D. Chaabane, A. Yakdhane, G. Vatai, A. Koris, Arijit Nath
Olive oil has been received a great importance around the globe because it provides unique functional value. Olive oil prevents the risks of several chronic and acute metabolic disorders because it is enriched with monounsaturated fatty acids, antioxidant phenolic compounds, vitamin E and vitamin K. Unfortunately, oxidative deterioration of fatty acids in olive oil provides short shelf life and reduces biological activities. It is responsible for undesirable organoleptic properties. It may belief that one of the solutions to preserve the quality of olive oil is microencapsulation. In this review, comprehensive information about techniques to prepare olive oil microcapsule is represented. To prepare olive oil microcapsule, emulsification of olive oil with different wall materials (matrixes) has been adopted as a primary step. Subsequently, dehydration of emulsion by spray drying or freeze drying or coacervation process has been adopted to prepare olive oil microcapsule. Moreover, microcapsule of olive oil has been prepared by extrusion technology. Biopolymers, such as proteins and polysaccharides have been used as wall material for encapsulation of olive oil. As stable emulsification is one of important issue to produce microcapsule, several emulsifiers, such as lecithin, tween 20 have been used during emulsion preparation. Different characteristics of the microcapsule of olive oil are summarized because it is influenced by several factors during preparation of microcapsule. In later exercise, several applications of encapsulated olive oil in food, pharmaceutical and cosmetic industries are represented in comprehensive way. It may expect that this review article will receive attention in industries and academic sectors.
{"title":"Microencapsulation of Olive Oil","authors":"D. Chaabane, A. Yakdhane, G. Vatai, A. Koris, Arijit Nath","doi":"10.3311/ppch.19587","DOIUrl":"https://doi.org/10.3311/ppch.19587","url":null,"abstract":"Olive oil has been received a great importance around the globe because it provides unique functional value. Olive oil prevents the risks of several chronic and acute metabolic disorders because it is enriched with monounsaturated fatty acids, antioxidant phenolic compounds, vitamin E and vitamin K. Unfortunately, oxidative deterioration of fatty acids in olive oil provides short shelf life and reduces biological activities. It is responsible for undesirable organoleptic properties. It may belief that one of the solutions to preserve the quality of olive oil is microencapsulation. In this review, comprehensive information about techniques to prepare olive oil microcapsule is represented. To prepare olive oil microcapsule, emulsification of olive oil with different wall materials (matrixes) has been adopted as a primary step. Subsequently, dehydration of emulsion by spray drying or freeze drying or coacervation process has been adopted to prepare olive oil microcapsule. Moreover, microcapsule of olive oil has been prepared by extrusion technology. Biopolymers, such as proteins and polysaccharides have been used as wall material for encapsulation of olive oil. As stable emulsification is one of important issue to produce microcapsule, several emulsifiers, such as lecithin, tween 20 have been used during emulsion preparation. Different characteristics of the microcapsule of olive oil are summarized because it is influenced by several factors during preparation of microcapsule. In later exercise, several applications of encapsulated olive oil in food, pharmaceutical and cosmetic industries are represented in comprehensive way. It may expect that this review article will receive attention in industries and academic sectors.","PeriodicalId":19922,"journal":{"name":"Periodica Polytechnica Chemical Engineering","volume":"23 1","pages":""},"PeriodicalIF":1.3,"publicationDate":"2022-02-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78582190","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 conventional way to characterize the proportion of non-conforming parts in a process is to calculate process capability indices and transform them into a ratio. These widely used indices are able to give digestible information about the ratio of non-conforming parts if some assumptions are fulfilled. A correct estimation method should be based on the output distribution of the process, and the uncertainty of the parameter estimates should be considered, as well. In this article, a special case of the output distribution is examined: a mixture of normal distributions is considered. In practice, this output distribution appears if a multiple stream process is investigated. The novelty of this study is to apply the tolerance interval-based estimation method for the proportion of non-conforming parts in a case study of a multiple stream process and to qualify the limitations of the proposed estimation method. A simulation study is performed to investigate the bias, mean square error, and root mean square error of the estimates from the two estimation methods (process performance index-based and tolerance interval-based) for different sample sizes for each stream (N ). It was found that, if it may be assumed that the speed of the streams is equal in the case of the sample sizes investigated (N = 25, 50, 100 per head), the proposed (tolerance interval-based) method overestimates the proportion of non-conforming parts while the conventional (process performance index-based) method underestimates it. The tolerance-limit based estimation method has asymptotically better properties than the process performance index-based estimation method.
{"title":"Tolerance Limit-based Estimation of the Proportion of Non-conforming Parts in a Multiple Stream Process","authors":"É. Pusztai, S. Kemény","doi":"10.3311/ppch.19338","DOIUrl":"https://doi.org/10.3311/ppch.19338","url":null,"abstract":"The conventional way to characterize the proportion of non-conforming parts in a process is to calculate process capability indices and transform them into a ratio. These widely used indices are able to give digestible information about the ratio of non-conforming parts if some assumptions are fulfilled. A correct estimation method should be based on the output distribution of the process, and the uncertainty of the parameter estimates should be considered, as well. In this article, a special case of the output distribution is examined: a mixture of normal distributions is considered. In practice, this output distribution appears if a multiple stream process is investigated. The novelty of this study is to apply the tolerance interval-based estimation method for the proportion of non-conforming parts in a case study of a multiple stream process and to qualify the limitations of the proposed estimation method. A simulation study is performed to investigate the bias, mean square error, and root mean square error of the estimates from the two estimation methods (process performance index-based and tolerance interval-based) for different sample sizes for each stream (N ). It was found that, if it may be assumed that the speed of the streams is equal in the case of the sample sizes investigated (N = 25, 50, 100 per head), the proposed (tolerance interval-based) method overestimates the proportion of non-conforming parts while the conventional (process performance index-based) method underestimates it. The tolerance-limit based estimation method has asymptotically better properties than the process performance index-based estimation method.","PeriodicalId":19922,"journal":{"name":"Periodica Polytechnica Chemical Engineering","volume":"9 1","pages":""},"PeriodicalIF":1.3,"publicationDate":"2022-02-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73402564","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}
J. Vladić, Nataša Nastić, T. Janković, K. Šavikin, N. Menković, I. Lončarević, S. Vidovic
Multiple medical properties and beneficial influence on health attributed to the aerial parts of Sideritis raeseri Boiss. & Heldr. subsp. raeseri indicated the need for further investigation. S. raeseri extracts were subjected to microencapsulation by the spray drying process in order to disperse and preserve unstable active compounds within a protective matrix. Two inlet air temperatures (120 and 140 ºC) were applied for the encapsulation of S. raeseri extract in a matrix composed of maltodextrin (10, 20, and 40%) or whey protein (40%). The effects of spray drying on physico-chemical properties, contents of total phenols and flavonoids, as well as of individual flavonoid glycosides of the obtained powders were determined. The 40% whey protein treatment increased bulk density (238.46 mg/mL) while it decreased hygroscopicity (14.27%). In addition, the high maltodextrin concentration of the S. raeseri powder resulted in the highest process efficiency (63.46%), the highest water solubility index (86.40%), and the lowest water absorption index (5.71%). Moreover, powders produced without maltodextrin were characterized by greater content of flavonoid glycosides. Overall, the results suggested that S. raeseri powders produced using spray-dried technique under adequate conditions could be considered as a novel functional and pharmaceutical ingredient.
{"title":"Microencapsulation of Sideritis raeseri Boiss. & Heldr. subsp. raeseri Extract Using Spray Drying with Maltodextrin and Whey Protein","authors":"J. Vladić, Nataša Nastić, T. Janković, K. Šavikin, N. Menković, I. Lončarević, S. Vidovic","doi":"10.3311/ppch.19060","DOIUrl":"https://doi.org/10.3311/ppch.19060","url":null,"abstract":"Multiple medical properties and beneficial influence on health attributed to the aerial parts of Sideritis raeseri Boiss. & Heldr. subsp. raeseri indicated the need for further investigation. S. raeseri extracts were subjected to microencapsulation by the spray drying process in order to disperse and preserve unstable active compounds within a protective matrix. Two inlet air temperatures (120 and 140 ºC) were applied for the encapsulation of S. raeseri extract in a matrix composed of maltodextrin (10, 20, and 40%) or whey protein (40%). The effects of spray drying on physico-chemical properties, contents of total phenols and flavonoids, as well as of individual flavonoid glycosides of the obtained powders were determined. The 40% whey protein treatment increased bulk density (238.46 mg/mL) while it decreased hygroscopicity (14.27%). In addition, the high maltodextrin concentration of the S. raeseri powder resulted in the highest process efficiency (63.46%), the highest water solubility index (86.40%), and the lowest water absorption index (5.71%). Moreover, powders produced without maltodextrin were characterized by greater content of flavonoid glycosides. Overall, the results suggested that S. raeseri powders produced using spray-dried technique under adequate conditions could be considered as a novel functional and pharmaceutical ingredient.","PeriodicalId":19922,"journal":{"name":"Periodica Polytechnica Chemical Engineering","volume":"06 1","pages":""},"PeriodicalIF":1.3,"publicationDate":"2022-02-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84766348","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}
Gas chromatography (GC) is an effective tool for the analysis of complex mixtures with a huge number of components. To keep tracking the chemical changes during the processes like plastic waste pyrolysis usually different sample states are profiled, but retention time drifts between the chromatograms make the comparability difficult. The aim of this study is to develop a fast and simple method to eliminate the time drifts between the chromatograms using easily accessible priori information. The proposed method is tested on GC chromatograms obtained by analysis of pyrolysis product (Mg/Y catalyst) of shredded real waste HDPE/PP/LDPE mixture. A modified k-means algorithm was developed to account the retention time drifts between samples (different sample states). The outcome of the retention time alignment is an averaged retention time for each peak from all the chromatograms which makes the comparison and further analysis (such as "fingerprinting") easier or possible.
{"title":"Semi-supervised Clustering Algorithm for Retention Time Alignment of Gas Chromatographic Data","authors":"Omar Péter Hamadi, T. Varga","doi":"10.3311/ppch.18834","DOIUrl":"https://doi.org/10.3311/ppch.18834","url":null,"abstract":"Gas chromatography (GC) is an effective tool for the analysis of complex mixtures with a huge number of components. To keep tracking the chemical changes during the processes like plastic waste pyrolysis usually different sample states are profiled, but retention time drifts between the chromatograms make the comparability difficult. The aim of this study is to develop a fast and simple method to eliminate the time drifts between the chromatograms using easily accessible priori information. The proposed method is tested on GC chromatograms obtained by analysis of pyrolysis product (Mg/Y catalyst) of shredded real waste HDPE/PP/LDPE mixture. A modified k-means algorithm was developed to account the retention time drifts between samples (different sample states). The outcome of the retention time alignment is an averaged retention time for each peak from all the chromatograms which makes the comparison and further analysis (such as \"fingerprinting\") easier or possible.","PeriodicalId":19922,"journal":{"name":"Periodica Polytechnica Chemical Engineering","volume":"94 1","pages":""},"PeriodicalIF":1.3,"publicationDate":"2022-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78107963","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}
Fahimeh Hooriabad Saboor, Samaneh Hadian-Ghazvini, M. Torkashvand
Separation and removal of microplastic pollution from aquatic environments as a global environmental issue is classified as one of the major concerns in both water and wastewater treatment plants. Microplastics as polymeric particles less than 5 mm in at least one dimension are found with different shapes, chemical compositions, and sizes in soil, water, and sediments. Conventional treatment methods for organic separation have shown high removal efficiency for microplastics, while the separation of small microplastic particles, mainly less than 100 µm, in wastewater treatment plants is particularly challenging. This review aims to review the principle and application of different physical and chemical methods for the separation and removal of microplastic particles from aquatic environments, especially in water treatments process, with emphasis on some alternative and emerging separation methods. Advantages and disadvantages of conventional separation techniques such as clarification, sedimentation, floatation, activated sludge, sieving, filtration, and density separation are discussed. The advanced separation methods can be integrated with conventional techniques or utilize as a separate step for separating small microplastic particles. These advanced microplastic separation methods include membrane bioreactor, magnetic separation, micromachines, and degradation-based methods such as electrocatalysis, photocatalysis, biodegradation, and thermal degradation.
{"title":"Microplastics in Aquatic Environments: Recent Advances in Separation Techniques","authors":"Fahimeh Hooriabad Saboor, Samaneh Hadian-Ghazvini, M. Torkashvand","doi":"10.3311/ppch.18930","DOIUrl":"https://doi.org/10.3311/ppch.18930","url":null,"abstract":"Separation and removal of microplastic pollution from aquatic environments as a global environmental issue is classified as one of the major concerns in both water and wastewater treatment plants. Microplastics as polymeric particles less than 5 mm in at least one dimension are found with different shapes, chemical compositions, and sizes in soil, water, and sediments. Conventional treatment methods for organic separation have shown high removal efficiency for microplastics, while the separation of small microplastic particles, mainly less than 100 µm, in wastewater treatment plants is particularly challenging. This review aims to review the principle and application of different physical and chemical methods for the separation and removal of microplastic particles from aquatic environments, especially in water treatments process, with emphasis on some alternative and emerging separation methods. Advantages and disadvantages of conventional separation techniques such as clarification, sedimentation, floatation, activated sludge, sieving, filtration, and density separation are discussed. The advanced separation methods can be integrated with conventional techniques or utilize as a separate step for separating small microplastic particles. These advanced microplastic separation methods include membrane bioreactor, magnetic separation, micromachines, and degradation-based methods such as electrocatalysis, photocatalysis, biodegradation, and thermal degradation.","PeriodicalId":19922,"journal":{"name":"Periodica Polytechnica Chemical Engineering","volume":"29 1","pages":""},"PeriodicalIF":1.3,"publicationDate":"2022-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73939761","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}
This study investigated the effect of reaction parameter, reaction kinetics and mechanism of transesterification of sunflower oil with methanol by using CaO/ZnO heterogeneous catalyst. The influence of reaction time, molar ratio and catalyst amount and reaction temperature on fatty acid methyl esters (FAME) yield was investigated. The catalysts were prepared by incipient wetness impregnation and characterized by using X-ray diffraction (XRD) and Hammett indicator method. The FAME contents were analyzed by gas chromatography using the EN 14103 standard method. The highest FAME yield of 82% was obtained at 9/1 methanol/oil molar ratio, 3 wt.% catalyst amount and 3 hours of reaction time at 65 °C of reaction temperature by using 20% CaO/ZnO catalyst. The reaction could be considered pseudo first order with respect to triglyceride (TG). The reaction model based on Eley-Rideal mechanism was proposed where adsorbed methanol reacted with TG before desorption of glycerin. The results showed that experimental reaction rates exhibited good agreement with calculated reaction rates.
{"title":"Study on Kinetics and Reaction Parameters of Biodiesel Production from Sunflower Oil and Methanol Using Zinc Oxide Supported Calcium Oxide","authors":"O. Ilgen","doi":"10.3311/ppch.19198","DOIUrl":"https://doi.org/10.3311/ppch.19198","url":null,"abstract":"This study investigated the effect of reaction parameter, reaction kinetics and mechanism of transesterification of sunflower oil with methanol by using CaO/ZnO heterogeneous catalyst. The influence of reaction time, molar ratio and catalyst amount and reaction temperature on fatty acid methyl esters (FAME) yield was investigated. The catalysts were prepared by incipient wetness impregnation and characterized by using X-ray diffraction (XRD) and Hammett indicator method. The FAME contents were analyzed by gas chromatography using the EN 14103 standard method. The highest FAME yield of 82% was obtained at 9/1 methanol/oil molar ratio, 3 wt.% catalyst amount and 3 hours of reaction time at 65 °C of reaction temperature by using 20% CaO/ZnO catalyst. The reaction could be considered pseudo first order with respect to triglyceride (TG). The reaction model based on Eley-Rideal mechanism was proposed where adsorbed methanol reacted with TG before desorption of glycerin. The results showed that experimental reaction rates exhibited good agreement with calculated reaction rates.","PeriodicalId":19922,"journal":{"name":"Periodica Polytechnica Chemical Engineering","volume":"48 8","pages":""},"PeriodicalIF":1.3,"publicationDate":"2022-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72583335","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}
B. Nagy, K. Nagy, Balázs Ivanics, D. Fozer, I. Balogh, Á. Németh
The techniques of heterotrophic microalgae cultivation used to be resulting in higher productivity and better yield than autotrophic culturing. Batch cultivation strategy is commonly used with high glucose concentration, but its potential is limited for biomass production at an industrial scale. Usually, the best productivity can obtain at lower glucose concentration. Moreover, other carbon sources can cause inhibition at higher concentrations. Therefore, the fed-batch cultivation strategy is an obvious choice, as it can maintain the optimal amount of carbon source can be maintained throughout the fermentation by automating the feeding. Such self-regulatory automation is provided by the pH-auxostat addition of acetic acid, which was investigated in this study for Chlorella vulgaris fo. tertia. The pH-auxostat fermentation was upscaled, then the feeding profile was modelled and transformed to another fermentation where glucose was used as a carbon source instead of acetic acid. Thus, the preferred carbon sources were compared under the same circumstances. It was found that the tested strain consumes dissolved oxygen very fast on both carbon substrates. It favored the acetic acid at high nitrogen and phosphorus concentrations. The final biomass concentration was 29.2 g/L under pH-auxostat fed-batch strategy with acetic acid and 18.8 g/L with glucose, respectively. The highest lipid content (393 mg/g) was measured from the biomass in the case of acetic acid. The fermentation settings need further optimization, but the results concluded that pH-auxostat acetic acid feeding has a great potential for scale-up of Chlorella fermentation.
{"title":"Effect of Fed-batch Culturing on the Growth and Lipid Production of Chlorella vulgaris fo. tertia Applying pH-auxostat Acetic Acid and Predefined Exponential Glucose Feeding","authors":"B. Nagy, K. Nagy, Balázs Ivanics, D. Fozer, I. Balogh, Á. Németh","doi":"10.3311/ppch.19093","DOIUrl":"https://doi.org/10.3311/ppch.19093","url":null,"abstract":"The techniques of heterotrophic microalgae cultivation used to be resulting in higher productivity and better yield than autotrophic culturing. Batch cultivation strategy is commonly used with high glucose concentration, but its potential is limited for biomass production at an industrial scale. Usually, the best productivity can obtain at lower glucose concentration. Moreover, other carbon sources can cause inhibition at higher concentrations. Therefore, the fed-batch cultivation strategy is an obvious choice, as it can maintain the optimal amount of carbon source can be maintained throughout the fermentation by automating the feeding. Such self-regulatory automation is provided by the pH-auxostat addition of acetic acid, which was investigated in this study for Chlorella vulgaris fo. tertia. The pH-auxostat fermentation was upscaled, then the feeding profile was modelled and transformed to another fermentation where glucose was used as a carbon source instead of acetic acid. Thus, the preferred carbon sources were compared under the same circumstances. It was found that the tested strain consumes dissolved oxygen very fast on both carbon substrates. It favored the acetic acid at high nitrogen and phosphorus concentrations. The final biomass concentration was 29.2 g/L under pH-auxostat fed-batch strategy with acetic acid and 18.8 g/L with glucose, respectively. The highest lipid content (393 mg/g) was measured from the biomass in the case of acetic acid. The fermentation settings need further optimization, but the results concluded that pH-auxostat acetic acid feeding has a great potential for scale-up of Chlorella fermentation.","PeriodicalId":19922,"journal":{"name":"Periodica Polytechnica Chemical Engineering","volume":"20 1","pages":""},"PeriodicalIF":1.3,"publicationDate":"2022-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82143436","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}
L. M. Anaya-Esparza, A. Vargas‐Torres, H. Palma‐Rodríguez, M. P. Castro-Mendoza, E. Yahia, A. Pérez-Larios, E. Montalvo-González
The physicochemical, mechanical, and structural properties of chitosan-based films (CS) alone or CS-films with mixed oxide nanoparticles (TiO2-ZnO-MgO, TZM; CSTZM) at different concentrations (125, 250, and 500 μg mL−1) were investigated. The addition of nano-TZM promoted a color change (from colorless to white) in the film-forming solution, which increased its turbidity and it decreased viscosity. CSTZM were semitransparent (transmittance, T% decreased up to 49%) compared to CS-based films (T% = 95.5). CSTZM (particularly at a concentration of 500 μg mL−1) exhibited an improvement in the moisture content (decreased from 12.6 to 9.67%), water solubility (decreased from 14.94 to 10.22%), degree of swelling (increased from 19.79 to 36.28%), water vapor barrier (decreased from 6.62 x 10−16 to 4.33 x 10−16 g m−1 h−1 Pa−1), thermal stability (the endotherm peak increased from 99.5 to 157.7 °C), and mechanical properties (tensile strength and elongation at break increased from 4.15 to 4.98 kPa and 6.96 to 56.18%, respectively, while the modulus of elasticity decreased from 144 kPa to 4.11 kPa), without toxicity effects on Artemia salina (93.33% survival). X-ray diffraction and Fourier transform infrared studies demonstrated an interaction between CS-based films and nano-TZM. Overall, this film exhibited great potential for diverse industrial applications.
{"title":"Effect of Mixed Oxide-Based TiO2 on the Physicochemical Properties of Chitosan Films","authors":"L. M. Anaya-Esparza, A. Vargas‐Torres, H. Palma‐Rodríguez, M. P. Castro-Mendoza, E. Yahia, A. Pérez-Larios, E. Montalvo-González","doi":"10.3311/ppch.18953","DOIUrl":"https://doi.org/10.3311/ppch.18953","url":null,"abstract":"The physicochemical, mechanical, and structural properties of chitosan-based films (CS) alone or CS-films with mixed oxide nanoparticles (TiO2-ZnO-MgO, TZM; CSTZM) at different concentrations (125, 250, and 500 μg mL−1) were investigated. The addition of nano-TZM promoted a color change (from colorless to white) in the film-forming solution, which increased its turbidity and it decreased viscosity. CSTZM were semitransparent (transmittance, T% decreased up to 49%) compared to CS-based films (T% = 95.5). CSTZM (particularly at a concentration of 500 μg mL−1) exhibited an improvement in the moisture content (decreased from 12.6 to 9.67%), water solubility (decreased from 14.94 to 10.22%), degree of swelling (increased from 19.79 to 36.28%), water vapor barrier (decreased from 6.62 x 10−16 to 4.33 x 10−16 g m−1 h−1 Pa−1), thermal stability (the endotherm peak increased from 99.5 to 157.7 °C), and mechanical properties (tensile strength and elongation at break increased from 4.15 to 4.98 kPa and 6.96 to 56.18%, respectively, while the modulus of elasticity decreased from 144 kPa to 4.11 kPa), without toxicity effects on Artemia salina (93.33% survival). X-ray diffraction and Fourier transform infrared studies demonstrated an interaction between CS-based films and nano-TZM. Overall, this film exhibited great potential for diverse industrial applications.","PeriodicalId":19922,"journal":{"name":"Periodica Polytechnica Chemical Engineering","volume":"110 1","pages":""},"PeriodicalIF":1.3,"publicationDate":"2022-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85344469","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}
Hasan Kasım, A. Aldeen, Adem Onat, İ. Saraç, Barış Engin, M. Yazıcı
This study investigated the crack propagation behavior of the graphene-reinforced synthetic rubber matrix nanocomposite materials. Graphene-filled rubber conductive nanocomposites developed within the scope of this study were obtained in two stages using mechanical mixers. The relationship between crack propagation and electrical resistance change was investigated using single-edge notched specimens in a tensile tester. Digital image correlation (DIC) technique was used to observe the crack resistance function depending on the local strain distribution. The results from the tests were evaluated to define the relationship between the crack length, the amount of conductive filler, and the change in electrical resistance. The sharp edges of the graphene nanoplatelets negatively affected the fracture resistance of the samples. In addition, it was observed that even at low strain values, gaps were formed in the areas close to the crack tip. The three-dimensional transmission network formed by graphene nanoplatelets dispersed in the matrix improved the electrical conductivity properties of the nanocomposites, so the relationship between crack propagation and electrical resistance change was determined.
{"title":"Investigation of the Crack Propagation in the Graphene/Synthetic Rubber Nanocomposite Materials with DIC Technique","authors":"Hasan Kasım, A. Aldeen, Adem Onat, İ. Saraç, Barış Engin, M. Yazıcı","doi":"10.3311/ppch.19079","DOIUrl":"https://doi.org/10.3311/ppch.19079","url":null,"abstract":"This study investigated the crack propagation behavior of the graphene-reinforced synthetic rubber matrix nanocomposite materials. Graphene-filled rubber conductive nanocomposites developed within the scope of this study were obtained in two stages using mechanical mixers. The relationship between crack propagation and electrical resistance change was investigated using single-edge notched specimens in a tensile tester. Digital image correlation (DIC) technique was used to observe the crack resistance function depending on the local strain distribution. The results from the tests were evaluated to define the relationship between the crack length, the amount of conductive filler, and the change in electrical resistance. The sharp edges of the graphene nanoplatelets negatively affected the fracture resistance of the samples. In addition, it was observed that even at low strain values, gaps were formed in the areas close to the crack tip. The three-dimensional transmission network formed by graphene nanoplatelets dispersed in the matrix improved the electrical conductivity properties of the nanocomposites, so the relationship between crack propagation and electrical resistance change was determined.","PeriodicalId":19922,"journal":{"name":"Periodica Polytechnica Chemical Engineering","volume":"28 1","pages":""},"PeriodicalIF":1.3,"publicationDate":"2022-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74078631","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}
Thuy Tien Nguyen Thanh, K. Decsov, K. Bocz, G. Marosi, B. Szolnoki
As polypropylene (PP) has no charring ability on its own due to the lack of hydroxyl functional groups, the flame retardant system needs the addition of carbonizing agent in a relatively great amount. Ammonium-polyphosphate (APP), a conventional flame retardant additive was modified by microencapsulation with a sorbitol-based bioepoxy resin shell to create an intumescent flame retardant system with enhanced charring ability for PP. The flame retardant efficiency of the microencapsulated additive, which contains all the components needed in an effective intumescent flame retardant system, was evaluated in PP matrix at different loadings.When compared to the physical mixture of the component, the microencapsuated form of APP (MCAPP) was found to have improved flame retardant efficiency in PP. The LOI values of the MCAPP containing PP samples increased by 8–11 V/V% besides achieved V-0 classification according to the UL94 test. During cone calorimeter tests, the burning intensity was reduced (peak of heat release rate decreased by 20–35% and shifted in time), increased amount of charred residue was obtained, and based on the calculated Flame Retardancy Index (FRI) “Excellent” fire performance was achieved when MCAPP was used. The improved flame retardant performance is attributed to the effective interaction between the APP core and the readily available carbonizing shell, which promoted the formation of increased amount of char accompanied with improved heat protecting and barrier efficiency.
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