The Experts below are selected from a list of 3651 Experts worldwide ranked by ideXlab platform
Béla Iván - One of the best experts on this subject based on the ideXlab platform.
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cationic polymerization of styrene by the ticl4 n n n n tetramethylethylenediamine tmeda catalyst system in benzotrifluoride an environmentally Benign Solvent at room temperature
Polymer, 2012Co-Authors: Klára Verebélyi, Béla IvánAbstract:Abstract Highly efficient carbocationic polymerization of styrene was achieved under environmentally advantageous conditions in benzotrifluoride, BTF (α,α,α-trifluorotoluene, TFT), an environmentally Benign Solvent at room temperature, that is without any energy consumption for cooling or heating, with even better yields than that in the usually applied volatile and harmful, widely used chlorinated Solvent, dichloromethane (DCM). The polymerization was initiated by 1-phenylethyl chloride in conjunction with the TiCl4/TMEDA (N,N,N′,N′-tetramethylethylenediamine) catalyst (coinitiator) system. Within a very short reaction time (5 min), higher conversion values were obtained in BTF (89%) than in DCM (76%), that is the TiCl4/TMEDA combination proved to be a powerful catalyst for the carbocationic polymerization of styrene even in BTF. The molecular weight distributions of the synthesized polymers were relatively narrow in both Solvents (Mw/Mn = 1.29–1.65). The effect of the increasing reaction temperature (up to room temperature) was also investigated. With increasing reaction temperature, the polydispersity decreased and Mn close to the theoretical one was obtained in BTF at room temperature. Structural analysis with 1H NMR revealed that the major chain breaking reaction in this polymerization is indanyl ring formation between the penultimate monomer unit and the propagating carbocation. These results indicate that BTF can be utilized as a unique, inert, non-volatile, environment friendly Solvent with medium polarity for cationic polymerization of styrene, a nonfluorous monomer, and based on these results, presumably it may be also applied effectively as a quite universal Solvent for a large array of various polymerizations and copolymerizations for not only fluorinated, but also for nonflourous monomers, and other chemical reactions as well.
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Cationic polymerization of styrene by the TiCl4/N,N,N′,N′-tetramethylethylenediamine(TMEDA) catalyst system in benzotrifluoride, an environmentally Benign Solvent, at room temperature
Polymer, 2012Co-Authors: Klára Verebélyi, Béla IvánAbstract:Abstract Highly efficient carbocationic polymerization of styrene was achieved under environmentally advantageous conditions in benzotrifluoride, BTF (α,α,α-trifluorotoluene, TFT), an environmentally Benign Solvent at room temperature, that is without any energy consumption for cooling or heating, with even better yields than that in the usually applied volatile and harmful, widely used chlorinated Solvent, dichloromethane (DCM). The polymerization was initiated by 1-phenylethyl chloride in conjunction with the TiCl4/TMEDA (N,N,N′,N′-tetramethylethylenediamine) catalyst (coinitiator) system. Within a very short reaction time (5 min), higher conversion values were obtained in BTF (89%) than in DCM (76%), that is the TiCl4/TMEDA combination proved to be a powerful catalyst for the carbocationic polymerization of styrene even in BTF. The molecular weight distributions of the synthesized polymers were relatively narrow in both Solvents (Mw/Mn = 1.29–1.65). The effect of the increasing reaction temperature (up to room temperature) was also investigated. With increasing reaction temperature, the polydispersity decreased and Mn close to the theoretical one was obtained in BTF at room temperature. Structural analysis with 1H NMR revealed that the major chain breaking reaction in this polymerization is indanyl ring formation between the penultimate monomer unit and the propagating carbocation. These results indicate that BTF can be utilized as a unique, inert, non-volatile, environment friendly Solvent with medium polarity for cationic polymerization of styrene, a nonfluorous monomer, and based on these results, presumably it may be also applied effectively as a quite universal Solvent for a large array of various polymerizations and copolymerizations for not only fluorinated, but also for nonflourous monomers, and other chemical reactions as well.
Arumugam Gnanamani - One of the best experts on this subject based on the ideXlab platform.
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Collagen coated electrospun polycaprolactone (PCL) with titanium dioxide (TiO_2) from an environmentally Benign Solvent: preliminary physico-chemical studies for skin substitute
Journal of Polymer Research, 2014Co-Authors: Kajal Ghosal, Sabu Thomas, Nandakumar Kalarikkal, Arumugam GnanamaniAbstract:Fabrication of nanofibers with some biomaterials based on natural materials (collagen) through electrospinning is an important area for research. The effect of collagen coating on polycaprolactone (PCL) nanofiber surfaces was studied here. In this work, PCL nanofibers with titanium dioxide (TiO_2) nanopowder were used for the development of active wound dressings. We used glacial acetic acid as an environmentally Benign Solvent. The prepared nanofibers were coated with collagen by soaking the scaffold in 10 mg/mL and 20 mg/ml collagen solution overnight. The samples produced were subjected to contact angle measurements, SEM, FTIR, and XRD, and mechanical strength was determined. Nanofibers in the range of 200–800 nm were produced. The other study confirmed the physical interaction between collagen and PCL. The hydrophilicity of PCL nanofibers was increased; this was confirmed by observing contact angle values. A hydrophilic surface on the scaffold is necessary for biomedical applications. FTIR have proved the presence of an amide group on the PCL structure that facilitates cell adhesion and proliferation. SEM images have clearly proved the formation of nanofibers as well as the attachment of collagen to PCL nanofibers. XRD has shown the crystalline nature of the PCL polymer. PCL can impart more mechanical strength, although incorporation of collagen has decreased the tensile strength to some extent.
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Collagen coated electrospun polycaprolactone (PCL) with titanium dioxide (TiO_2) from an environmentally Benign Solvent: preliminary physico-chemical studies for skin substitute
Journal of Polymer Research, 2014Co-Authors: Kajal Ghosal, Sabu Thomas, Nandakumar Kalarikkal, Arumugam GnanamaniAbstract:Fabrication of nanofibers with some biomaterials based on natural materials (collagen) through electrospinning is an important area for research. The effect of collagen coating on polycaprolactone (PCL) nanofiber surfaces was studied here. In this work, PCL nanofibers with titanium dioxide (TiO_2) nanopowder were used for the development of active wound dressings. We used glacial acetic acid as an environmentally Benign Solvent. The prepared nanofibers were coated with collagen by soaking the scaffold in 10 mg/mL and 20 mg/ml collagen solution overnight. The samples produced were subjected to contact angle measurements, SEM, FTIR, and XRD, and mechanical strength was determined. Nanofibers in the range of 200–800 nm were produced. The other study confirmed the physical interaction between collagen and PCL. The hydrophilicity of PCL nanofibers was increased; this was confirmed by observing contact angle values. A hydrophilic surface on the scaffold is necessary for biomedical applications. FTIR have proved the presence of an amide group on the PCL structure that facilitates cell adhesion and proliferation. SEM images have clearly proved the formation of nanofibers as well as the attachment of collagen to PCL nanofibers. XRD has shown the crystalline nature of the PCL polymer. PCL can impart more mechanical strength, although incorporation of collagen has decreased the tensile strength to some extent.
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electrospinning of type i collagen and pcl nanofibers using acetic acid
Journal of Applied Polymer Science, 2012Co-Authors: Yogeshwar V Chakrapani, Arumugam Gnanamani, V R Giridev, M Madhusoothanan, G SekaranAbstract:Fabrication of nanofibrous biomaterials based on natural materials (collagen, gelatin, etc.) through various techniques is an important research topic. Electrospinning, a well-established technique for nanofiber production has also been extended for producing nanofibrous structures of natural materials. Collagen nanofiber production utilizes hexafluoro isopropanol (HFIP) as a Solvent for electrospinning. Research efforts are now focused on replacing HFIP with an environmentally Benign Solvent. In this study, electrospinning of Type I collagen of bovine skin with polycaprolactone (PCL) as a blend and an environmentally Benign Solvent, acetic acid, was carried out. The samples produced were subjected to contact angle measurements, porosity estimation, SEM, FTIR, TGA, and DSC. Nanofibers in the range of 100–200 nm were produced with an optimum porosity of 60%. The instrumental analyses confirm the physical interaction between collagen and PCL. Electrospinning of collagen in an environmentally Benign Solvent has been carried out and its usage in tissue engineering is being investigated by our research group. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Klára Verebélyi - One of the best experts on this subject based on the ideXlab platform.
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cationic polymerization of styrene by the ticl4 n n n n tetramethylethylenediamine tmeda catalyst system in benzotrifluoride an environmentally Benign Solvent at room temperature
Polymer, 2012Co-Authors: Klára Verebélyi, Béla IvánAbstract:Abstract Highly efficient carbocationic polymerization of styrene was achieved under environmentally advantageous conditions in benzotrifluoride, BTF (α,α,α-trifluorotoluene, TFT), an environmentally Benign Solvent at room temperature, that is without any energy consumption for cooling or heating, with even better yields than that in the usually applied volatile and harmful, widely used chlorinated Solvent, dichloromethane (DCM). The polymerization was initiated by 1-phenylethyl chloride in conjunction with the TiCl4/TMEDA (N,N,N′,N′-tetramethylethylenediamine) catalyst (coinitiator) system. Within a very short reaction time (5 min), higher conversion values were obtained in BTF (89%) than in DCM (76%), that is the TiCl4/TMEDA combination proved to be a powerful catalyst for the carbocationic polymerization of styrene even in BTF. The molecular weight distributions of the synthesized polymers were relatively narrow in both Solvents (Mw/Mn = 1.29–1.65). The effect of the increasing reaction temperature (up to room temperature) was also investigated. With increasing reaction temperature, the polydispersity decreased and Mn close to the theoretical one was obtained in BTF at room temperature. Structural analysis with 1H NMR revealed that the major chain breaking reaction in this polymerization is indanyl ring formation between the penultimate monomer unit and the propagating carbocation. These results indicate that BTF can be utilized as a unique, inert, non-volatile, environment friendly Solvent with medium polarity for cationic polymerization of styrene, a nonfluorous monomer, and based on these results, presumably it may be also applied effectively as a quite universal Solvent for a large array of various polymerizations and copolymerizations for not only fluorinated, but also for nonflourous monomers, and other chemical reactions as well.
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Cationic polymerization of styrene by the TiCl4/N,N,N′,N′-tetramethylethylenediamine(TMEDA) catalyst system in benzotrifluoride, an environmentally Benign Solvent, at room temperature
Polymer, 2012Co-Authors: Klára Verebélyi, Béla IvánAbstract:Abstract Highly efficient carbocationic polymerization of styrene was achieved under environmentally advantageous conditions in benzotrifluoride, BTF (α,α,α-trifluorotoluene, TFT), an environmentally Benign Solvent at room temperature, that is without any energy consumption for cooling or heating, with even better yields than that in the usually applied volatile and harmful, widely used chlorinated Solvent, dichloromethane (DCM). The polymerization was initiated by 1-phenylethyl chloride in conjunction with the TiCl4/TMEDA (N,N,N′,N′-tetramethylethylenediamine) catalyst (coinitiator) system. Within a very short reaction time (5 min), higher conversion values were obtained in BTF (89%) than in DCM (76%), that is the TiCl4/TMEDA combination proved to be a powerful catalyst for the carbocationic polymerization of styrene even in BTF. The molecular weight distributions of the synthesized polymers were relatively narrow in both Solvents (Mw/Mn = 1.29–1.65). The effect of the increasing reaction temperature (up to room temperature) was also investigated. With increasing reaction temperature, the polydispersity decreased and Mn close to the theoretical one was obtained in BTF at room temperature. Structural analysis with 1H NMR revealed that the major chain breaking reaction in this polymerization is indanyl ring formation between the penultimate monomer unit and the propagating carbocation. These results indicate that BTF can be utilized as a unique, inert, non-volatile, environment friendly Solvent with medium polarity for cationic polymerization of styrene, a nonfluorous monomer, and based on these results, presumably it may be also applied effectively as a quite universal Solvent for a large array of various polymerizations and copolymerizations for not only fluorinated, but also for nonflourous monomers, and other chemical reactions as well.
Kajal Ghosal - One of the best experts on this subject based on the ideXlab platform.
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Collagen coated electrospun polycaprolactone (PCL) with titanium dioxide (TiO_2) from an environmentally Benign Solvent: preliminary physico-chemical studies for skin substitute
Journal of Polymer Research, 2014Co-Authors: Kajal Ghosal, Sabu Thomas, Nandakumar Kalarikkal, Arumugam GnanamaniAbstract:Fabrication of nanofibers with some biomaterials based on natural materials (collagen) through electrospinning is an important area for research. The effect of collagen coating on polycaprolactone (PCL) nanofiber surfaces was studied here. In this work, PCL nanofibers with titanium dioxide (TiO_2) nanopowder were used for the development of active wound dressings. We used glacial acetic acid as an environmentally Benign Solvent. The prepared nanofibers were coated with collagen by soaking the scaffold in 10 mg/mL and 20 mg/ml collagen solution overnight. The samples produced were subjected to contact angle measurements, SEM, FTIR, and XRD, and mechanical strength was determined. Nanofibers in the range of 200–800 nm were produced. The other study confirmed the physical interaction between collagen and PCL. The hydrophilicity of PCL nanofibers was increased; this was confirmed by observing contact angle values. A hydrophilic surface on the scaffold is necessary for biomedical applications. FTIR have proved the presence of an amide group on the PCL structure that facilitates cell adhesion and proliferation. SEM images have clearly proved the formation of nanofibers as well as the attachment of collagen to PCL nanofibers. XRD has shown the crystalline nature of the PCL polymer. PCL can impart more mechanical strength, although incorporation of collagen has decreased the tensile strength to some extent.
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Collagen coated electrospun polycaprolactone (PCL) with titanium dioxide (TiO_2) from an environmentally Benign Solvent: preliminary physico-chemical studies for skin substitute
Journal of Polymer Research, 2014Co-Authors: Kajal Ghosal, Sabu Thomas, Nandakumar Kalarikkal, Arumugam GnanamaniAbstract:Fabrication of nanofibers with some biomaterials based on natural materials (collagen) through electrospinning is an important area for research. The effect of collagen coating on polycaprolactone (PCL) nanofiber surfaces was studied here. In this work, PCL nanofibers with titanium dioxide (TiO_2) nanopowder were used for the development of active wound dressings. We used glacial acetic acid as an environmentally Benign Solvent. The prepared nanofibers were coated with collagen by soaking the scaffold in 10 mg/mL and 20 mg/ml collagen solution overnight. The samples produced were subjected to contact angle measurements, SEM, FTIR, and XRD, and mechanical strength was determined. Nanofibers in the range of 200–800 nm were produced. The other study confirmed the physical interaction between collagen and PCL. The hydrophilicity of PCL nanofibers was increased; this was confirmed by observing contact angle values. A hydrophilic surface on the scaffold is necessary for biomedical applications. FTIR have proved the presence of an amide group on the PCL structure that facilitates cell adhesion and proliferation. SEM images have clearly proved the formation of nanofibers as well as the attachment of collagen to PCL nanofibers. XRD has shown the crystalline nature of the PCL polymer. PCL can impart more mechanical strength, although incorporation of collagen has decreased the tensile strength to some extent.
Nandakumar Kalarikkal - One of the best experts on this subject based on the ideXlab platform.
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Collagen coated electrospun polycaprolactone (PCL) with titanium dioxide (TiO_2) from an environmentally Benign Solvent: preliminary physico-chemical studies for skin substitute
Journal of Polymer Research, 2014Co-Authors: Kajal Ghosal, Sabu Thomas, Nandakumar Kalarikkal, Arumugam GnanamaniAbstract:Fabrication of nanofibers with some biomaterials based on natural materials (collagen) through electrospinning is an important area for research. The effect of collagen coating on polycaprolactone (PCL) nanofiber surfaces was studied here. In this work, PCL nanofibers with titanium dioxide (TiO_2) nanopowder were used for the development of active wound dressings. We used glacial acetic acid as an environmentally Benign Solvent. The prepared nanofibers were coated with collagen by soaking the scaffold in 10 mg/mL and 20 mg/ml collagen solution overnight. The samples produced were subjected to contact angle measurements, SEM, FTIR, and XRD, and mechanical strength was determined. Nanofibers in the range of 200–800 nm were produced. The other study confirmed the physical interaction between collagen and PCL. The hydrophilicity of PCL nanofibers was increased; this was confirmed by observing contact angle values. A hydrophilic surface on the scaffold is necessary for biomedical applications. FTIR have proved the presence of an amide group on the PCL structure that facilitates cell adhesion and proliferation. SEM images have clearly proved the formation of nanofibers as well as the attachment of collagen to PCL nanofibers. XRD has shown the crystalline nature of the PCL polymer. PCL can impart more mechanical strength, although incorporation of collagen has decreased the tensile strength to some extent.
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Collagen coated electrospun polycaprolactone (PCL) with titanium dioxide (TiO_2) from an environmentally Benign Solvent: preliminary physico-chemical studies for skin substitute
Journal of Polymer Research, 2014Co-Authors: Kajal Ghosal, Sabu Thomas, Nandakumar Kalarikkal, Arumugam GnanamaniAbstract:Fabrication of nanofibers with some biomaterials based on natural materials (collagen) through electrospinning is an important area for research. The effect of collagen coating on polycaprolactone (PCL) nanofiber surfaces was studied here. In this work, PCL nanofibers with titanium dioxide (TiO_2) nanopowder were used for the development of active wound dressings. We used glacial acetic acid as an environmentally Benign Solvent. The prepared nanofibers were coated with collagen by soaking the scaffold in 10 mg/mL and 20 mg/ml collagen solution overnight. The samples produced were subjected to contact angle measurements, SEM, FTIR, and XRD, and mechanical strength was determined. Nanofibers in the range of 200–800 nm were produced. The other study confirmed the physical interaction between collagen and PCL. The hydrophilicity of PCL nanofibers was increased; this was confirmed by observing contact angle values. A hydrophilic surface on the scaffold is necessary for biomedical applications. FTIR have proved the presence of an amide group on the PCL structure that facilitates cell adhesion and proliferation. SEM images have clearly proved the formation of nanofibers as well as the attachment of collagen to PCL nanofibers. XRD has shown the crystalline nature of the PCL polymer. PCL can impart more mechanical strength, although incorporation of collagen has decreased the tensile strength to some extent.