S. B. Rekik, S. Gassara, J. Bouaziz, S. Baklouti, A. Deratani
This paper presents the successful preparation of porous membranes based on chitosan with enhanced mechanical, thermal and chemical properties applicable in water treatment field. Herein, chitosan/kaolin composite membranes with a cross-linking agent and a porogen were prepared using the solvent casting method. The characterization of the as-fabricated membranes indicated that the combined effect of kaolin as reinforcing agent, polyethylene glycol as pore former and citric acid as cross-linker in a chitosan matrix showed a significant influence on the membrane properties. The results indicated that the incorporation of a hydrophilic porogenic reagent into the collodion in addition to providing a porous morphology makes it possible to obtain a more hydrophilic membrane, and thus induces an increase in the pure water permeability. The cross-linked membranes exhibited an improved water resistance, better thermal and mechanical properties as compared to neat chitosan films. The cross-linked membranes had a mean pore size of 50 nm falling in the range of ultrafiltration. Their functional properties were determined in terms of pure water filtration and molecular weight cut-off tests.
{"title":"Fabrication, Characterization and Permeation Studies of Ionically Cross-linked Chitosan/Kaolin Composite Membranes","authors":"S. B. Rekik, S. Gassara, J. Bouaziz, S. Baklouti, A. Deratani","doi":"10.3311/ppch.21253","DOIUrl":"https://doi.org/10.3311/ppch.21253","url":null,"abstract":"This paper presents the successful preparation of porous membranes based on chitosan with enhanced mechanical, thermal and chemical properties applicable in water treatment field. Herein, chitosan/kaolin composite membranes with a cross-linking agent and a porogen were prepared using the solvent casting method. The characterization of the as-fabricated membranes indicated that the combined effect of kaolin as reinforcing agent, polyethylene glycol as pore former and citric acid as cross-linker in a chitosan matrix showed a significant influence on the membrane properties. The results indicated that the incorporation of a hydrophilic porogenic reagent into the collodion in addition to providing a porous morphology makes it possible to obtain a more hydrophilic membrane, and thus induces an increase in the pure water permeability. The cross-linked membranes exhibited an improved water resistance, better thermal and mechanical properties as compared to neat chitosan films. The cross-linked membranes had a mean pore size of 50 nm falling in the range of ultrafiltration. Their functional properties were determined in terms of pure water filtration and molecular weight cut-off tests.","PeriodicalId":19922,"journal":{"name":"Periodica Polytechnica Chemical Engineering","volume":"19 1","pages":""},"PeriodicalIF":1.3,"publicationDate":"2023-03-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80123095","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The conversion of natural and unconventional gas into syngas is a crucial intermediate step in the production of various important chemicals and liquid fuels. The syngas generation step usually requires the largest capital investment of the process and may also be very energy intensive. Therefore, determining the most efficient method of converting feedstock into syngas of the correct H2:CO ratio is of significant importance. The aim of this work was to set design and performance targets for different H2:CO ratios (depending on the downstream requirements) in terms of the carbon efficiency (including CO2 utilization or emissions), water usage, and energy requirements. It was shown that the overall process for natural gas tri-reforming is limited by the enthalpy change (ΔH = 0) and this process was able to produce work. It was further shown that high syngas ratios not only require significant amounts of natural gas and oxygen but also emit CO2.
{"title":"Developing a Targeting Approach for Syngas Generation from Natural Gas","authors":"B. Patel, Bahizire Martin Mukeru","doi":"10.3311/ppch.21115","DOIUrl":"https://doi.org/10.3311/ppch.21115","url":null,"abstract":"The conversion of natural and unconventional gas into syngas is a crucial intermediate step in the production of various important chemicals and liquid fuels. The syngas generation step usually requires the largest capital investment of the process and may also be very energy intensive. Therefore, determining the most efficient method of converting feedstock into syngas of the correct H2:CO ratio is of significant importance. The aim of this work was to set design and performance targets for different H2:CO ratios (depending on the downstream requirements) in terms of the carbon efficiency (including CO2 utilization or emissions), water usage, and energy requirements. It was shown that the overall process for natural gas tri-reforming is limited by the enthalpy change (ΔH = 0) and this process was able to produce work. It was further shown that high syngas ratios not only require significant amounts of natural gas and oxygen but also emit CO2.","PeriodicalId":19922,"journal":{"name":"Periodica Polytechnica Chemical Engineering","volume":"104 1","pages":""},"PeriodicalIF":1.3,"publicationDate":"2023-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85783926","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
I. Syaichurrozi, S. Sarto, W. B. Sediawan, M. Hidayat
Vinasse is a continuously resulting waste by a bioethanol industry with a high chemical oxygen demand (COD) concentration and a large volume. Anaerobic digestion (AD) is the best method to treat vinasse because it converts COD to biogas, so the biogas can support the Indonesia's primary energy need. The goal of this study was to study the effect of Fe concentration on the AD process in treating the vinasse. The Fe concentration was varied to 0.06, 0.29, 0.64, 0.99 g/L. The results showed that increasing the Fe concentration from 0.06 to 0.29 g/L intensified the biogas yield by 360% (from 10.8 to 49.6 mL/g COD). However, further increasing the Fe concentration to 0.99 g/L decreased the biogas yield by 37.8% (from 10.8 to 6.7 mL/g COD). The Fe significantly affected the methane formation stage, but not the acid formation stage. A mechanistic model was built and successfully applied to predict the AD process. Based on the simulation results, Fe concentration of 0.29 g/L resulted in the highest values of YVFA/X2 (yield of volatile fatty acids (VFAs) consumption per biomass of X2 ), μm,2 (specific growth rate for X2 ), fCH4 (composition of methane in biogas) and the lowest values of Ks,VFA (affinity coefficient in VFAs consumption), kd2 (death rate constant for X2 ), kVFA (consumption rate of VFAs for maintenance). The addition of Fe until 0.29 g/L was recommended to increase the quantity and quality (methane content reached 53.4%) of biogas production.
{"title":"Effect of Fe Addition on Anaerobic Digestion Process in Treating Vinasse: Experimental and Kinetic Studies","authors":"I. Syaichurrozi, S. Sarto, W. B. Sediawan, M. Hidayat","doi":"10.3311/ppch.20611","DOIUrl":"https://doi.org/10.3311/ppch.20611","url":null,"abstract":"Vinasse is a continuously resulting waste by a bioethanol industry with a high chemical oxygen demand (COD) concentration and a large volume. Anaerobic digestion (AD) is the best method to treat vinasse because it converts COD to biogas, so the biogas can support the Indonesia's primary energy need. The goal of this study was to study the effect of Fe concentration on the AD process in treating the vinasse. The Fe concentration was varied to 0.06, 0.29, 0.64, 0.99 g/L. The results showed that increasing the Fe concentration from 0.06 to 0.29 g/L intensified the biogas yield by 360% (from 10.8 to 49.6 mL/g COD). However, further increasing the Fe concentration to 0.99 g/L decreased the biogas yield by 37.8% (from 10.8 to 6.7 mL/g COD). The Fe significantly affected the methane formation stage, but not the acid formation stage. A mechanistic model was built and successfully applied to predict the AD process. Based on the simulation results, Fe concentration of 0.29 g/L resulted in the highest values of YVFA/X2 (yield of volatile fatty acids (VFAs) consumption per biomass of X2 ), μm,2 (specific growth rate for X2 ), fCH4 (composition of methane in biogas) and the lowest values of Ks,VFA (affinity coefficient in VFAs consumption), kd2 (death rate constant for X2 ), kVFA (consumption rate of VFAs for maintenance). The addition of Fe until 0.29 g/L was recommended to increase the quantity and quality (methane content reached 53.4%) of biogas production.","PeriodicalId":19922,"journal":{"name":"Periodica Polytechnica Chemical Engineering","volume":"18 1","pages":""},"PeriodicalIF":1.3,"publicationDate":"2023-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82701056","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The number of the cyclodextrin-containing drug formulations on the market has been continuously growing since the first drug (prostaglandin E1 formulated with α-cyclodextrin) was launched in Japan in 1976. We have collected a list of drugs from various sources available on the internet to find 130 approved pharmaceutical ingredients formulated with either parent cyclodextrins or their hydroxypropyl, sulfobutyl, random methylated or sulfolipo derivatives. We have sorted the drug products according to the cavity size of the cyclodextrins, the administration route and dosage forms.
{"title":"Recent List of Cyclodextrin-Containing Drug Products","authors":"I. Puskás, L. Szente, Levente Szőcs, É. Fenyvesi","doi":"10.3311/ppch.21222","DOIUrl":"https://doi.org/10.3311/ppch.21222","url":null,"abstract":"The number of the cyclodextrin-containing drug formulations on the market has been continuously growing since the first drug (prostaglandin E1 formulated with α-cyclodextrin) was launched in Japan in 1976. We have collected a list of drugs from various sources available on the internet to find 130 approved pharmaceutical ingredients formulated with either parent cyclodextrins or their hydroxypropyl, sulfobutyl, random methylated or sulfolipo derivatives. We have sorted the drug products according to the cavity size of the cyclodextrins, the administration route and dosage forms.","PeriodicalId":19922,"journal":{"name":"Periodica Polytechnica Chemical Engineering","volume":"75 2 1","pages":""},"PeriodicalIF":1.3,"publicationDate":"2023-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75845209","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
D. B. Kautsar, M. F. Rois, Nurul Faizah, W. Widiyastuti, T. Nurtono, H. Setyawan
In this work, the objective is to utilize avocado seed extract as a cheap alternative source of active compounds and was successfully encapsulated using gum arabic by spray drying as an antioxidant and antimicrobial agent. First, the active compounds were extracted from avocado seed using solvent n-hexane and followed by solvent separation using rotary vacuum evaporator. Next, gum arabic as the encapsulation agent was added to avocado seed extract to form an emulsion, then spray-dried with drying air at a temperature of 140 °C. The mass ratio of avocado seed was varied at extract: gum arabic of 5:5, 5:10, 5:15, and 5:20. Then, the particle morphology, yield, moisture content, encapsulation efficiency, loading capacity, chemical groups, antioxidant activity, and antibacterial ability were analyzed to investigate the performance of the encapsulation particles. Among the ranges studied, the extract–gum arabic with a mass ratio of 5:10 exhibited the best properties of yield powder, loading capacity, and encapsulation efficiency at 49.78%, 3.43%, and 7.33%, respectively. The encapsulated particles have smooth surface, crackless, lower indentation, and a single-core encapsulation structure with an average diameter of 4.60 μm. Besides, the stability of antioxidant activity decreased by 2.36%, from 94.82% to 92.46% for four weeks of storage. They also performed antimicrobial activity against E. coli and S. aureus, which were maintained after seven days. Meanwhile for avocado seed extract only, the unencapsulated stability of antioxidant activity has continually decrease from 91.58% to 84.05% and performed no antimicrobial activity against E. coli after seven days.
{"title":"Antioxidant and Antimicrobial Agents from Avocado (Persea americana) Seed Extract Encapsulated in Gum Arabic through Spray Drying Method","authors":"D. B. Kautsar, M. F. Rois, Nurul Faizah, W. Widiyastuti, T. Nurtono, H. Setyawan","doi":"10.3311/ppch.20698","DOIUrl":"https://doi.org/10.3311/ppch.20698","url":null,"abstract":"In this work, the objective is to utilize avocado seed extract as a cheap alternative source of active compounds and was successfully encapsulated using gum arabic by spray drying as an antioxidant and antimicrobial agent. First, the active compounds were extracted from avocado seed using solvent n-hexane and followed by solvent separation using rotary vacuum evaporator. Next, gum arabic as the encapsulation agent was added to avocado seed extract to form an emulsion, then spray-dried with drying air at a temperature of 140 °C. The mass ratio of avocado seed was varied at extract: gum arabic of 5:5, 5:10, 5:15, and 5:20. Then, the particle morphology, yield, moisture content, encapsulation efficiency, loading capacity, chemical groups, antioxidant activity, and antibacterial ability were analyzed to investigate the performance of the encapsulation particles. Among the ranges studied, the extract–gum arabic with a mass ratio of 5:10 exhibited the best properties of yield powder, loading capacity, and encapsulation efficiency at 49.78%, 3.43%, and 7.33%, respectively. The encapsulated particles have smooth surface, crackless, lower indentation, and a single-core encapsulation structure with an average diameter of 4.60 μm. Besides, the stability of antioxidant activity decreased by 2.36%, from 94.82% to 92.46% for four weeks of storage. They also performed antimicrobial activity against E. coli and S. aureus, which were maintained after seven days. Meanwhile for avocado seed extract only, the unencapsulated stability of antioxidant activity has continually decrease from 91.58% to 84.05% and performed no antimicrobial activity against E. coli after seven days.","PeriodicalId":19922,"journal":{"name":"Periodica Polytechnica Chemical Engineering","volume":"172 1","pages":""},"PeriodicalIF":1.3,"publicationDate":"2023-01-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76673468","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Multivariate image analysis quantitative structure-activity relationship (MIA-QSAR) study aims to obtain information from a descriptor set, which are image pixels of two-dimensional molecule structures. In the QSAR study of protein P38 mitogen-activated protein (MAP) kinase compounds, the genetic algorithm application for pixel selection and image processing is investigated. There is a quantitative relationship between the structure and the pIC50 based on the information obtained. (The pIC50 is the negative logarithm of the half-maximal inhibitory concentration ( IC50 ), so pIC50 = −log IC50 .) Protein P38 MAP kinase inhibitors are used in the treatment of malignant tumors. The development of a model to predict the pIC50 of these compounds was performed in this study. To accomplish this, the molecules were first plotted and fixed in the same coordinates in ChemSketch. Then, the images were processed in the MATLAB program. Partial least squares (PLS) model, orthogonal signal correction partial least squares (OSC-PLS) model, and genetic algorithm partial least squares (GA-PLS) model methods are used to generate quantitative models, and pIC50 prediction is performed. The GA-PLS model has the highest predictive power for a series of statistical parameters such as root mean square error of prediction (RMSEP) and relative standard errors of prediction (RSEP). Finally, the molecular junction (docking) was done for predicted molecules in quantitative structure activity relationship (QSAR) with an appropriate receptor and acceptable results were obtained. These results are good and proper for the prediction of compounds with better properties.
{"title":"Application of MIA-QSAR in Designing New Protein P38 MAP Kinase Compounds Using a Genetic Algorithm","authors":"Mithra Mirshafiei, A. Niazi, A. Yazdanipour","doi":"10.3311/ppch.20852","DOIUrl":"https://doi.org/10.3311/ppch.20852","url":null,"abstract":"Multivariate image analysis quantitative structure-activity relationship (MIA-QSAR) study aims to obtain information from a descriptor set, which are image pixels of two-dimensional molecule structures. In the QSAR study of protein P38 mitogen-activated protein (MAP) kinase compounds, the genetic algorithm application for pixel selection and image processing is investigated. There is a quantitative relationship between the structure and the pIC50 based on the information obtained. (The pIC50 is the negative logarithm of the half-maximal inhibitory concentration ( IC50 ), so pIC50 = −log IC50 .) Protein P38 MAP kinase inhibitors are used in the treatment of malignant tumors. The development of a model to predict the pIC50 of these compounds was performed in this study. To accomplish this, the molecules were first plotted and fixed in the same coordinates in ChemSketch. Then, the images were processed in the MATLAB program. Partial least squares (PLS) model, orthogonal signal correction partial least squares (OSC-PLS) model, and genetic algorithm partial least squares (GA-PLS) model methods are used to generate quantitative models, and pIC50 prediction is performed. The GA-PLS model has the highest predictive power for a series of statistical parameters such as root mean square error of prediction (RMSEP) and relative standard errors of prediction (RSEP). Finally, the molecular junction (docking) was done for predicted molecules in quantitative structure activity relationship (QSAR) with an appropriate receptor and acceptable results were obtained. These results are good and proper for the prediction of compounds with better properties.","PeriodicalId":19922,"journal":{"name":"Periodica Polytechnica Chemical Engineering","volume":"43 1 1","pages":""},"PeriodicalIF":1.3,"publicationDate":"2023-01-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88848213","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Balázs Lévai, Gábor Varró, A. Simon, L. Hegedűs, I. Kádas
An efficient stereoselective synthesis of a pivotal intermediate, a cyclic allyl alcohol derivative containing two methoxy groups [(±)-22], using for the preparation of (±)-trans-dihydronarciclasine analogues was elaborated starting from easily available and inexpensive methyl gallate. This new synthetic route consists of 17 reaction steps, and provides an opportunity to obtain the wanted alkaloid derivative containing an additional methoxy group at position 11, in the ring A of the phenanthridone scaffold.
{"title":"Stereoselective Synthesis of Novel (±)-trans-Dihydronarciclasine Analogues: Preparation of a Pivotal Intermediate Containing Two Methoxy Substituents","authors":"Balázs Lévai, Gábor Varró, A. Simon, L. Hegedűs, I. Kádas","doi":"10.3311/ppch.20438","DOIUrl":"https://doi.org/10.3311/ppch.20438","url":null,"abstract":"An efficient stereoselective synthesis of a pivotal intermediate, a cyclic allyl alcohol derivative containing two methoxy groups [(±)-22], using for the preparation of (±)-trans-dihydronarciclasine analogues was elaborated starting from easily available and inexpensive methyl gallate. This new synthetic route consists of 17 reaction steps, and provides an opportunity to obtain the wanted alkaloid derivative containing an additional methoxy group at position 11, in the ring A of the phenanthridone scaffold.","PeriodicalId":19922,"journal":{"name":"Periodica Polytechnica Chemical Engineering","volume":"28 1","pages":""},"PeriodicalIF":1.3,"publicationDate":"2023-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77322145","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Petra Tőzsér, Luca L. Kovács, Szabina Kádár, Dóra Csicsák, P. Sóti, Gergely Völgyi, B. Sinkó, Z. Nagy, Enikő Borbás
Solubility and permeability are key parameters for establishing in vitro-in vivo correlation for poorly water-soluble active pharmaceutical ingredients (APIs). Recent studies demonstrate that not only solubility, but also effective permeability of the API may change due to the addition of solubilizing agents, and there is a certain mathematical relation between these physicochemical parameters. The aim of this study was to show the importance of early screening of solubility and permeability in presence of additives in order to achieve the expected bioavailability of the API. In this work, the effect of surfactants and microenvironmental pH modifiers were in focus, and pimobendan was chosen as model drug.In the case of pH modifiers, the equilibrium solubility of the API increased, while the permeability decreased significantly. No negative effect was observed for two surfactants at low additive levels, but these two additives also exhibited a slightly negative effect on permeability when used at higher concentrations. In the simultaneous dissolution-permeation studies the surfactants-containing formulation was found to have slightly higher flux than the pH-modifier-containing one. It can be due to the phenomenon that the dissolution of the active substance can be enhanced by these surfactants without any significant permeability reducing effect.The results obtained from the present study clearly demonstrate the importance of studying drug-additive interactions in every step of formulation development and based on these, the selection of the appropriate quality and quantity of additives. In addition, the results also underline the significance of performing simultaneous dissolution-permeation studies to predict bioavailability.
{"title":"The Effect of Surfactants and pH Modifying Agents on the Dissolution and Permeation of Pimobendan","authors":"Petra Tőzsér, Luca L. Kovács, Szabina Kádár, Dóra Csicsák, P. Sóti, Gergely Völgyi, B. Sinkó, Z. Nagy, Enikő Borbás","doi":"10.3311/ppch.20970","DOIUrl":"https://doi.org/10.3311/ppch.20970","url":null,"abstract":"Solubility and permeability are key parameters for establishing in vitro-in vivo correlation for poorly water-soluble active pharmaceutical ingredients (APIs). Recent studies demonstrate that not only solubility, but also effective permeability of the API may change due to the addition of solubilizing agents, and there is a certain mathematical relation between these physicochemical parameters. The aim of this study was to show the importance of early screening of solubility and permeability in presence of additives in order to achieve the expected bioavailability of the API. In this work, the effect of surfactants and microenvironmental pH modifiers were in focus, and pimobendan was chosen as model drug.In the case of pH modifiers, the equilibrium solubility of the API increased, while the permeability decreased significantly. No negative effect was observed for two surfactants at low additive levels, but these two additives also exhibited a slightly negative effect on permeability when used at higher concentrations. In the simultaneous dissolution-permeation studies the surfactants-containing formulation was found to have slightly higher flux than the pH-modifier-containing one. It can be due to the phenomenon that the dissolution of the active substance can be enhanced by these surfactants without any significant permeability reducing effect.The results obtained from the present study clearly demonstrate the importance of studying drug-additive interactions in every step of formulation development and based on these, the selection of the appropriate quality and quantity of additives. In addition, the results also underline the significance of performing simultaneous dissolution-permeation studies to predict bioavailability.","PeriodicalId":19922,"journal":{"name":"Periodica Polytechnica Chemical Engineering","volume":"102 1","pages":""},"PeriodicalIF":1.3,"publicationDate":"2023-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89297323","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this study, we synthesized hexagonal boron nitride nanosheets (h-BNN) via the molten hydroxide exfoliation method which results in small flakes and nanoscrolls. The resultant h-BNNs can be dispersed in various solvents such as water, ethanol, and acetone, and form a stable dispersion. The morphological and structural analysis of h-BNNs were performed with Fourier Transform infrared spectroscopy (FTIR), X-ray diffractometry (XRD), and scanning electron microscopy (SEM). The masterbatch (MB) method was used to incorporate the h-BNNs into the polypropylene (PP) matrix via melt mixing. Dilution and film production processes were performed using a twin screw extruder. Nanocomposite films having an h-BNN weight ratio of 1%, 2%, 3%, and 5% were prepared. Thermogravimetric analyzer (TGA) and differential scanning calorimetry (DSC) were used to investigate the thermal stability. Crystallization (Tc) temperatures were increased with the increased amount of h-BNNs and h-BNNs nucleating agent behavior on the PP crystallization was observed. Oxidation induction time (OIT) of the pure PP was increased from 8.84 min to 17.82 min. The results show a considerable effect of the h-BNN content on the thermo-oxidative stability of the nanocomposites studied. The rheological and mechanical properties of the PP-hBNN nanocomposite films were also determined depending on the particle loading ratio. Optimum particle content providing the best thermal, mechanical, and rheological properties were found to be 3% wt.
{"title":"Processing and Characterization of Polypropylene Nanocomposite Films Reinforced with Hexagonal Boron Nitride Nanosheets","authors":"G. Bayramoglu, Mehmet Mudu","doi":"10.3311/ppch.20589","DOIUrl":"https://doi.org/10.3311/ppch.20589","url":null,"abstract":"In this study, we synthesized hexagonal boron nitride nanosheets (h-BNN) via the molten hydroxide exfoliation method which results in small flakes and nanoscrolls. The resultant h-BNNs can be dispersed in various solvents such as water, ethanol, and acetone, and form a stable dispersion. The morphological and structural analysis of h-BNNs were performed with Fourier Transform infrared spectroscopy (FTIR), X-ray diffractometry (XRD), and scanning electron microscopy (SEM). The masterbatch (MB) method was used to incorporate the h-BNNs into the polypropylene (PP) matrix via melt mixing. Dilution and film production processes were performed using a twin screw extruder. Nanocomposite films having an h-BNN weight ratio of 1%, 2%, 3%, and 5% were prepared. Thermogravimetric analyzer (TGA) and differential scanning calorimetry (DSC) were used to investigate the thermal stability. Crystallization (Tc) temperatures were increased with the increased amount of h-BNNs and h-BNNs nucleating agent behavior on the PP crystallization was observed. Oxidation induction time (OIT) of the pure PP was increased from 8.84 min to 17.82 min. The results show a considerable effect of the h-BNN content on the thermo-oxidative stability of the nanocomposites studied. The rheological and mechanical properties of the PP-hBNN nanocomposite films were also determined depending on the particle loading ratio. Optimum particle content providing the best thermal, mechanical, and rheological properties were found to be 3% wt.","PeriodicalId":19922,"journal":{"name":"Periodica Polytechnica Chemical Engineering","volume":"41 1","pages":""},"PeriodicalIF":1.3,"publicationDate":"2023-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85203843","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The sensing of formaldehyde, one of the volatile organic compounds used in chemical processes, is very important. In this study, the adsorption and sensing of formaldehyde molecule on Pd4 nanocluster decorated carbon nanotube (Pd4-CNT) was investigated by using DFT method. The WB97XD hybrid method was used in DFT calculations. The adsorption energy value was calculated as −8.1 kJ/mol. This low adsorption energy confirms the very short recovery time and the predominance of weak interactions. There was a decrease of approximately 20% in the HOMO-LUMO gap after the interaction. This result shows that the Pd4-CNT can be used as a sensor at room temperature.
{"title":"Formaldehyde Adsorption and Sensing: A Density Functional Theory Study on Pd4 Nanocluster Decorated CNT Structure","authors":"N. Yuksel, A. Kose, Mehmet Ferdi Fellah","doi":"10.3311/ppch.20522","DOIUrl":"https://doi.org/10.3311/ppch.20522","url":null,"abstract":"The sensing of formaldehyde, one of the volatile organic compounds used in chemical processes, is very important. In this study, the adsorption and sensing of formaldehyde molecule on Pd4 nanocluster decorated carbon nanotube (Pd4-CNT) was investigated by using DFT method. The WB97XD hybrid method was used in DFT calculations. The adsorption energy value was calculated as −8.1 kJ/mol. This low adsorption energy confirms the very short recovery time and the predominance of weak interactions. There was a decrease of approximately 20% in the HOMO-LUMO gap after the interaction. This result shows that the Pd4-CNT can be used as a sensor at room temperature.","PeriodicalId":19922,"journal":{"name":"Periodica Polytechnica Chemical Engineering","volume":"101 1","pages":""},"PeriodicalIF":1.3,"publicationDate":"2023-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73785422","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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