliphatic alcohols, which could be used as a basis for the selective detection of these pollutant vapors. The UV–vis and FT-IR analyses were used to explain the sensing mechanism.
Poly(m-aminophenol)-multi-walled carbon nanotube (PmAP-MWCNT) composites are successfully synthes... more Poly(m-aminophenol)-multi-walled carbon nanotube (PmAP-MWCNT) composites are successfully synthesized by in situ chemical oxidative polymerization of m-aminophenol (mAP) with varying amount of MWCNT dispersion in aqueous sodium hydroxide medium. All the synthesized PmAP-MWCNT nanocomposites are found to be soluble in organic solvent and well free standing film is cast from the solution. Different techniques like Fourier transform infrared spectro-scopy, ultraviolet visible spectroscopy, X-ray diffraction, scanning electron microscopy, and transmission electron microscopy are used to study the interaction between PmAP and MWCNT within their nanocomposite. Thermal stability of the synthesized nanocomposites is analyzed by thermogravi-metric analysis. Without any other type of further doping, the highest average DC-conductivity of 1.3 Â 10 À7 S cm À1 is recorded for the PmAP-MWCNT nanocomposite having 3 wt% MWCNT. The optimum induced doping interaction of MWCNT with PmAP in terms of conductivity is explained on the basis of the above characterizations. The further increase in conductivity for the nanocomposites is observed by optimum sulfuric acid doping and highest conductivity is achieved as 1.03 Â 10 À3 S cm À1 for PmAP-MWCNT having 3 wt% MWCNT.
Carboxyl-functionalized multi-walled carbon nanotube (c-MWCNT) reinforced poly(m-aminophenol (PmA... more Carboxyl-functionalized multi-walled carbon nanotube (c-MWCNT) reinforced poly(m-aminophenol (PmAP) nanocomposite film was fabricated by in-situ chemical oxidation polymerization of m-aminophenol in presence of c-MWCNTs, and exploited it as an effective sensor material for detection of aliphatic alcohols. The presence site-selective interaction between the conjugated PmAP chain and the-bonded surface of c-MWCNT was confirmed by Fourier transform infrared (FT-IR) and Raman spectroscopy. The morphological analysis of the nanocomposite showed the formation of PmAP coating (thickness ∼100 nm) on the CNT surfaces. The X-ray and electron diffraction patterns of the nanocom-posites indicated the crystalline nature of the PmAP matrix. The nanocomposite with small quantity of c-MWCNT (2 wt%) was found to have sensing response about 114% and 96% higher than that of pure PmAP for methanol and ethanol vapor (90 ppm). This dramatic improvement of sensing performance might be attributed to the favorable interactions of c-MWCNTs with conjugated PmAP chains that subsequently generate a pathway for possible H-bonding/dipole interaction with the alcohol molecules. The nanocom-posite sensor also exhibits distinct features of the response curves and responsivity values for different aliphatic alcohols, which could be used as a basis for the selective detection of these pollutant vapors. The UV–vis and FT-IR analyses were used to explain the sensing mechanism.
Core–shell carboxyl-functionalized multiwall carbon nanotube (c-MWCNT)/poly(m-aminophenol) (PmAP)... more Core–shell carboxyl-functionalized multiwall carbon nanotube (c-MWCNT)/poly(m-aminophenol) (PmAP) nanocom-posite were prepared through in-situ polymerization of m-aminophenol (mAP) in the presence of MWCNTs, and ex-plicated as a dielectric material for electronic applications. The formation of thin PmAP layer on individual c-MWCNT with excellent molecular level interactions at interfaces was confirmed by morphological and spectroscopic analyses. Here we conducted a comparative study of the dielectric performances of PmAP based nanocomposite films with pristine MWCNTs and c-MWCNTs as fillers. Compared to PmAP/MWCNT nanocomposites, the PmAP/c-MWCNT nanocomposites exhibited higher dielectric permittivity and lower dielectric loss. The well dispersed c-MWCNTs in PmAP/c-MWCNT nanocomposite produce huge interfacial area together with numerous active polarized centers (crystallographic defects), which in turn intensified the Maxwell-Wagner-Sillars (MWS) effect based on excellent molecular level interactions and thus, produce large dielectric permittivity (8810 at 1 kHz). The percolation threshold of PmAP/c-MWCNT nanocomposites is found lower than that of the PmAP/MWCNT nanocomposites, which could be attributed to homogeneous distribution of c-MWCNTs and strong c-MWCNT//PmAP interfacial interactions in the nanocomposites.
Journal of Applied Polymer Science, Nov 5, 2004
Skip to Main Content. ...
Mathematical Programming Series a and B, 2006
... Program., Ser. A 106, 391401 (2006) Ilan Adler · Richard W. Cottle · Sushil Verma Sufficient... more ... Program., Ser. A 106, 391401 (2006) Ilan Adler · Richard W. Cottle · Sushil Verma Sufficient matrices belong to L ... e-mail: sushil.verma@signaldemand.com Mathematics Subject Classification (2000): 90C33, 65K10, 15A99 Page 2. 392 I. Adler et al. ...
Polymers for Advanced Technologies, 2016
Core–shell carboxyl-functionalized multiwall carbon nanotube (c-MWCNT)/poly(m-aminophenol) (PmAP)... more Core–shell carboxyl-functionalized multiwall carbon nanotube (c-MWCNT)/poly(m-aminophenol) (PmAP) nanocomposite were prepared through in-situ polymerization of m-aminophenol (m-AP) in the presence of MWCNTs, and explicated as a dielectric material for electronic applications. The formation of thin PmAP layer on individual c-MWCNT with excellent molecular level interactions at interfaces was confirmed by morphological and spectroscopic analyses. Here we conducted a comparative study of the dielectric performances of PmAP based nanocomposite films with pristine MWCNTs and c-MWCNTs as fillers. Compared to PmAP/MWCNT nanocomposites, the PmAP/c-MWCNT nanocomposites exhibited higher dielectric permittivity and lower dielectric loss. The well dispersed c-MWCNTs in PmAP/c-MWCNT nanocomposite produce huge interfacial area together with numerous active polarized centers (crystallographic defects), which in turn intensified the Maxwell-Wagner-Sillars (MWS) effect based on excellent molecular level interactions and thus, produce large dielectric permittivity (8810 at 1 kHz). The percolation threshold of PmAP/c-MWCNT nanocomposites is found lower than that of the PmAP/MWCNT nanocomposites, which could be attributed to homogeneous distribution of c-MWCNTs and strong c-MWCNT//PmAP interfacial interactions in the nanocomposites. Copyright © 2016 John Wiley & Sons, Ltd.
physica status solidi (a), 2015
Sensors and Actuators B: Chemical, 2015
Carboxyl-functionalized multi-walled carbon nanotube (c-MWCNT) reinforced poly(m-aminophenol (PmA... more Carboxyl-functionalized multi-walled carbon nanotube (c-MWCNT) reinforced poly(m-aminophenol (PmAP) nanocomposite film was fabricated by in-situ chemical oxidation polymerization of m-aminophenol in presence of c-MWCNTs, and exploited it as an effective sensor material for detection of aliphatic alcohols. The presence site-selective interaction between the conjugated PmAP chain and the-bonded surface of c-MWCNT was confirmed by Fourier transform infrared (FT-IR) and Raman spectroscopy. The morphological analysis of the nanocomposite showed the formation of PmAP coating (thickness ∼100 nm) on the CNT surfaces. The X-ray and electron diffraction patterns of the nanocom-posites indicated the crystalline nature of the PmAP matrix. The nanocomposite with small quantity of c-MWCNT (2 wt%) was found to have sensing response about 114% and 96% higher than that of pure PmAP for methanol and ethanol vapor (90 ppm). This dramatic improvement of sensing performance might be attributed to the favorable interactions of c-MWCNTs with conjugated PmAP chains that subsequently generate a pathway for possible H-bonding/dipole interaction with the alcohol molecules. The nanocom-posite sensor also exhibits distinct features of the response curves and responsivity values for different aliphatic alcohols, which could be used as a basis for the selective detection of these pollutant vapors. The UV–vis and FT-IR analyses were used to explain the sensing mechanism.
Poly(m-aminophenol)/amine groups functionalized multi-walled carbon nanotube composite was prepar... more Poly(m-aminophenol)/amine groups functionalized multi-walled carbon nanotube composite was prepared by in-situ chemical polymerization and the film of the nanocomposite have been demonstrated as chemo-resistive sensor for ethanol. The functionalization of nanotube and the interfacial interaction between the poly(m-aminophenol) and functionalized nanotube within their composite was confirmed by Fourier transform infrared spectroscopy, X-beam photoelectron spectroscopy and Raman spectroscopy. Formation of polymer layers on the surfaces of nanotube was demonstrated form the morphological analysis of the nanocomposite by scanning electron microscopy and transmission electron microscopy. The percentage of functionalized nanotube was optimized as 2 wt% within the polymer matrix in terms of highest average DC-conductivity achieved as 32×10 −2 S cm −1 for that composition. The responses of nanocomposite with optimized composition toward various aliphatic alcohols vapor under dynamic flow with air were examined. The good response times and reasonable recovery times with significantly selective response for ethanol vapor was recorded.
The in-situ synthesis and characteristics of sulfonic acid group functionalized multi-walled carb... more The in-situ synthesis and characteristics of sulfonic acid group functionalized multi-walled carbon nanotubes incorporated poly(m-aminophenol) composite (PmAP/s-MWCNT) has been investigated. The fabricated nanocomposite film was successfully exploited as aliphatic alcohol vapor sensor material. The amount of s-MWCNT inside the PmAP matrix was optimized as about 2 wt% in terms of highest average conductivity achieved (3.2 3 10 À2 S/cm) for the composites due to induced site-selective interaction between the conjugated PmAP chain and s-MWCNT. The functionalization of MWCNT and the interfacial interaction in the nanocomposite was confirmed by spectro-scopic analysis. The morphological analysis of the nanocompo-site by Field emission scanning electron microscopy and transmission electron microscopy indicated the formation of PmAP layers (thickness ~ 200 nm) on the surfaces of s-MWCNTs. The nanocomposite sensor exhibited distinct features of the response curves and percent response values for different aliphatic alcohols especially for methanol and ethanol, which could be used as a basis for the selective detection of these pollutant vapors.
Core–shell carboxyl-functionalized multiwall carbon nanotube (c-MWCNT)/poly(m-aminophenol) (PmAP)... more Core–shell carboxyl-functionalized multiwall carbon nanotube (c-MWCNT)/poly(m-aminophenol) (PmAP) nanocom-posite were prepared through in-situ polymerization of m-aminophenol (mAP) in the presence of MWCNTs, and ex-plicated as a dielectric material for electronic applications. The formation of thin PmAP layer on individual c-MWCNT with excellent molecular level interactions at interfaces was confirmed by morphological and spectroscopic analyses. Here we conducted a comparative study of the dielectric performances of PmAP based nanocomposite films with pristine MWCNTs and c-MWCNTs as fillers. Compared to PmAP/MWCNT nanocomposites, the PmAP/c-MWCNT nanocomposites exhibited higher dielectric permittivity and lower dielectric loss. The well dispersed c-MWCNTs in PmAP/c-MWCNT nanocomposite produce huge interfacial area together with numerous active polarized centers (crystallographic defects), which in turn intensified the Maxwell-Wagner-Sillars (MWS) effect based on excellent molecular level interactions and thus, produce large dielectric permittivity (8810 at 1 kHz). The percolation threshold of PmAP/c-MWCNT nanocomposites is found lower than that of the PmAP/MWCNT nanocomposites, which could be attributed to homogeneous distribution of c-MWCNTs and strong c-MWCNT//PmAP interfacial interactions in the nanocomposites.
Poly(m-aminophenol)-multi-walled carbon nanotube (PmAP-MWCNT) composites are successfully synthes... more Poly(m-aminophenol)-multi-walled carbon nanotube (PmAP-MWCNT) composites are successfully synthesized by in situ chemical oxidative polymerization of m-aminophenol (mAP) with varying amount of MWCNT dispersion in aqueous sodium hydroxide medium. All the synthesized PmAP-MWCNT nanocomposites are found to be soluble in organic solvent and well free standing film is cast from the solution. Different techniques like Fourier transform infrared spectro-scopy, ultraviolet visible spectroscopy, X-ray diffraction, scanning electron microscopy, and transmission electron microscopy are used to study the interaction between PmAP and MWCNT within their nanocomposite. Thermal stability of the synthesized nanocomposites is analyzed by thermogravi-metric analysis. Without any other type of further doping, the highest average DC-conductivity of 1.3 Â 10 À7 S cm À1 is recorded for the PmAP-MWCNT nanocomposite having 3 wt% MWCNT. The optimum induced doping interaction of MWCNT with PmAP in terms of conductivity is explained on the basis of the above characterizations. The further increase in conductivity for the nanocomposites is observed by optimum sulfuric acid doping and highest conductivity is achieved as 1.03 Â 10 À3 S cm À1 for PmAP-MWCNT having 3 wt% MWCNT.
Carboxyl-functionalized multi-walled carbon nanotube (c-MWCNT) reinforced poly(m-aminophenol (PmA... more Carboxyl-functionalized multi-walled carbon nanotube (c-MWCNT) reinforced poly(m-aminophenol (PmAP) nanocomposite film was fabricated by in-situ chemical oxidation polymerization of m-aminophenol in presence of c-MWCNTs, and exploited it as an effective sensor material for detection of aliphatic alcohols. The presence site-selective interaction between the conjugated PmAP chain and the-bonded surface of c-MWCNT was confirmed by Fourier transform infrared (FT-IR) and Raman spectroscopy. The morphological analysis of the nanocomposite showed the formation of PmAP coating (thickness ∼100 nm) on the CNT surfaces. The X-ray and electron diffraction patterns of the nanocom-posites indicated the crystalline nature of the PmAP matrix. The nanocomposite with small quantity of c-MWCNT (2 wt%) was found to have sensing response about 114% and 96% higher than that of pure PmAP for methanol and ethanol vapor (90 ppm). This dramatic improvement of sensing performance might be attributed to the favorable interactions of c-MWCNTs with conjugated PmAP chains that subsequently generate a pathway for possible H-bonding/dipole interaction with the alcohol molecules. The nanocom-posite sensor also exhibits distinct features of the response curves and responsivity values for different aliphatic alcohols, which could be used as a basis for the selective detection of these pollutant vapors. The UV–vis and FT-IR analyses were used to explain the sensing mechanism.
Poly(m-aminophenol)-multi-walled carbon nanotube (PmAP-MWCNT) composites are successfully synthes... more Poly(m-aminophenol)-multi-walled carbon nanotube (PmAP-MWCNT) composites are successfully synthesized by in situ chemical oxidative polymerization of m-aminophenol (mAP) with varying amount of MWCNT dispersion in aqueous sodium hydroxide medium. All the synthesized PmAP-MWCNT nanocomposites are found to be soluble in organic solvent and well free standing film is cast from the solution. Different techniques like Fourier transform infrared spectro-scopy, ultraviolet visible spectroscopy, X-ray diffraction, scanning electron microscopy, and transmission electron microscopy are used to study the interaction between PmAP and MWCNT within their nanocomposite. Thermal stability of the synthesized nanocomposites is analyzed by thermogravi-metric analysis. Without any other type of further doping, the highest average DC-conductivity of 1.3 Â 10 À7 S cm À1 is recorded for the PmAP-MWCNT nanocomposite having 3 wt% MWCNT. The optimum induced doping interaction of MWCNT with PmAP in terms of conductivity is explained on the basis of the above characterizations. The further increase in conductivity for the nanocomposites is observed by optimum sulfuric acid doping and highest conductivity is achieved as 1.03 Â 10 À3 S cm À1 for PmAP-MWCNT having 3 wt% MWCNT.
Carboxyl-functionalized multi-walled carbon nanotube (c-MWCNT) reinforced poly(m-aminophenol (PmA... more Carboxyl-functionalized multi-walled carbon nanotube (c-MWCNT) reinforced poly(m-aminophenol (PmAP) nanocomposite film was fabricated by in-situ chemical oxidation polymerization of m-aminophenol in presence of c-MWCNTs, and exploited it as an effective sensor material for detection of aliphatic alcohols. The presence site-selective interaction between the conjugated PmAP chain and the-bonded surface of c-MWCNT was confirmed by Fourier transform infrared (FT-IR) and Raman spectroscopy. The morphological analysis of the nanocomposite showed the formation of PmAP coating (thickness ∼100 nm) on the CNT surfaces. The X-ray and electron diffraction patterns of the nanocom-posites indicated the crystalline nature of the PmAP matrix. The nanocomposite with small quantity of c-MWCNT (2 wt%) was found to have sensing response about 114% and 96% higher than that of pure PmAP for methanol and ethanol vapor (90 ppm). This dramatic improvement of sensing performance might be attributed to the favorable interactions of c-MWCNTs with conjugated PmAP chains that subsequently generate a pathway for possible H-bonding/dipole interaction with the alcohol molecules. The nanocom-posite sensor also exhibits distinct features of the response curves and responsivity values for different aliphatic alcohols, which could be used as a basis for the selective detection of these pollutant vapors. The UV–vis and FT-IR analyses were used to explain the sensing mechanism.
Core–shell carboxyl-functionalized multiwall carbon nanotube (c-MWCNT)/poly(m-aminophenol) (PmAP)... more Core–shell carboxyl-functionalized multiwall carbon nanotube (c-MWCNT)/poly(m-aminophenol) (PmAP) nanocom-posite were prepared through in-situ polymerization of m-aminophenol (mAP) in the presence of MWCNTs, and ex-plicated as a dielectric material for electronic applications. The formation of thin PmAP layer on individual c-MWCNT with excellent molecular level interactions at interfaces was confirmed by morphological and spectroscopic analyses. Here we conducted a comparative study of the dielectric performances of PmAP based nanocomposite films with pristine MWCNTs and c-MWCNTs as fillers. Compared to PmAP/MWCNT nanocomposites, the PmAP/c-MWCNT nanocomposites exhibited higher dielectric permittivity and lower dielectric loss. The well dispersed c-MWCNTs in PmAP/c-MWCNT nanocomposite produce huge interfacial area together with numerous active polarized centers (crystallographic defects), which in turn intensified the Maxwell-Wagner-Sillars (MWS) effect based on excellent molecular level interactions and thus, produce large dielectric permittivity (8810 at 1 kHz). The percolation threshold of PmAP/c-MWCNT nanocomposites is found lower than that of the PmAP/MWCNT nanocomposites, which could be attributed to homogeneous distribution of c-MWCNTs and strong c-MWCNT//PmAP interfacial interactions in the nanocomposites.
Journal of Applied Polymer Science, Nov 5, 2004
Skip to Main Content. ...
Mathematical Programming Series a and B, 2006
... Program., Ser. A 106, 391401 (2006) Ilan Adler · Richard W. Cottle · Sushil Verma Sufficient... more ... Program., Ser. A 106, 391401 (2006) Ilan Adler · Richard W. Cottle · Sushil Verma Sufficient matrices belong to L ... e-mail: sushil.verma@signaldemand.com Mathematics Subject Classification (2000): 90C33, 65K10, 15A99 Page 2. 392 I. Adler et al. ...