Carla Dalmolin | Universidade do Estado de Santa Catarina (original) (raw)
Papers by Carla Dalmolin
Materials research, 2024
This study investigated the impact of adding graphene oxide (GO) and iron oxide (II) (Fe 3 O 4) n... more This study investigated the impact of adding graphene oxide (GO) and iron oxide (II) (Fe 3 O 4) nanoparticles individually and in combination on the morphology, thermo-mechanical, and dielectric properties of a Polypropylene/High-Density Polyethylene (PP/HDPE) blend. By adding these nanoparticles separately or as a mixture, we can determine if both mechanisms have a synergistic effect and how they impact the dielectric constant values of their nanocomposites. The nanoparticle mixture was prepared in both an alkaline and a neutral medium. The mixture in the alkaline medium contained lower quantities of iron nanoparticles than in the neutral medium, and they were localized on the surface of GO. The nanocomposites showed significant differences in dynamic-mechanical and dielectric properties. The system with Fe 3 O 4 exhibited a higher storage modulus, while the system with GO had a higher dielectric constant. However, no synergistic effect was observed in the nanoparticle mixtures.
Materials Today Chemistry, 2021
Universidade Federal de São Carlos, Mar 22, 2006
Journal of Applied Polymer Science
Polyaniline is a conducting polymer that has recently been studied regarding its potential in the... more Polyaniline is a conducting polymer that has recently been studied regarding its potential in the removal of contaminants by heterogeneous photocatalysis. Since it is a polymer with a high absorption capacity of photons in the visible region, it promotes the photosensitization of catalysts that are typically inactive in solar systems. The increasing number of publications applying photocatalysis and composite catalysts based on polyaniline highlights the importance of this subject. This review systematizes the most important and specific contributions of composite catalysts formed by polyaniline. The main mechanisms proposed for photosensitization, which show the synergism between the phases of the composite, are summarized. Moreover, the relevance of morphology and conductivity of the composite catalyst, operating parameters (eg. pH, and light source contaminant) are some of the aspects discussed, revealing how these differ from traditional catalysts. Future prospects for the conti...
Materials Research, 2013
PHB was characterized after different industrial processes by Differential Scanning Calorimetry (... more PHB was characterized after different industrial processes by Differential Scanning Calorimetry (DSC), Fourier Transform Infrared Spectroscopy (FTIR), Melt Flow Index (MFI), Complex Dielectric Relaxation (CDR) and Size Exclusion Chromatography (SEC). Some properties of PHB were investigated before and after processing, in order to understand how temperature and other extrusion or injection conditions affect the polymer degradation. All the processed samples showed an increasing in the melt flow index, a decreasing of the dynamic crystallization temperature, and a reduction in the molar mass, suggesting some degradation. The molar mass reduction after processing, predicted when only thermal degradation is considered, was calculated in function of the kinetic parameters, such as constant thermal degradation and residence time during the industrial processing. It was found that the real molar mass reduction was higher than the theoretical value, indicating an important contribution of the shearing of polymeric chains during processing in the PHB degradation.
Carbon electrodes show the advantage in comparison to metal electrodes that they are chemically i... more Carbon electrodes show the advantage in comparison to metal electrodes that they are chemically inert and have a low impedance. Therefore, the aim of this work was to develop two impedance probes whose electrodes were based on carbon and to test their usability for the measurement of skin impedance. Knowing the passive electrical properties of skin is of importance e.g. for dosimetry purposes. The electrode material for one probe was graphite mixed into paraffin wax and for the other electrode carbon fibers that were glued together with silicone. The electrodes were formed concentric with an inner electrode and an outer ring electrode. Broadband frequency sweeps from 1 Hz to 1 MHz were conducted on the palm of the left hand of the author in a dry and a wet state. The impedance of dry skin at low frequencies lay above 100 kΩ, the high frequency value lay at a few hundred Ohms. One dominant dispersion could be observed. On wet skin a low frequency impedance in between 10 kΩ and 100 kΩ...
Macromolecular Symposia, 2020
Polyaniline is a conducting polymer that has recently been studied regarding its potential in the... more Polyaniline is a conducting polymer that has recently been studied regarding its potential in the removal of contaminants by heterogeneous photocatalysis. Since it is a polymer with a high absorption capacity of photons in the visible region, it promotes the photosensitization of catalysts that are typically inactive in solar systems. The increasing number of publications applying photocatalysis and composite catalysts based on polyaniline highlights the importance of this subject. This review systematizes the most important and specific contributions of composite catalysts formed by polyaniline. The main mechanisms proposed for photosensitization, which show the synergism between the phases of the composite, are summarized. Moreover, the relevance of morphology and conductivity of the composite catalyst, operating parameters (eg. pH, and light source contaminant) are some of the aspects discussed, revealing how these differ from traditional catalysts. Future prospects for the continuation and improvement of this issue mainly involve a greater variety of contaminant removal tests and understanding of relations between the structure of the material and its photocatalytic property.
Journal of Applied Polymer Science
Plasma Processes and Polymers
Journal of Applied Polymer Science
Journal of Polymer Engineering
An active screen plasma system (ASPS) was used for the surface activation of poly(lactic acid) (P... more An active screen plasma system (ASPS) was used for the surface activation of poly(lactic acid) (PLA) as a pretreatment before the oxidative graft polymerization of polyaniline (PANI). In ASPS, the plasma glow discharge occurs outside the grid, and the samples to be treated are placed inside the cage where they are subjected to a floating potential (about −12 V). An increase in hydrophilicity was observed for all samples after Ar plasma treatment. In addition, a decrease in thermal stability and changes in crystallization behavior were observed for PLA samples treated for a longer time. After PANI graft polymerization, smoothing of the surface topography was noticed in samples treated for short time periods. Such a change in the topography, in addition to surface activation, provides better conditions for subsequent PANI grafting.
Journal of Applied Polymer Science
Revista Processos Químicos
Visando oferecer uma alternativa ao tratamento de efl uentes com complexos orgânicos solúveis, co... more Visando oferecer uma alternativa ao tratamento de efl uentes com complexos orgânicos solúveis, conhecidos como BTEX, foi desenvolvida uma nanoestrutura adsorvente seletiva de complexos orgânicos com argila de capacidade de troca catiônica de origem brasileira a partir de técnicas de processamento de substâncias minerais. As nanoestruturas foram preparadas com a argila esmectitas vermelha (ArVe) ativada com carbonato de sódio e cloreto de hexadecil trimetilamônia. Foi observado que a variação na concentração de BETX em solução é proporcional à concentração da ArVe organofílica e que as isotemas de adsorção são aderentes aos modelos de Langmuir e Freundlich, com exceção do benzeno, que apresentou dispersão entre o modelo e os dados experimentais. Os tempos de residência para a saturação da ArVe organofílica e a velocidade inicial de adsorção para cada solvente foram obtidos através dos dados calculados para a cinética de pseudo 2ª ordem e pelas isotermas de adsorção. Os resultados ind...
Matéria (Rio de Janeiro)
Conducting polymers presents many potential applications such as biosensors and biofuelcells. How... more Conducting polymers presents many potential applications such as biosensors and biofuelcells. However, to be used in those devices, a thin film must be deposited onto a conducting and biocompatible substrate. In this work, carbon nanotubes (CNT) were mixed in a poly (lactic acid)-PLA-matrix with different compositions (from 0.25 to 5.0 %) in order to form conducting composites suitable to the deposition of a conducting polymer. Thermal properties of PLA/CNT composites were evaluated by Thermogravimetry (TG) and Differenctial Scanning Calorimetry (DSC), and the electrical properties were evaluated by 2-probe method and by Electrochemical Impedance Spectroscopy (EIS). Thermal analysis showed and influence of CNT quantities on PLA crystallization, which also showed an influence on conductivity of the tested materials. Besides, the conductivity of PLA/NTC 1% film showed similar values of the conducting polymer (Pani) itself.
Revista Virtual De Quimica, Nov 12, 2013
RVC/Conducting Polymer Electrodes for the design of an all-polymeric battery system The general p... more RVC/Conducting Polymer Electrodes for the design of an all-polymeric battery system The general purpose of this work is the optimization of the conducting polymer deposition on RVC and the use of these electrodes in an all-polymeric ion-lithium battery, which means an anode and a cathode made of conducting polymers. The high surface area of these materials influenced positively on the electrochemical behavior of the electrodes, leading to high-specific capacity electrodes when compared to similar bidimensional electrodes. Charge-discharge tests for batteries using RVC/polymer electrodes as the cathodic material showed similar or even higher specific capacities than the ones found in the literature. It is believed that the substrate's high surface area is the responsible for these findings, since it facilitates the redox reactions in the polymers. Introdução O interesse em produzir uma bateria toda polimérica é principalmente devido à baixa densidade dos polímeros e ao baixo impa...
Materials research, 2024
This study investigated the impact of adding graphene oxide (GO) and iron oxide (II) (Fe 3 O 4) n... more This study investigated the impact of adding graphene oxide (GO) and iron oxide (II) (Fe 3 O 4) nanoparticles individually and in combination on the morphology, thermo-mechanical, and dielectric properties of a Polypropylene/High-Density Polyethylene (PP/HDPE) blend. By adding these nanoparticles separately or as a mixture, we can determine if both mechanisms have a synergistic effect and how they impact the dielectric constant values of their nanocomposites. The nanoparticle mixture was prepared in both an alkaline and a neutral medium. The mixture in the alkaline medium contained lower quantities of iron nanoparticles than in the neutral medium, and they were localized on the surface of GO. The nanocomposites showed significant differences in dynamic-mechanical and dielectric properties. The system with Fe 3 O 4 exhibited a higher storage modulus, while the system with GO had a higher dielectric constant. However, no synergistic effect was observed in the nanoparticle mixtures.
Materials Today Chemistry, 2021
Universidade Federal de São Carlos, Mar 22, 2006
Journal of Applied Polymer Science
Polyaniline is a conducting polymer that has recently been studied regarding its potential in the... more Polyaniline is a conducting polymer that has recently been studied regarding its potential in the removal of contaminants by heterogeneous photocatalysis. Since it is a polymer with a high absorption capacity of photons in the visible region, it promotes the photosensitization of catalysts that are typically inactive in solar systems. The increasing number of publications applying photocatalysis and composite catalysts based on polyaniline highlights the importance of this subject. This review systematizes the most important and specific contributions of composite catalysts formed by polyaniline. The main mechanisms proposed for photosensitization, which show the synergism between the phases of the composite, are summarized. Moreover, the relevance of morphology and conductivity of the composite catalyst, operating parameters (eg. pH, and light source contaminant) are some of the aspects discussed, revealing how these differ from traditional catalysts. Future prospects for the conti...
Materials Research, 2013
PHB was characterized after different industrial processes by Differential Scanning Calorimetry (... more PHB was characterized after different industrial processes by Differential Scanning Calorimetry (DSC), Fourier Transform Infrared Spectroscopy (FTIR), Melt Flow Index (MFI), Complex Dielectric Relaxation (CDR) and Size Exclusion Chromatography (SEC). Some properties of PHB were investigated before and after processing, in order to understand how temperature and other extrusion or injection conditions affect the polymer degradation. All the processed samples showed an increasing in the melt flow index, a decreasing of the dynamic crystallization temperature, and a reduction in the molar mass, suggesting some degradation. The molar mass reduction after processing, predicted when only thermal degradation is considered, was calculated in function of the kinetic parameters, such as constant thermal degradation and residence time during the industrial processing. It was found that the real molar mass reduction was higher than the theoretical value, indicating an important contribution of the shearing of polymeric chains during processing in the PHB degradation.
Carbon electrodes show the advantage in comparison to metal electrodes that they are chemically i... more Carbon electrodes show the advantage in comparison to metal electrodes that they are chemically inert and have a low impedance. Therefore, the aim of this work was to develop two impedance probes whose electrodes were based on carbon and to test their usability for the measurement of skin impedance. Knowing the passive electrical properties of skin is of importance e.g. for dosimetry purposes. The electrode material for one probe was graphite mixed into paraffin wax and for the other electrode carbon fibers that were glued together with silicone. The electrodes were formed concentric with an inner electrode and an outer ring electrode. Broadband frequency sweeps from 1 Hz to 1 MHz were conducted on the palm of the left hand of the author in a dry and a wet state. The impedance of dry skin at low frequencies lay above 100 kΩ, the high frequency value lay at a few hundred Ohms. One dominant dispersion could be observed. On wet skin a low frequency impedance in between 10 kΩ and 100 kΩ...
Macromolecular Symposia, 2020
Polyaniline is a conducting polymer that has recently been studied regarding its potential in the... more Polyaniline is a conducting polymer that has recently been studied regarding its potential in the removal of contaminants by heterogeneous photocatalysis. Since it is a polymer with a high absorption capacity of photons in the visible region, it promotes the photosensitization of catalysts that are typically inactive in solar systems. The increasing number of publications applying photocatalysis and composite catalysts based on polyaniline highlights the importance of this subject. This review systematizes the most important and specific contributions of composite catalysts formed by polyaniline. The main mechanisms proposed for photosensitization, which show the synergism between the phases of the composite, are summarized. Moreover, the relevance of morphology and conductivity of the composite catalyst, operating parameters (eg. pH, and light source contaminant) are some of the aspects discussed, revealing how these differ from traditional catalysts. Future prospects for the continuation and improvement of this issue mainly involve a greater variety of contaminant removal tests and understanding of relations between the structure of the material and its photocatalytic property.
Journal of Applied Polymer Science
Plasma Processes and Polymers
Journal of Applied Polymer Science
Journal of Polymer Engineering
An active screen plasma system (ASPS) was used for the surface activation of poly(lactic acid) (P... more An active screen plasma system (ASPS) was used for the surface activation of poly(lactic acid) (PLA) as a pretreatment before the oxidative graft polymerization of polyaniline (PANI). In ASPS, the plasma glow discharge occurs outside the grid, and the samples to be treated are placed inside the cage where they are subjected to a floating potential (about −12 V). An increase in hydrophilicity was observed for all samples after Ar plasma treatment. In addition, a decrease in thermal stability and changes in crystallization behavior were observed for PLA samples treated for a longer time. After PANI graft polymerization, smoothing of the surface topography was noticed in samples treated for short time periods. Such a change in the topography, in addition to surface activation, provides better conditions for subsequent PANI grafting.
Journal of Applied Polymer Science
Revista Processos Químicos
Visando oferecer uma alternativa ao tratamento de efl uentes com complexos orgânicos solúveis, co... more Visando oferecer uma alternativa ao tratamento de efl uentes com complexos orgânicos solúveis, conhecidos como BTEX, foi desenvolvida uma nanoestrutura adsorvente seletiva de complexos orgânicos com argila de capacidade de troca catiônica de origem brasileira a partir de técnicas de processamento de substâncias minerais. As nanoestruturas foram preparadas com a argila esmectitas vermelha (ArVe) ativada com carbonato de sódio e cloreto de hexadecil trimetilamônia. Foi observado que a variação na concentração de BETX em solução é proporcional à concentração da ArVe organofílica e que as isotemas de adsorção são aderentes aos modelos de Langmuir e Freundlich, com exceção do benzeno, que apresentou dispersão entre o modelo e os dados experimentais. Os tempos de residência para a saturação da ArVe organofílica e a velocidade inicial de adsorção para cada solvente foram obtidos através dos dados calculados para a cinética de pseudo 2ª ordem e pelas isotermas de adsorção. Os resultados ind...
Matéria (Rio de Janeiro)
Conducting polymers presents many potential applications such as biosensors and biofuelcells. How... more Conducting polymers presents many potential applications such as biosensors and biofuelcells. However, to be used in those devices, a thin film must be deposited onto a conducting and biocompatible substrate. In this work, carbon nanotubes (CNT) were mixed in a poly (lactic acid)-PLA-matrix with different compositions (from 0.25 to 5.0 %) in order to form conducting composites suitable to the deposition of a conducting polymer. Thermal properties of PLA/CNT composites were evaluated by Thermogravimetry (TG) and Differenctial Scanning Calorimetry (DSC), and the electrical properties were evaluated by 2-probe method and by Electrochemical Impedance Spectroscopy (EIS). Thermal analysis showed and influence of CNT quantities on PLA crystallization, which also showed an influence on conductivity of the tested materials. Besides, the conductivity of PLA/NTC 1% film showed similar values of the conducting polymer (Pani) itself.
Revista Virtual De Quimica, Nov 12, 2013
RVC/Conducting Polymer Electrodes for the design of an all-polymeric battery system The general p... more RVC/Conducting Polymer Electrodes for the design of an all-polymeric battery system The general purpose of this work is the optimization of the conducting polymer deposition on RVC and the use of these electrodes in an all-polymeric ion-lithium battery, which means an anode and a cathode made of conducting polymers. The high surface area of these materials influenced positively on the electrochemical behavior of the electrodes, leading to high-specific capacity electrodes when compared to similar bidimensional electrodes. Charge-discharge tests for batteries using RVC/polymer electrodes as the cathodic material showed similar or even higher specific capacities than the ones found in the literature. It is believed that the substrate's high surface area is the responsible for these findings, since it facilitates the redox reactions in the polymers. Introdução O interesse em produzir uma bateria toda polimérica é principalmente devido à baixa densidade dos polímeros e ao baixo impa...