Abstract This paper presents the results of an analysis of heat transfer in a cross-flow mini heat exchanger (CFMHE). The purpose of the paper was to analyze the results of the experimental measurements presented in the previous work in order to determine dimensionless correlations that allow for the calculation of heat transfer coefficients for the CFMHE. Analyzed CFMHE consisted of a brass cylindrical core, in which 2 mm circular holes were drilled. A method based on an optimization procedure was used to determine the correlations describing the heat transfer coefficients, allowing the correlations to be determined without the need of measuring the mini channel wall temperature. Overall heat transfer coefficients calculated using the proposed correlations typically did not deviate by more than ±10% from the corresponding experimental results, which was a significant improvement in the quality of the fit compared to the results presented in previous work.
{"title":"Heat transfer in compact cross-flow mini heat exchanger","authors":"Mateusz Prończuk, Aleksander Pabiś","doi":"10.2478/pjct-2023-0028","DOIUrl":"https://doi.org/10.2478/pjct-2023-0028","url":null,"abstract":"Abstract This paper presents the results of an analysis of heat transfer in a cross-flow mini heat exchanger (CFMHE). The purpose of the paper was to analyze the results of the experimental measurements presented in the previous work in order to determine dimensionless correlations that allow for the calculation of heat transfer coefficients for the CFMHE. Analyzed CFMHE consisted of a brass cylindrical core, in which 2 mm circular holes were drilled. A method based on an optimization procedure was used to determine the correlations describing the heat transfer coefficients, allowing the correlations to be determined without the need of measuring the mini channel wall temperature. Overall heat transfer coefficients calculated using the proposed correlations typically did not deviate by more than ±10% from the corresponding experimental results, which was a significant improvement in the quality of the fit compared to the results presented in previous work.","PeriodicalId":20324,"journal":{"name":"Polish Journal of Chemical Technology","volume":"78 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135688208","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}
Muhammad Ibrahim, Moazama Riaz, Akbar Ali, Musarat Shaheen, Shafiq ur Rahman, Riffat Aziz, Abdulhakeem S. Alamri, Majid Alhomrani, Anas S Dablool, Saad Alghamdi, Manal Y. Sameeh, Manal A Tashkandi
Abstract The study was aimed to characterize the antioxidant and anti-microbial activities of Cynodon dactylon with special reference on its precise biochemical analysis. Physiological analysis that total carotenoids content (0.3884 ± 0.0172 mg/g), total chlorophyll content (6.1460 ± 0.2915 mg/g), total phenolic contents (13.4703 ± 0.1494 mg/g), chlorophyll a (3.7708 ± 0.1528 mg/g, catalase (CAT) contents (40.2844 ± 0.1515 units/mg), total anthocyanin contents (5.0166 ± 0.2966 g –1 FW) total soluble proteins (2.9916 ± 0.1734 mg/g) and total flavonoids content (TFC) (4.7863 ± 0.0442 μg/g) was found higher in the leaves of the Cynodon dactylon whereas, chlorophyll b (2.4881 ± 0.1326 mg/g) was found higher in the stem of Cynodon dactylon , while, peroxidase (POD) contents (81.8763 ± 4.6609 units/mg) and superoxidase dismutase (SOD) activity (80.4346 ± 5.9367 units/mg) was investigated higher in roots of Cynodon dactylon . The anti-microbial activity of Cynodon dactylon extracts was performed using a good diffusion technique against two microbial strains. Among all the plant extracts, the methanolic extracts showed a maximum inhibition zone (26.87 mm) against anti-bacterial strain Escherichia coli whereas n-hexane extract showed a maximum inhibition zone (17.88 mm) against anti-fungal strain Candida albicans. This study reported the antimicrobial activity of Cynodon dactylon against some common pathogens such as Staphylococcus aureus, Escherichia coli, and Candida albicans, which are highly associated with nosocomial infection. From the given results it is concluded that Cynodon dactylon could be exploited in pharmacology due to its antioxidant and anti-microbial properties.
{"title":"Evaluating the Total Phenolic, Protein Contents, Antioxidant and Pharmacological Effects of <i>Cynodon dactylon</i> Extracts Against <i>Escherichia coli</i> and <i>Staphylococcus aureus</i>","authors":"Muhammad Ibrahim, Moazama Riaz, Akbar Ali, Musarat Shaheen, Shafiq ur Rahman, Riffat Aziz, Abdulhakeem S. Alamri, Majid Alhomrani, Anas S Dablool, Saad Alghamdi, Manal Y. Sameeh, Manal A Tashkandi","doi":"10.2478/pjct-2023-0031","DOIUrl":"https://doi.org/10.2478/pjct-2023-0031","url":null,"abstract":"Abstract The study was aimed to characterize the antioxidant and anti-microbial activities of Cynodon dactylon with special reference on its precise biochemical analysis. Physiological analysis that total carotenoids content (0.3884 ± 0.0172 mg/g), total chlorophyll content (6.1460 ± 0.2915 mg/g), total phenolic contents (13.4703 ± 0.1494 mg/g), chlorophyll a (3.7708 ± 0.1528 mg/g, catalase (CAT) contents (40.2844 ± 0.1515 units/mg), total anthocyanin contents (5.0166 ± 0.2966 g –1 FW) total soluble proteins (2.9916 ± 0.1734 mg/g) and total flavonoids content (TFC) (4.7863 ± 0.0442 μg/g) was found higher in the leaves of the Cynodon dactylon whereas, chlorophyll b (2.4881 ± 0.1326 mg/g) was found higher in the stem of Cynodon dactylon , while, peroxidase (POD) contents (81.8763 ± 4.6609 units/mg) and superoxidase dismutase (SOD) activity (80.4346 ± 5.9367 units/mg) was investigated higher in roots of Cynodon dactylon . The anti-microbial activity of Cynodon dactylon extracts was performed using a good diffusion technique against two microbial strains. Among all the plant extracts, the methanolic extracts showed a maximum inhibition zone (26.87 mm) against anti-bacterial strain Escherichia coli whereas n-hexane extract showed a maximum inhibition zone (17.88 mm) against anti-fungal strain Candida albicans. This study reported the antimicrobial activity of Cynodon dactylon against some common pathogens such as Staphylococcus aureus, Escherichia coli, and Candida albicans, which are highly associated with nosocomial infection. From the given results it is concluded that Cynodon dactylon could be exploited in pharmacology due to its antioxidant and anti-microbial properties.","PeriodicalId":20324,"journal":{"name":"Polish Journal of Chemical Technology","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135688067","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}
Abstract The synthesis of multifunctional plasticizer using rubber seed oil can increase its added value and expand the application field of plasticized products. Recent studies on bio-based plasticizers focus on bio-based raw materials but products lack functionality. In this study, flame retardant phosphate and chlorine were introduced into the chemical structure of rubber seed oil to synthesis a nitrogen and phosphorus synergistic flame retardant plasticizer based on rubber seed oil(NPFP) and apply it to plasticize polyvinyl chloride (PVC). Thermal stability, limiting oxygen index, plasticizing property, solvent extraction resistance, and microstructure of plasticized PVC materials were characterized. The results showed that NPFP with excellent solvent extraction resistance can significantly enhance the limiting oxygen index and thermal stability of plasticized PVC materials, and can partially replace dioctyl phthalate(DOP) as multifunctional auxiliary plasticizer.
{"title":"Synthesis and properties of chlorine and phosphorus containing rubber seed oil as a second plasticizer for flame retardant polyvinyl chloride materials","authors":"Huabei Li, Xiaolin Wang, Xinding Yao, Hongying Chu","doi":"10.2478/pjct-2023-0015","DOIUrl":"https://doi.org/10.2478/pjct-2023-0015","url":null,"abstract":"Abstract The synthesis of multifunctional plasticizer using rubber seed oil can increase its added value and expand the application field of plasticized products. Recent studies on bio-based plasticizers focus on bio-based raw materials but products lack functionality. In this study, flame retardant phosphate and chlorine were introduced into the chemical structure of rubber seed oil to synthesis a nitrogen and phosphorus synergistic flame retardant plasticizer based on rubber seed oil(NPFP) and apply it to plasticize polyvinyl chloride (PVC). Thermal stability, limiting oxygen index, plasticizing property, solvent extraction resistance, and microstructure of plasticized PVC materials were characterized. The results showed that NPFP with excellent solvent extraction resistance can significantly enhance the limiting oxygen index and thermal stability of plasticized PVC materials, and can partially replace dioctyl phthalate(DOP) as multifunctional auxiliary plasticizer.","PeriodicalId":20324,"journal":{"name":"Polish Journal of Chemical Technology","volume":"25 1","pages":"36 - 42"},"PeriodicalIF":1.0,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44038226","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}
Cássio R.A. Silva, Victor C. Panuci, M. R. Coutinho, W.A.dos S. Conceição, C. M. Andrade
Abstract The union of different devices in order to obtain a specific response for a process is commonly called a control system. For a control system, it is necessary to have one or more controllers. Among the most used in the industrial sector are the PID and PI controllers. Next to these controllers is the control software. Scilab is a good example of control software. It is characterized as free code software, with no cost for its acquisition, in addition to having a large computational power and integrated tools, such as Xcos, intended for modeling and simulation. For the union with Scilab, there is Arduino. Such a mixture can be used, for example, to control liquid levels in tanks. In this context, the present work aims to study the tank-level control system based on PID and PI controllers through the union between Scilab and Arduino. Phenomenological models were developed based on closed-loop control (feedback control system) of the process with two tanks not coupled with recycle. Furthermore, for comparison purposes, two approaches were used for each process: one considering the saturation of the manipulated variable and the other without the presence of such saturation. At first, there was a need to implement an anti-windup system. For tuning the controller parameters, the ISE method was used, executed through a programming code developed in Scilab. The parameters found for the two systems were tested on a made-up experimental bench. Therefore, using the block diagrams and the method here called “ISE method”, satisfactory values were obtained for the control parameters. These were ratified in the tests carried out in the experimental module. Level control was achieved with greater prominence for the PI controller since there is one less parameter to be tuned and processed by the system. This controller provided results close to the PID controller for cycles up to 50%. In general, the PI controller showed maximum response deviations smaller than the PID, such as deviations of 1.55 cm and 2.40 cm, respectively, for the case with 75% recycle. It was also clear the influence of the saturation of the manipulated variable on the system response, but not on the tuning of the controller parameters.
{"title":"Analysis of the effects of recycling on process control","authors":"Cássio R.A. Silva, Victor C. Panuci, M. R. Coutinho, W.A.dos S. Conceição, C. M. Andrade","doi":"10.2478/pjct-2023-0016","DOIUrl":"https://doi.org/10.2478/pjct-2023-0016","url":null,"abstract":"Abstract The union of different devices in order to obtain a specific response for a process is commonly called a control system. For a control system, it is necessary to have one or more controllers. Among the most used in the industrial sector are the PID and PI controllers. Next to these controllers is the control software. Scilab is a good example of control software. It is characterized as free code software, with no cost for its acquisition, in addition to having a large computational power and integrated tools, such as Xcos, intended for modeling and simulation. For the union with Scilab, there is Arduino. Such a mixture can be used, for example, to control liquid levels in tanks. In this context, the present work aims to study the tank-level control system based on PID and PI controllers through the union between Scilab and Arduino. Phenomenological models were developed based on closed-loop control (feedback control system) of the process with two tanks not coupled with recycle. Furthermore, for comparison purposes, two approaches were used for each process: one considering the saturation of the manipulated variable and the other without the presence of such saturation. At first, there was a need to implement an anti-windup system. For tuning the controller parameters, the ISE method was used, executed through a programming code developed in Scilab. The parameters found for the two systems were tested on a made-up experimental bench. Therefore, using the block diagrams and the method here called “ISE method”, satisfactory values were obtained for the control parameters. These were ratified in the tests carried out in the experimental module. Level control was achieved with greater prominence for the PI controller since there is one less parameter to be tuned and processed by the system. This controller provided results close to the PID controller for cycles up to 50%. In general, the PI controller showed maximum response deviations smaller than the PID, such as deviations of 1.55 cm and 2.40 cm, respectively, for the case with 75% recycle. It was also clear the influence of the saturation of the manipulated variable on the system response, but not on the tuning of the controller parameters.","PeriodicalId":20324,"journal":{"name":"Polish Journal of Chemical Technology","volume":"25 1","pages":"43 - 55"},"PeriodicalIF":1.0,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41757133","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}
Abstract The goal of this study was the immobilization of different lipases as protein-coated microcrystals on K2SO4 and their uses in the synthesis of isoamyl acetate in n-hexane medium. The optimum conditions, such as lipase variety, temperature, the initial molar ratio of vinyl acetate/isoamyl alcohol, immobilized lipase amount, and reaction time were determined. The highest conversion was obtained when protein-coated microcrystals of Thermomyces lanuginosus lipase (TLL-PCMCs) was used for the synthesis of isoamyl acetate. The optimum temperature, the initial molar ratio of vinyl acetate/isoamyl alcohol, immobilized lipase amount, and reaction time were determined to be 50 °C, 3.0, 30 mg, and 360 min, respectively. Under the optimized conditions, isoamyl acetate yield was obtained as 95%. TLL-PCMCs retained 90% of their initial activity after five repeat use in the isoamyl acetate synthesis. TLL-PCMCs may be used in the preparation of industrially important aroma compounds due its ease of preparation and efficiency.
{"title":"Synthesis of isoamyl acetate using protein-coated microcrystals of different lipases","authors":"M. Türk","doi":"10.2478/pjct-2023-0012","DOIUrl":"https://doi.org/10.2478/pjct-2023-0012","url":null,"abstract":"Abstract The goal of this study was the immobilization of different lipases as protein-coated microcrystals on K2SO4 and their uses in the synthesis of isoamyl acetate in n-hexane medium. The optimum conditions, such as lipase variety, temperature, the initial molar ratio of vinyl acetate/isoamyl alcohol, immobilized lipase amount, and reaction time were determined. The highest conversion was obtained when protein-coated microcrystals of Thermomyces lanuginosus lipase (TLL-PCMCs) was used for the synthesis of isoamyl acetate. The optimum temperature, the initial molar ratio of vinyl acetate/isoamyl alcohol, immobilized lipase amount, and reaction time were determined to be 50 °C, 3.0, 30 mg, and 360 min, respectively. Under the optimized conditions, isoamyl acetate yield was obtained as 95%. TLL-PCMCs retained 90% of their initial activity after five repeat use in the isoamyl acetate synthesis. TLL-PCMCs may be used in the preparation of industrially important aroma compounds due its ease of preparation and efficiency.","PeriodicalId":20324,"journal":{"name":"Polish Journal of Chemical Technology","volume":"25 1","pages":"15 - 20"},"PeriodicalIF":1.0,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43481972","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}
X. Le, Tuong-An Tran-Thi, Kieu-Trang Phuong, Minh-Tam Nguyen-Kim, T. Dao
Abstract Sapindus saponins are potential biosurfactants that can widely be used to replace many chemical cleaning products. This study aimed to investigate the water extraction of saponins from the pericarps of Sapindus mukorossi and enhance the sensory properties of the extract by yeast fermentation. Extraction conditions including temperature, solid-to-liquid ratio, extraction time, and number of extraction times were studied. A yield of 21.4% was obtained by 2 h of extraction at 80 °C with a solid-to-liquid of 1/6 (w/v) and two times. Fermentation was used to purify the Sapindus extract, inoculum amount and fermentation time were optimized. The fermentation by S. cerevisiae (2%) within 4 days significantly improved the color and smell of aqueous extract, turbidity decreased by 75.6%, total sugar content decreased by nearly 50% and saponins content slightly decreased. These results could contribute to the development of industrial–scale production of Sapindus saponins.
{"title":"Improvement in extraction and sensory properties of soapnut extract by fermentation","authors":"X. Le, Tuong-An Tran-Thi, Kieu-Trang Phuong, Minh-Tam Nguyen-Kim, T. Dao","doi":"10.2478/pjct-2023-0010","DOIUrl":"https://doi.org/10.2478/pjct-2023-0010","url":null,"abstract":"Abstract Sapindus saponins are potential biosurfactants that can widely be used to replace many chemical cleaning products. This study aimed to investigate the water extraction of saponins from the pericarps of Sapindus mukorossi and enhance the sensory properties of the extract by yeast fermentation. Extraction conditions including temperature, solid-to-liquid ratio, extraction time, and number of extraction times were studied. A yield of 21.4% was obtained by 2 h of extraction at 80 °C with a solid-to-liquid of 1/6 (w/v) and two times. Fermentation was used to purify the Sapindus extract, inoculum amount and fermentation time were optimized. The fermentation by S. cerevisiae (2%) within 4 days significantly improved the color and smell of aqueous extract, turbidity decreased by 75.6%, total sugar content decreased by nearly 50% and saponins content slightly decreased. These results could contribute to the development of industrial–scale production of Sapindus saponins.","PeriodicalId":20324,"journal":{"name":"Polish Journal of Chemical Technology","volume":" ","pages":"1 - 7"},"PeriodicalIF":1.0,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43552587","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}
Abstract The use of a liquid level sensor made it possible to measure changes in gas hold-up over time in a stirred tank during unsteady mixing. These results were subjected to Fourier time series analysis and a model of gas hold-up changes in time was proposed. It allowed one to determine the model value of gas hold-up, which can be useful for characterizing gas hold-up during unsteady mixing and as a comparison to gas hold-up during steady mixing. The characteristic frequency was also determined, which corresponds to about twice the oscillation frequency. Model gas hold-up values for coalescing and non-coalescing systems were compared. Moreover, the change of the gas hold-up at constant maximum stirrer rotation frequency and variable gas flow rate for different oscillation frequencies was investigated.
{"title":"Gas hold-up analysis in an unsteady stirred vessel by means of infinite series","authors":"Sebastian Frankiewicz, S. Woziwodzki","doi":"10.2478/pjct-2023-0014","DOIUrl":"https://doi.org/10.2478/pjct-2023-0014","url":null,"abstract":"Abstract The use of a liquid level sensor made it possible to measure changes in gas hold-up over time in a stirred tank during unsteady mixing. These results were subjected to Fourier time series analysis and a model of gas hold-up changes in time was proposed. It allowed one to determine the model value of gas hold-up, which can be useful for characterizing gas hold-up during unsteady mixing and as a comparison to gas hold-up during steady mixing. The characteristic frequency was also determined, which corresponds to about twice the oscillation frequency. Model gas hold-up values for coalescing and non-coalescing systems were compared. Moreover, the change of the gas hold-up at constant maximum stirrer rotation frequency and variable gas flow rate for different oscillation frequencies was investigated.","PeriodicalId":20324,"journal":{"name":"Polish Journal of Chemical Technology","volume":"25 1","pages":"30 - 35"},"PeriodicalIF":1.0,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46818935","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}
K. Wenelska, T. Kędzierski, K. Maślana, K. Sielicki, A. Dymerska, Joanna Janusz, Grzegorz Marianczyk, A. Gorgon-Kuza, Wojciech Bogdan, E. Mijowska
Abstract The dominance of plastics in the packaging market is due to their low weight and thickness, which save transportation costs. However, their non-biodegradability poses a significant threat to the environment. Paper, on the other hand, is considered as a safer alternative due to its natural composition and biodegradability. The porous structure of paper limits its application in packaging, and its poor water resistance further restricts its use in humid environments. Therefore, lamination is a method useful tool to improve the barrier properties of paper. Additionally, the researchers are focusing on developing biodegradable and water-based coatings with anti-fat properties as a green alternative to plastic packaging. The impact of a new grease-resistant coating composed of starch, gelatin and sodium alginate on the mechanical properties of paper was investigated through tensile, tearing, and bursting strength tests. The results showed significant improvements in the mechanical properties of the coated paper sheets. Furthermore, the biodegradability test indicated that the paper samples coated with the new composition showed a 50% weight loss after one week of incubation in the soil, and after three weeks, they exhibited 100% weight loss, demonstrating their outstanding biodegradability.
{"title":"Biopolymers based paper coating with promoted grease resistivity, bio-degradable and mechanical properties","authors":"K. Wenelska, T. Kędzierski, K. Maślana, K. Sielicki, A. Dymerska, Joanna Janusz, Grzegorz Marianczyk, A. Gorgon-Kuza, Wojciech Bogdan, E. Mijowska","doi":"10.2478/pjct-2023-0018","DOIUrl":"https://doi.org/10.2478/pjct-2023-0018","url":null,"abstract":"Abstract The dominance of plastics in the packaging market is due to their low weight and thickness, which save transportation costs. However, their non-biodegradability poses a significant threat to the environment. Paper, on the other hand, is considered as a safer alternative due to its natural composition and biodegradability. The porous structure of paper limits its application in packaging, and its poor water resistance further restricts its use in humid environments. Therefore, lamination is a method useful tool to improve the barrier properties of paper. Additionally, the researchers are focusing on developing biodegradable and water-based coatings with anti-fat properties as a green alternative to plastic packaging. The impact of a new grease-resistant coating composed of starch, gelatin and sodium alginate on the mechanical properties of paper was investigated through tensile, tearing, and bursting strength tests. The results showed significant improvements in the mechanical properties of the coated paper sheets. Furthermore, the biodegradability test indicated that the paper samples coated with the new composition showed a 50% weight loss after one week of incubation in the soil, and after three weeks, they exhibited 100% weight loss, demonstrating their outstanding biodegradability.","PeriodicalId":20324,"journal":{"name":"Polish Journal of Chemical Technology","volume":"25 1","pages":"66 - 71"},"PeriodicalIF":1.0,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47715774","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}
Shaukat Ali, N. M. Ranjha, B. Ahmad, Ayaz Ali Khan, Fakhr Ul Hassan, T. Aziz, M. Alharbi, A. Alshammari, A. Alasmari, M. Alharbi
Abstract The present study aimed to prepare hydrogel based on polyvinyl alcohol (PVA) and gelatin (Ge) and characterization of PVA/Ge hydrogel for their potential use as a sustained drug delivery system. Polyvinyl Alcohol (PVA) and-Gelatin (Ge) were cross-linked using glutaraldehyde (GA) as a crosslinking agent and hydrochloric acid (HCl) as a catalyst. Different feed polymer ratio and crosslinking agent concentration were used to prepare a series of PVA/Ge hydrogels. The obtained PVA/Ge hydrogels were investigated for dynamic and equilibrium swelling studies. The effect of polymers ratio, degree of crosslinking and pH of the medium on swelling of PVA/Ge hydrogels was investigated. Furthermore, the values of diffusion coefficient (D), volume fraction, polymer-solvent interaction parameter, molecular weight between crosslink and crosslink density were calculated. For swelling studies, 0.05M USP phosphate buffer solutions of different pH (1.2, 5.5, 6.5 and 7.5) were used. For the drug release study, ciprofloxacin HCl was loaded into selected samples as a model drug. The release of drug from these samples was performed for 12 hours in USP phosphate buffers of pH 1.2, 5.5 and 7.5. The release data from these samples were fitted into various kinetic models like zero order, first order, Higuchi and Peppas models to investigate the release mechanism. It was found that by varying the composition of PVA/Ge hydrogel and GA concentration, a significant difference was observed in drug release kinetics. FTIR spectroscopy and X-ray diffraction were used for the characterization of hydrogels. PVA/Ge hydrogel showed sustained release of the model drug at various pH values suggesting its potential use as a sustained drug delivery system.
{"title":"Sustained Release of Drug Facilitated Through Chemically Crosslinked Polyvinyl Alcohol-Gelatin (PVA-GE) Hydrogels. A sustainable biomedical approach","authors":"Shaukat Ali, N. M. Ranjha, B. Ahmad, Ayaz Ali Khan, Fakhr Ul Hassan, T. Aziz, M. Alharbi, A. Alshammari, A. Alasmari, M. Alharbi","doi":"10.2478/pjct-2023-0017","DOIUrl":"https://doi.org/10.2478/pjct-2023-0017","url":null,"abstract":"Abstract The present study aimed to prepare hydrogel based on polyvinyl alcohol (PVA) and gelatin (Ge) and characterization of PVA/Ge hydrogel for their potential use as a sustained drug delivery system. Polyvinyl Alcohol (PVA) and-Gelatin (Ge) were cross-linked using glutaraldehyde (GA) as a crosslinking agent and hydrochloric acid (HCl) as a catalyst. Different feed polymer ratio and crosslinking agent concentration were used to prepare a series of PVA/Ge hydrogels. The obtained PVA/Ge hydrogels were investigated for dynamic and equilibrium swelling studies. The effect of polymers ratio, degree of crosslinking and pH of the medium on swelling of PVA/Ge hydrogels was investigated. Furthermore, the values of diffusion coefficient (D), volume fraction, polymer-solvent interaction parameter, molecular weight between crosslink and crosslink density were calculated. For swelling studies, 0.05M USP phosphate buffer solutions of different pH (1.2, 5.5, 6.5 and 7.5) were used. For the drug release study, ciprofloxacin HCl was loaded into selected samples as a model drug. The release of drug from these samples was performed for 12 hours in USP phosphate buffers of pH 1.2, 5.5 and 7.5. The release data from these samples were fitted into various kinetic models like zero order, first order, Higuchi and Peppas models to investigate the release mechanism. It was found that by varying the composition of PVA/Ge hydrogel and GA concentration, a significant difference was observed in drug release kinetics. FTIR spectroscopy and X-ray diffraction were used for the characterization of hydrogels. PVA/Ge hydrogel showed sustained release of the model drug at various pH values suggesting its potential use as a sustained drug delivery system.","PeriodicalId":20324,"journal":{"name":"Polish Journal of Chemical Technology","volume":"25 1","pages":"56 - 65"},"PeriodicalIF":1.0,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48122779","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}
Feng-jie Zhang, Yonglu Dong, Shudong Lin, Xuefeng Gui, Jiwen Hu
Abstract The epoxidation process of soybean oil (SBO) and peracid produced by 50 wt% hydrogen peroxide (H2O2) and formic acid (FA) was studied with sulfuric acid (H2SO4) as a catalyst. Three reaction parameters, including reaction temperature, FA-to-SBO ratio, and H2O2-to-SBO ratio, were investigated, along with the combined effect on oxirane value (OV). Based on response surface methodology (RSM), the Box-Behnken design (BBD) was used to optimize the process parameters. According to the results, the calculated OV (7.34%) and the experimental OV (7.31%) were signifi cantly in agreement. The product was confi rmed as epoxidized soybean oil (ESO) by IR and NMR characterization methods. These results demonstrated the reliability of RSM to optimize the SBO reaction to produce ESO with high oxygen content.
{"title":"Optimization of production process of epoxidized soybean oil with high oxygen content through response surface methodology","authors":"Feng-jie Zhang, Yonglu Dong, Shudong Lin, Xuefeng Gui, Jiwen Hu","doi":"10.2478/pjct-2023-0013","DOIUrl":"https://doi.org/10.2478/pjct-2023-0013","url":null,"abstract":"Abstract The epoxidation process of soybean oil (SBO) and peracid produced by 50 wt% hydrogen peroxide (H2O2) and formic acid (FA) was studied with sulfuric acid (H2SO4) as a catalyst. Three reaction parameters, including reaction temperature, FA-to-SBO ratio, and H2O2-to-SBO ratio, were investigated, along with the combined effect on oxirane value (OV). Based on response surface methodology (RSM), the Box-Behnken design (BBD) was used to optimize the process parameters. According to the results, the calculated OV (7.34%) and the experimental OV (7.31%) were signifi cantly in agreement. The product was confi rmed as epoxidized soybean oil (ESO) by IR and NMR characterization methods. These results demonstrated the reliability of RSM to optimize the SBO reaction to produce ESO with high oxygen content.","PeriodicalId":20324,"journal":{"name":"Polish Journal of Chemical Technology","volume":"25 1","pages":"21 - 29"},"PeriodicalIF":1.0,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47750008","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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