The Experts below are selected from a list of 1047 Experts worldwide ranked by ideXlab platform
Pedro Fardim - One of the best experts on this subject based on the ideXlab platform.
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topochemical engineering of composite hybrid fibers using layered double hydroxides and Abietic Acid
Beilstein Journal of Nanotechnology, 2019Co-Authors: S Liji S Sobhana, Lokesh Kesavan, Jan Gustafsson, Pedro FardimAbstract:Topochemical engineering of hybrid materials is an efficient way of synthesizing hydrophobic and highly tensile fiber composites by utilizing the intermolecular hydrogen bonds in natural materials. These materials include wood pulp fibers, Abietic Acid (resin Acid) and inexpensive metal salts. In this work, a hybrid composite was created using bleached and unbleached kraft pulp fibers as cellulose platform. In situ co-precipitation of layered double hydroxide (LDH) was performed to grow LDH crystals on the surface of the cellulose fibers, followed by the immobilization of Abietic Acid (AA) on LDH-grafted cellulose. Here we aimed to benefit from the hydrogen bonding between -OH groups of cellulose and LDH, and the -COOH groups of AA to obtain charge-directed assembly of one material on the other material. Thus, composite hybrid fibers (C-HF) were produced and then characterized by optical (CAM), spectroscopic (XRD, IR) and microscopic techniques (SEM) to determine their average length and distribution, structure and purity, bonding, and morphology. These fibers further were tested for water contact angle (hydrophobicity), oil absorption (lipophilicity), tensile strength and ISO brightness measurements. The performance of C-HF was compared with unmodified reference fibers (REF), fibers composed with only AA (C-F) and LDH-hybridized fibers (HF). The results revealed a variety of correlations between materials and their properties due to characteristic surface morphology, functional groups, hydrogen bonding and natural co-materials such as lignin and hemicelluloses. Attractive and repulsive van der Waals forces between material entities play a crucial role in the resulting properties.
Zhangfa Tong - One of the best experts on this subject based on the ideXlab platform.
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Nonisothermal Decomposition Kinetics of Abietic Acid in Argon Atmosphere
2016Co-Authors: Wei Jian Nong, Xiao Peng Chen, Jie Zhen Liang, Linlin Wang, Lingping Zhong, Zhangfa TongAbstract:Abietic Acid was isolated from rosin by means of reaction-crystallization coupled with exposure to ultrasonic waves, and it was then characterized by its specific rotation, infrared spectra, and 13C nuclear magnetic resonance spectra. The thermal decomposition of Abietic Acid in argon atmosphere was studied under nonisothermal conditions using TG-DTG techniques with heating rates of 5, 10, 20, and 25 K/min. For the kinetic study, the nonisothermal kinetic parameters were obtained via the analysis of the TG-DTG curves by using the Flynn-Wall-Ozawa (FWO) method, the Kissinger method, and the integral method. The results showed that the nonisothermal decomposition mechanism of Abietic Acid in argon atmosphere followed Mampel Power law with n = 3/2, whose differential and integral forms were f(α) = 2/3α–1/2 and G(α) = α3/2. The apparent activation energy Ea and the pre-exponential factor A were 123.44 kJ/mol and 1.78 × 1011 s–1, respectively. The kinetic equation can be expressed as dα/dt = 1.19 × 1011 α–1/2 exp(−1.48 × 104/T). The thermodynamic parameters (ΔH⧧, ΔG⧧, and ΔS⧧) were calculated as well
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measurement and correlation of solid liquid equilibrium for Abietic Acid alcohol systems at atmospheric pressure
Fluid Phase Equilibria, 2014Co-Authors: Wei Jian Nong, Xiao Peng Chen, Jie Zhen Liang, Linlin Wang, Hailing Wang, Liujin Long, Yanfen Huang, Zhangfa TongAbstract:Abstract Using a laser monitoring observation technique, the solubility of Abietic Acid in alcohols (isopropanol, isobutanol, 1-pentanol, isopentanol) has been measured by a dynamic method at atmospheric pressure. The melting point and enthalpy of fusion of Abietic Acid were determined by differential scanning calorimetry (DSC). The solubility of Abietic Acid in four solvents increased with an increase of temperature and the number of carbon atoms of alcohol chain, respectively. Experimental solubility data were correlated by means of the Wilson, NRTL and λh equations utilizing parameters derived from the related solid–liquid equilibrium (SLE) data. The results indicated that the above three equations are suitable for the description of the solubility data of Abietic Acid in the alcohols investigated.
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isolation and characterization of Abietic Acid
Advanced Materials Research, 2014Co-Authors: Wei Jian Nong, Xiao Peng Chen, Jie Zhen Liang, Linlin Wang, Zhangfa Tong, Ke Lin Huang, Qing Ruo Xie, Yan Hua JiaAbstract:Abietic Acid was isolated by means of isomerization and amination reaction-crystallization coupled with ultrasonic wave. Isomerization rosin and ethanolamine were used as raw materials, 95% ethanol as recrystallization solvent, the effects of reaction temperature, reaction time, agitating velocity, ultrasound intensity and recrystallization times on the purity and yield of Abietic Acid were investigated. The suitable isolation conditions were obtained as follow: reaction temperature 30 °C, reaction time 40 min, agitating velocity 400 rpm, ultrasound intensity 300 W and freeze crystallization of amine salt three times. The purity and yield of Abietic Acid were 98.52% and 54.93% when the suitable conditions were used. And it was then characterization by its melting point, specific rotation, UV, FTIR and NMR, all evidence indicated that the purification product was Abietic Acid.
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measurement and correlation of solubility of Abietic Acid in ethanol water mixtures
The Journal of Chemical Thermodynamics, 2014Co-Authors: Wei Jian Nong, Xiao Peng Chen, Jie Zhen Liang, Linlin Wang, Hailing Wang, Yingying Huang, Zhangfa TongAbstract:Abstract Using a laser monitoring observation technique, the solubility of Abietic Acid in (ethanol + water) mixtures was measured by a dynamic method at atmospheric pressure. The solubility of Abietic Acid increased with an increase of temperature and the concentration of ethanol. Experimental solubility data were correlated by means of the Wilson, NRTL and λh equations utilizing parameters derived from the (solid + liquid) equilibrium (SLE) data. The results showed that the three equations are suitable for description of the solubility data of Abietic Acid in the (ethanol + water) mixtures investigated.
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nonisothermal decomposition kinetics of Abietic Acid in argon atmosphere
Industrial & Engineering Chemistry Research, 2011Co-Authors: Wei Jian Nong, Xiao Peng Chen, Jie Zhen Liang, Linlin Wang, Lingping Zhong, Zhangfa TongAbstract:Abietic Acid was isolated from rosin by means of reaction-crystallization coupled with exposure to ultrasonic waves, and it was then characterized by its specific rotation, infrared spectra, and 13C nuclear magnetic resonance spectra. The thermal decomposition of Abietic Acid in argon atmosphere was studied under nonisothermal conditions using TG-DTG techniques with heating rates of 5, 10, 20, and 25 K/min. For the kinetic study, the nonisothermal kinetic parameters were obtained via the analysis of the TG-DTG curves by using the Flynn-Wall-Ozawa (FWO) method, the Kissinger method, and the integral method. The results showed that the nonisothermal decomposition mechanism of Abietic Acid in argon atmosphere followed Mampel Power law with n = 3/2, whose differential and integral forms were f(α) = 2/3α–1/2 and G(α) = α3/2. The apparent activation energy Ea and the pre-exponential factor A were 123.44 kJ/mol and 1.78 × 1011 s–1, respectively. The kinetic equation can be expressed as dα/dt = 1.19 × 1011α–1/2 e...
Wei Jian Nong - One of the best experts on this subject based on the ideXlab platform.
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Nonisothermal Decomposition Kinetics of Abietic Acid in Argon Atmosphere
2016Co-Authors: Wei Jian Nong, Xiao Peng Chen, Jie Zhen Liang, Linlin Wang, Lingping Zhong, Zhangfa TongAbstract:Abietic Acid was isolated from rosin by means of reaction-crystallization coupled with exposure to ultrasonic waves, and it was then characterized by its specific rotation, infrared spectra, and 13C nuclear magnetic resonance spectra. The thermal decomposition of Abietic Acid in argon atmosphere was studied under nonisothermal conditions using TG-DTG techniques with heating rates of 5, 10, 20, and 25 K/min. For the kinetic study, the nonisothermal kinetic parameters were obtained via the analysis of the TG-DTG curves by using the Flynn-Wall-Ozawa (FWO) method, the Kissinger method, and the integral method. The results showed that the nonisothermal decomposition mechanism of Abietic Acid in argon atmosphere followed Mampel Power law with n = 3/2, whose differential and integral forms were f(α) = 2/3α–1/2 and G(α) = α3/2. The apparent activation energy Ea and the pre-exponential factor A were 123.44 kJ/mol and 1.78 × 1011 s–1, respectively. The kinetic equation can be expressed as dα/dt = 1.19 × 1011 α–1/2 exp(−1.48 × 104/T). The thermodynamic parameters (ΔH⧧, ΔG⧧, and ΔS⧧) were calculated as well
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measurement and correlation of solid liquid equilibrium for Abietic Acid alcohol systems at atmospheric pressure
Fluid Phase Equilibria, 2014Co-Authors: Wei Jian Nong, Xiao Peng Chen, Jie Zhen Liang, Linlin Wang, Hailing Wang, Liujin Long, Yanfen Huang, Zhangfa TongAbstract:Abstract Using a laser monitoring observation technique, the solubility of Abietic Acid in alcohols (isopropanol, isobutanol, 1-pentanol, isopentanol) has been measured by a dynamic method at atmospheric pressure. The melting point and enthalpy of fusion of Abietic Acid were determined by differential scanning calorimetry (DSC). The solubility of Abietic Acid in four solvents increased with an increase of temperature and the number of carbon atoms of alcohol chain, respectively. Experimental solubility data were correlated by means of the Wilson, NRTL and λh equations utilizing parameters derived from the related solid–liquid equilibrium (SLE) data. The results indicated that the above three equations are suitable for the description of the solubility data of Abietic Acid in the alcohols investigated.
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isolation and characterization of Abietic Acid
Advanced Materials Research, 2014Co-Authors: Wei Jian Nong, Xiao Peng Chen, Jie Zhen Liang, Linlin Wang, Zhangfa Tong, Ke Lin Huang, Qing Ruo Xie, Yan Hua JiaAbstract:Abietic Acid was isolated by means of isomerization and amination reaction-crystallization coupled with ultrasonic wave. Isomerization rosin and ethanolamine were used as raw materials, 95% ethanol as recrystallization solvent, the effects of reaction temperature, reaction time, agitating velocity, ultrasound intensity and recrystallization times on the purity and yield of Abietic Acid were investigated. The suitable isolation conditions were obtained as follow: reaction temperature 30 °C, reaction time 40 min, agitating velocity 400 rpm, ultrasound intensity 300 W and freeze crystallization of amine salt three times. The purity and yield of Abietic Acid were 98.52% and 54.93% when the suitable conditions were used. And it was then characterization by its melting point, specific rotation, UV, FTIR and NMR, all evidence indicated that the purification product was Abietic Acid.
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measurement and correlation of solubility of Abietic Acid in ethanol water mixtures
The Journal of Chemical Thermodynamics, 2014Co-Authors: Wei Jian Nong, Xiao Peng Chen, Jie Zhen Liang, Linlin Wang, Hailing Wang, Yingying Huang, Zhangfa TongAbstract:Abstract Using a laser monitoring observation technique, the solubility of Abietic Acid in (ethanol + water) mixtures was measured by a dynamic method at atmospheric pressure. The solubility of Abietic Acid increased with an increase of temperature and the concentration of ethanol. Experimental solubility data were correlated by means of the Wilson, NRTL and λh equations utilizing parameters derived from the (solid + liquid) equilibrium (SLE) data. The results showed that the three equations are suitable for description of the solubility data of Abietic Acid in the (ethanol + water) mixtures investigated.
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nonisothermal decomposition kinetics of Abietic Acid in argon atmosphere
Industrial & Engineering Chemistry Research, 2011Co-Authors: Wei Jian Nong, Xiao Peng Chen, Jie Zhen Liang, Linlin Wang, Lingping Zhong, Zhangfa TongAbstract:Abietic Acid was isolated from rosin by means of reaction-crystallization coupled with exposure to ultrasonic waves, and it was then characterized by its specific rotation, infrared spectra, and 13C nuclear magnetic resonance spectra. The thermal decomposition of Abietic Acid in argon atmosphere was studied under nonisothermal conditions using TG-DTG techniques with heating rates of 5, 10, 20, and 25 K/min. For the kinetic study, the nonisothermal kinetic parameters were obtained via the analysis of the TG-DTG curves by using the Flynn-Wall-Ozawa (FWO) method, the Kissinger method, and the integral method. The results showed that the nonisothermal decomposition mechanism of Abietic Acid in argon atmosphere followed Mampel Power law with n = 3/2, whose differential and integral forms were f(α) = 2/3α–1/2 and G(α) = α3/2. The apparent activation energy Ea and the pre-exponential factor A were 123.44 kJ/mol and 1.78 × 1011 s–1, respectively. The kinetic equation can be expressed as dα/dt = 1.19 × 1011α–1/2 e...
Brigitte Stofer Vogel - One of the best experts on this subject based on the ideXlab platform.
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diterpenoid resin Acid biosynthesis in conifers enzymatic cyclization of geranylgeranyl pyrophosphate to abietadiene the precursor of Abietic Acid
Archives of Biochemistry and Biophysics, 1994Co-Authors: R E Lafever, Brigitte Stofer VogelAbstract:Abstract Abietic Acid is a major component of the rosin fraction of oleoresin synthesized by conifer species, such as grand fir (Abies grandis) and lodgepole pine (Pinus contorta), as a defensive secretion against insect and pathogen attack. This diterpenoid resin Acid is derived from geranylgeranyl pyrophosphate by conversion to abietadiene and sequential oxidation of the C18-methyl group of the precursor olefin to a carboxyl function. Resin Acid biosynthesis is constitutively expressed at high levels in lodgepole pine stem and is induced to these levels by stem wounding in grand fir. Soluble enzyme extracts of lodgepole pine stem and of mechanically wounded grand fir stem catalyzed the divalent metal ion-dependent cyclization of [1-3H]geranylgeranyl pyrophosphate to (−)-abieta-7(8),13(14)-diene. The wound-inducible enzyme was partially purified and identified as an 80-kDa protein with general characteristics typical of those of other terpenoid cyclases. Although the enzymatic cyclization sequence almost certainly involves the formation of copalyl pyrophosphate and a pimaradiene as stable intermediates, no evidence for the separation of the corresponding partial activities was obtained. A pathway involving the production of various pimaradiene and abietadiene isomers is proposed to account for the origin of several common resin Acids.
Iolanda Francolini - One of the best experts on this subject based on the ideXlab platform.
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intermolecular interaction and solid state characterization of Abietic Acid chitosan solid dispersions possessing antimicrobial and antioxidant properties
European Journal of Pharmaceutics and Biopharmaceutics, 2018Co-Authors: Valentina Cuzzucoli Crucitti, Luisa Maria Migneco, Antonella Piozzi, Vincenzo Taresco, Martin C Garnett, Richard H Argent, Iolanda FrancoliniAbstract:The aim of this work was to prepare and characterize solid dispersions of Abietic Acid (AB) and chitosan (CS) to investigate how formulation of the mixture may help in the battle against microbial colonization in different areas, such as the biomedical field or the food industry. Solid dispersions were characterized by differential scanning calorimetry, infrared spectroscopy, Raman spectroscopy, polarized optical microscopy, zeta potential and size analysis. The data showed that the dispersion/solvent evaporation method formed solid dispersions in which Abietic Acid was molecularly dispersed in the carrier. A synergistic effect between the two components in terms of antioxidant and antimicrobial properties was found, especially in the formulations obtained with 1/1 AB/CS molar ratio. Interestingly, the aggregation state (amorphous/crystalline) of AB seemed to affect the antimicrobial activity of the formulation, suggesting increased bioactivity when the drug was in the amorphous state. These findings, together with the demonstrated biocompatibility of the formulations, seem to open promising perspectives for a successful application of the developed AB/CS formulations in the biomedical field or in the food industry.
