Packaging Treatments Research Articles

A Review of Chitosan-Based Materials for Biomedical, Food, and Water Treatment Applications

Chitosan, a natural biopolymer with excellent biocompatibility, biodegradability, and modifiable structure, has broad applications in regenerative medicine, tissue engineering, food packaging, and environmental technology. Its abundance, solubility in acidic solutions, and capacity for chemical modification make it highly adaptable for creating specialized derivatives with enhanced properties. Recent advances have demonstrated chitosan’s efficacy in composite systems for tissue regeneration, drug delivery, and antimicrobial applications. This review examines chitosan’s unique properties, with a focus on its antibacterial activity as influenced by factors like pH, concentration, molecular weight, and deacetylation degree. Additionally, chitosan’s potential as a sustainable, non-toxic material for eco-friendly packaging and water treatment is explored, highlighting the growing interest in chitosan composites with other polymers and metallic nanoparticles for enhanced biomedical and environmental applications.

Effect of chlorine dioxide (ClO2) combined with different oxygen permeability package treatments on postharvest antioxidant activity and storage life of ‘Liaofeng’ grapes

To enhance the storage quality of ‘Liaofeng’ grapes, this research employed chlorine dioxide in collaboration with different package of preservative bags to explore its preservative effect on ‘Liaofeng’ grapes. After fumigating the grapes with 300 mg L−1 ClO2 solution, the control group was packaged in unpacked and PE bags, while the treatment group was packaged in three kinds of bags with different oxygen permeability, and stored in 4 °C and relative humidity controlled at 90%–95% for 90 days. The results showed that ClO2-GB package treatment significantly delayed the decline of grape hardness (P < 0.05), and decreased the weight loss, threshing, decay and peduncle browning index after storage for 90 days. ClO2-GB package treatment not only diminishes the levels of soluble solids content, titrable acidity, ascorbic acid and glutathione but also effectively suppresses the respiration rate in fruits. The contents of total phenols, flavonoids, anthocyanins and reduced glutathione after ClO2-GB treatment were significantly higher than those in unpackaged group (P < 0.05), and curbed the increase in relative electrical conductivity and malondialdehyde concentration. In comparison to ClO2-YTB and ClO2-YB treatments, ClO2-GB treatment demonstrated superior efficacy in modulating the antioxidant metabolism of grapes. It notably elevated the enzymatic activities of catalase, superoxide dismutase, ascorbate peroxidase, and glutathione reductase, while inhibiting the activities of peroxidase and polyphenol oxidase. The quality assessment of ‘Liaofeng’ grapes after 90 d storage period, conducted through principal component analysis (PCA), yielded the following ranking: ClO2-GB > ClO2-YB > ClO2-YTB > ClO2-PE > ClO2. This suggests that 300 mg L−1 ClO2 fumigation combined with different package treatments was more beneficial to the storage of ‘Liaofeng’ grape. ClO2-GB package treatment emerged as the most advantageous.

Vacuum Packaging Can Protect Ground Beef Color and Oxidation during Cold Storage.

Storing ground beef at frozen temperatures prior to refrigerated display when using thermoforming vacuum packaging is not a common manufacturing practice. However, limited data on thermoforming packaging film and its interaction with meat quality suggests that more information is needed. The current study aimed to identify the influences of thermoforming packaging on the surface color and lipid oxidation of ground beef. Ground beef was portioned into 454 g bricks and packaged into one of three thermoforming films: T1 (150 µ polyethylene/EVOH/polyethylene coextrusion), T2 (175 µ polyethylene /EVOH/polyethylene coextrusion), and T3 (200 µ polyethylene/EVOH/polyethylene coextrusion), stored for 21 days at -20.83 °C (±1.50 °C), and displayed for 42 days at 3.0 °C ± 1.5 °C. There were no statistical differences for the packaging treatment of lipid oxidation (p = 0.0744), but oxidation increased throughout storage day (p < 0.0001). The main effects of treatment and day resulted in altered (p < 0.05) surface lightness (L*), redness (a*), yellowness, hue angle (°), red-to-brown (RTB), and relative myoglobin for met-myoglobin (MET), deoxymyoglobin (DMB), and oxymyoglobin (OMB). Surprisingly, there was an interaction between treatment and day for the calculated relative values of chroma (p = 0.0321), Delta E (p = 0.0155), and the ratio of a*:b* (p < 0.0001). These results indicate that thermoforming vacuum packaging can reduce the rate of deterioration that occurs to ground beef color and the rate of oxidation.

The effect of plastic packaging type on the quality of natural flavor products from white shrimp (Penaeus indicus) by-product

Abstract Flavor shrimp paste product is a type of shrimp by-product flavoring as a way to increase the economic value of shrimp by-products. The food industry requires development in determining the type of product packaging. This study aims to determine the effect of different types of plastic packaging on product quality flavor shrimp paste. The treatment used is the type of product plastic packaging flavor High-Density Polyethylene (P1), Polyethylene Terephthalate (P2), and Polypropylene (P3) shrimp paste which were stored for 6 days. The main parameters in this study consisted of the total plate count (TPC) test and the hedonic test (appearance, taste, aroma, and texture), while the supporting parameters in this study were the proximate test (protein content, fat content, and water content). Based on the research showed that flavor shrimp paste product with different types of packaging gave a significant difference (p&lt;0.05) to the TPC test, hedonic test, and proximate test flavor shrimp products. Treatment of HDPE plastic packaging is the best type of plastic packaging for quality flavor shrimp paste product.

The Effect of Putrescine and Modified Atmosphere Packaging (MAP) Treatments on Fruit Quality Characteristics of Strawberry (Kabarla cultivar) During Cold Storage

Strawberry is a fruit species that must be harvested at full ripening and at the same time has an extremely short shelf life and deteriorates rapidly. Therefore, it is important to extend the shelf life after harvest. In this study, putrescine and modified atmosphere packaging (MAP) were applied during cold storage in order to maintain the quality and extend the shelf life of strawberry fruit. The commercial ripening fruit were treated with 1 mM putrescine and stored in MAP for 20 days. The quality characteristics such as weight loss, soluble solids content, titratable acidity, fruit color, organic acid and phenolic content were measured and analyzed on days 4, 8, 12, 16 and 20 of storage. At the end of 20 days of the cold storage, the highest weight loss was in control treatment (%). The decrease in soluble solids content (SSC) and titratable acidity (TA) values during cold storage was slowed down by MAP and putrescine treatments. Organic acids and phenolic compounds were significantly affected by storage time and MAP and putrescine treatments. After 20 days of the cold storage, citric acid (748.91 mg 100 g -1) and malic acid (258.34 mg 100 g-1), which were determined as basic organic acids, were highest in putrescine treatment. Shikimic acid (0.77 mg 100 g-1) and isocitric acid (112.58 mg 100 g-1) as phenolic compounds were highest in MAP and MAP+ putrescine treatments, respectively. These results releaved that the application of putrescine and modified atmosphere packaging (MAP) during cold storage significantly extends the market life of strawberries by preserving their quality attributes.

Thermoforming Vacuum Packaging Influences Fresh Pork Loin Chop Characteristics.

The storage duration of fresh meat products is a contributing factor leading to increased waste and loss at the retail counter. Losses of fresh pork can be linked to packaging methods that do not protect the attributes of color, taste, and odors consumers use in determining wholesome meat. Boneless pork loins (N = 63) were fabricated into 2.54-cm-thick chops and assigned to one of three vacuum treatments (VacA, VacB, VacC) or a fourth polyvinyl chloride overwrap (PVC) treatment to assess objective fresh color, cook loss, Warner-Bratzler shear force (WBSF), and lipid oxidation. Pork chops (n = 882) were evaluated at 5-day intervals (D 0, 5, 10, 15) in a randomized complete block design. Pork chop surface color was lighter (L*; p < 0.0001) when stored in a vacuum compared to PVC-packaged loin chops, regardless of storage duration. Redness (a*) values were greater (p < 0.0001) for loin chops stored in PVC than all other vacuum packaging treatments throughout the entire 15-day display period. Relative values for chroma on PVC-packaged loin chops were greater (p < 0.0001) throughout the simulated retail display period. An interaction of day and packaging treatment (p < 0.0343) occurred for WBSF. Lipid oxidation for pork chops packaged using PVC was significantly greater (p < 0.0001) from Day 10 through the completion of the storage period. Results indicate that vacuum packaging limits the deterioration of fresh pork loin chops, whereas traditional overwrapping expedites the color and lipid oxidation during refrigerated storage.

Effect of 1-MCP and KMnO4 treatments with different packaging on quality preservation of golden delicious apples

This study explored the impact of three packaging materials (wooden boxes, corrugated fiber boxes, shrink-wrapped boxes) combined with two ethylene scrubbers (1-MCP, KMnO4) on the shelf life of Golden Delicious apples. While previous research has extensively studied the effects of packaging and ethylene inhibitors independently, the novelty of this work lies in its combined evaluation of these factors under ambient storage conditions over an extended period of 160 days. The study specifically addresses a research gap by directly comparing the efficacy of 1-MCP and KMnO4 within different packaging environments, offering insights into their combined influence on key quality parameters such as firmness, juice yield, rot incidence, physiological loss in weight (PLW), acidity, and total soluble solids (TSS). Findings revealed that 1-MCP-treated apples, particularly when shrink-wrapped, experienced minimal reductions in firmness and juice yield, with significantly lower rot incidence and physiological loss in weight (PLW) compared to KMnO4-treated and control apples. Additionally, while acidity and juice content naturally declined over time, and TSS initially increased before decreasing, 1-MCP-treated apples exhibited more stable quality attributes. The study also noted a slower decline in organoleptic quality with 1-MCP and shrink-wrap packaging. The research concludes that the combination of 1-MCP treatment and shrink-wrap packaging most effectively extends the shelf life of Golden Delicious apples, highlighting the importance of integrated approaches to post-harvest management. This study provides a novel framework for improving storage techniques, particularly for ambient conditions where shelf life extension is most challenging.

Deciphering Factors Contributing to Cost-Effective Medicine Using Machine Learning.

This study uses machine learning to identify critical factors influencing the cost-effectiveness of over-the-counter (OTC) medications. By developing a novel cost-effectiveness rating (CER) based on user ratings and prices, we analyzed data from Amazon. The findings indicate that Flexible Spending Account (FSA)/Health Savings Account (HSA) eligibility, symptom treatment range, safety warnings, special effects, active ingredients, and packaging size significantly impact cost-effectiveness across cold, allergy, digestion, and pain relief medications. Medications eligible for FSA or HSA funds, treating a broader range of symptoms, and having smaller packaging are perceived as more cost-effective. Cold medicines with safety warnings were cost-effective due to their lower average price and effective ingredients like phenylephrine and acetaminophen. Allergy medications with kid-friendly features showed higher cost-effectiveness, and ingredients like calcium, famotidine, and magnesium boosted the cost-effectiveness of digestion medicines. These insights help consumers make informed purchasing decisions and assist manufacturers and retailers in enhancing product competitiveness. Overall, this research supports better decision-making in the pharmaceutical industry by highlighting factors that drive cost-effective medication purchases.

Applications of biotechnology for enhancing the shelf life of horticultural crops

AbstractHorticultural crops, encompassing fruits, vegetables, spices and herbs, play a critical role in providing nutrition and health‐promoting compounds. However, their limited storability challenges producers and exporters, resulting in significant postharvest losses. Traditional preservation methods like cold storage, controlled atmosphere storage and packaging techniques have been employed to prolong shelf life, but they have their constraints. Biotechnological interventions, notably genetic engineering, offer promising avenues to address these limitations. Genetic modifications target physiological processes such as ripening and ethylene production, enhancing resistance to postharvest diseases and improving nutritional profiles. For instance, genetically modified tomatoes with prolonged shelf life and reduced susceptibility to fungal infections showcase the potential of genetic engineering. Similarly, genetic modification has been successfully applied to various horticultural crops like apples, bananas and mushrooms, resulting in decreased browning and heightened disease resistance. Emerging technologies such as modified atmosphere packaging, edible coatings and nanoparticle treatments further augment efforts to extend shelf life. Despite their benefits, the debate surrounding genetically modified fruits and vegetables persists due to concerns regarding environmental impact, health implications and ethical considerations. This review offers insights into current practices and research endeavours aimed at enhancing the shelf life of horticultural crops through both traditional and biotechnological means, shedding light on opportunities and hurdles in this domain. Future directions include intensifying basic research to unravel molecular processes in harvested tissues, prioritising investigations that directly benefit consumers and developing sustainable and cost‐effective approaches for emerging technologies like modified atmosphere packaging, edible coatings and postharvest treatments.

Effects of in-package cold plasma treatment on poultry breast meat packaged in high CO2 atmosphere

High CO2 in packages significantly extends microbiological shelf life of poultry meat. Cold plasma is an emerging antimicrobial treatment, which generates various reactive gas species and inactivates microbials effectively. The objective of this study was to explore the potential effects of combining high CO2 package and in-package cold plasma (IPCP) treatments on the quality and safety of raw chicken breast meat. Non-inoculated samples and samples inoculated with Campylobacter jejuni and Salmonella Typhimurium were packaged in 0, 30, 70, or 100% CO2 (with make-up gas N2) and treated with IPCP at 70 kV for 3 min. Ozone formation, microbial counts, drip loss, pH, and color were measured. There was no interaction effect between high CO2 package and IPCP on microbial counts, drip loss, and color measurements. IPCP reduced spoilage microbial growth by 0.43 log (from 7.00 log to 6.57 log, P = 0.033) and C. jejuni populations by 0.67 log (from 4.82 log to 4.15 log, P < 0.001) on meat surface but did not affect S. Typhimurium (P = 0.206). Increased CO2 in packages had more effect on spoilage microbial growth (more than 1.5 log from 8.08 log to 6.35 log, P < 0.001) and S. Typhimurium populations (more than 0.5 log from 4.94 log to 4.39 log, P = 0.004) than IPCP but did not affect C. jejuni (P = 0.163). IPCP resulted in increases in changes in L* by 1.67 units (0.70 versus 2.37, P = 0.016) and a* values by 0.56 units (0.73 versus 1.29, P < 0.001) and decreases in b* values by 0.91 units (0.46 versus -0.45, P = 0.015). High CO2 levels caused increases in changes in L* values by 4.35 units (-0.82 versus 3.53, P < 0.001) with no effects on a* and b* values (P > 0.05). Data demonstrate that there are no combined effects by high CO2 package and IPCP on meat quality and safety of raw chicken breast meat under our experimental conditions. Either high CO2 package or IPCP can retain microbial quality and safety, even though they may cause changes in appearance of stored chicken breast meat.

Highly efficient capture of Escherichia coli using chitosan-lysozyme modified nanofiber membranes: Potential applications in food packaging and water treatment

Highly efficient capture of Escherichia coli using chitosan-lysozyme modified nanofiber membranes: Potential applications in food packaging and water treatment

Preparation of chitosan/Tenebrio molitor larvae protein/curcumin active packaging film and its application in blueberry preservation

With growing concerns about postharvest spoilage of fruits, higher requirements have been placed on high-performance and sustainable active packaging materials. In this study, we prepared curcumin-based functional composite films using chitosan (CS) and Tenebrio molitor larvae protein (TMP) as the substrates. The effects of curcumin concentration on the structural and physicochemical properties of the composite films were determined. Curcumin was equally distributed in the polymer film through physical interactions. Furthermore, the curcumin composite film with 0.3 % addition exhibited a 27.39 % increase in elongation at break (EBA), a 37.04 % increase in the water vapor barrier, and strong UV-blocking properties and antioxidant activity compared with the control film (CS/TMP). The degradation experiment of the composite film on natural soil revealed that the composite film exhibited good biodegradability and environmental protection. Furthermore, the applicability of functional composite films for preserving blueberries was investigated. Compared with the control film and polyethylene (PE) films, the prepared composite films packaging treatment reduced the decay rate and weight loss rate of blueberries during storage, delayed softening and aging, and maintained the quality of blueberries. Using sustainable protein resources (TMP) and natural polysaccharides as packaging materials provides an economically, feasible and sustainable way to achieve the functional preservation of biomass materials.

Treatment efficiency and recovery in sand filters for on-site wastewater treatment: Column studies and reactive modelling

This study examined the adsorption capacity and treatment efficiency of sand filters in on-site treatment systems for cold climate regions. The effects of different operating conditions, porosity and kinetics parameters were investigated in column experiments and COMSOL Multiphysics® modelling, to comprehensively reveal the mechanisms and optimize treatment efficiency of nitrogen (N) and phosphorus (P) removal in a field tidal flow constructed wetland (TFCW), treating effluent from a package treatment plant with P filter material. The results from column experiments with sand showed that Total-P adsorption rate was dependent on feed water quality (Septic tank >0.77 ± 0.06 g kg−1; Biotreatment >0.41 ± 0.07 g kg−1; Reactive material Polonite® <0.18 ± 0.07 g kg−1). In the field TFCW trial, Total-P adsorption in the top layer (>1.42 ± 0.55 g kg−1) and middle layer (>1.06 ± 0.51 g kg−1) was twice that in laboratory columns, due to strong interaction with the air-water interface and use of fluctuated domestic wastewater solutions. The breakthrough curve (BTCs) of the coarse sand matched the physical behaviour of tracer electrical conductivity (EC) in effluent from the sand column experiments. The modelling results demonstrated that high filter porosity and low hydraulic load were significant factors for optimal removal of NH4–N, Total-N, PO4–P, Total- P in the top layer (>99.95 ± 0.03 %, 44.37 ± 28.75%, 70.89 ± 28.30%, 76.18 ± 20.3%), middle layer (>98.94 ± 1.77%, 18.23 ± 23.04%, 76.62 ± 28.73%, 65.40 ± 31.85%) and deep layer (>99.99 ± 0.02%, 65.50 ± 20.64%, 75.53 ± 23.16%, 41.54 ± 28.81%) in the TFCW system, respectively. The results show that on-site wastewater treatment in cold climate TFCW can be applied as a technology to polish effluent from a three-step pretreatment system. However, hydraulic optimization is an important factor for the design of the TFCW to receive a successful long-term operating system.

A Sustainable Material for Sheep's Cheese Wedges Stored under Different Atmosphere Conditions.

This study is based on the need to improve packaging sustainability in the food industry. Its aim was to assess the performance of a recyclable plastic material for semi-hard sheep's cheese wedges packaging as an alternative to conventional non-sustainable plastic materials. Four different packaging treatments (air, vacuum, and CO2/N2 gas mixtures 50/50 and 80/20% (v/v)) were studied. Changes in gas headspace composition, sensory properties, cheese gross composition, weight loss, pH, colour, and texture profile were investigated at 5 ± 1 °C storage for 56 days. The sensory analysis indicated that vacuum packaging scored the worst in paste appearance and holes, and air atmosphere the worst in flavour; it was concluded that cheeses were unfit from day 14-21 onwards. Air and vacuum packaging were responsible for most of the significant changes identified in the texture profile analysis, and most of these happened in the early stages of storage. The colour parameters a* and b* differentiated the air packaging from the rest of the conditions. As in previous studies using conventional plastic materials, modified atmosphere packaging, either CO2/N2 50/50 or 80/20% (v/v), was the most effective preserving technique to ensure the quality of this type of cheese when comparing air and vacuum packaging treatments.

Progress of silver-loaded cellulose composite antimicrobial materials

Silver-loaded cellulose composite antimicrobial materials have become a hot spot in the field of scientific research due to their excellent antimicrobial properties, good biocompatibility and environmental friendliness. The preparation methods include in situ chemical reduction, hydrothermal reduction, sol-gel and electrostatic self-assembly. These materials achieve antibacterial effects through mechanisms such as disrupting bacterial cell walls, inhibiting enzyme and protein activity, and disrupting bacterial DNA, and have broad application prospects in medical, packaging, and water treatment fields. This article provides a detailed summary of the research progress in the preparation methods, antibacterial mechanisms, and applications of silver loaded cellulose composite antibacterial materials, and looks forward to future research trends.

Forage-cactus based edible coating, packaging, and refrigeration improve the visual and nutraceutical qualities of sweet potatoes

Sweet potatoes have high economic relevance in developing countries. Therefore, the adoption of post-harvest technologies for their conservation for long-distance markets is crucial. In this work, the effect of the combined use of cactus-based edible coating, packaging and refrigeration on the quality of sweet potatoes was evaluated. Four coating and packaging treatments were evaluated: (Control, Coating, Packaging, and Packaging + Coating) and seven storage periods (0, 7, and 14 days at 8 °C, and 17, 20, 23, and 26 days at 23 °C simulate refrigerated transport and shelf conditions respectively). Coating treatments consisted of immersion in 0.04 g L−1 of forage cactus mucilage + 300 mL L−1 glycerol for 1 min. After 14 days of cold storage, sweet potatoes were maintained at 23 °C for up to 26 days. Raw and cooked (microwaved for five minutes) sweet potato samples were evaluated at 0, 7, 14, 17, 20, 23, and 26 days. The refrigerated condition maintained sweet potato quality based on visual analysis for up to 14 days, regardless of the use of the edible coating. However, only packaged sweet potatoes, with or without coating, maintained higher visual scores after transfer to room conditions, exhibiting lower fresh weight loss up to 26 days. Sweet potatoes subjected only to edible coating maintained an acceptable visual appearance until 23 days. Additionally, firmness, visual analysis, DPPH and FRAP antioxidant activity, soluble phenolic and starch contents were more stable in raw and cooked sweet potatoes packaged (with or without coating) for up to 26 days, which is a sufficient time to reach more distant markets.

Hierarchically synthesis of M@CeO2 (M = Ba, Er) nanoparticles for Antibacterial efficacy

Cerium oxide fine particles injected with metallic nanoparticles were produced using the co-precipitation method and characterized using various techniques such as XRD, SEM, FTIR, UV–Vis, and PL. Both injected and non-doped ceria nanoparticles exhibited a crystallographic structure similar to calcium fluoride. The nanoparticles ranged in size from 25 to 74 nm and had an inconsistent spherical shape. EDX analysis confirmed the presence of Erbium (Er) and Barium (Ba) in the ceria nanocrystal lattices. UV–Vis experiments showed that the optical band gap efficiency of purified CeO2 NPs was 3.1 eV, while doped CeO2 NPs had an energy level of 2.9 eV. The nanoparticles exhibited a sharp emission peak at approximately 347 nm. The synthesized CeO2 NPs showed antibacterial activity against Gram-positive and Gram-negative bacteria, including Bacillus subtilis, Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa. Overall, the results demonstrate that the doping of ceria nanoparticles with metallic nanoparticles can significantly enhance their antibacterial properties. This research paves the way for the development of novel antibacterial agents with potential applications in various fields such as medicine, food packaging, and water treatment.

Investigation of the control of Sitophilus granarius in stored grain using vacuum packaging and the creation of an anaerobic atmospheric environment

The efficacy of vacuum and oxygen absorption-based treatments for controlling Sitophilus granarius L. damage in wheat grains was compared under laboratory conditions. The efficacy of the treatments was evaluated at different temperature ranges (−5, 26, 42 °C) and exposure times (0.5, 1, 3, 6, 24, 48, 72 h). Treatment-survived adult progeny were measured on day 45. Our studies demonstrated that the efficacy of the controlled atmosphere methods (CAs) we tested varied significantly as a function of time. While the mortality curve induced by the different temperature-controlled low-pressure vacuum packaging treatments is logarithmic, the mortality trend induced by the absorber's low oxygen levels follows an exponential slope. The hypoxia induced by low oxygen levels has a much longer duration of action. We have shown that vacuum packaging at lower and higher pessimum temperature ranges other than the thermal optimum of the insect induced significant mortality of S. granarius. The method was particularly effective when vacuum-packed items were kept at a higher pessimum temperature range. Our results confirm that vacuum packaging based on atmospheric modification, especially at elevated temperatures, can be a sustainable solution for pest control of small volume, valuable seed samples.

Comparative study of nonlinear thermal convection on magnetized dissipative flow along a shrinking Riga sheet with entropy generation

The concept of nonlinear thermal convection is taking place for the process of cooling/heating in some thermal industries like solar collectors, combustion, and reactor safety. The significance of linear and nonlinear thermal convection is implemented in the present mathematical modeling to handle nonlinear density-temperature caused by viscous dissipation and flow through a porous medium. Further, the inclined magnetic field is implemented to analyze the flow characteristic at various inclination angles which will be helpful in glass manufacturing, geophysics, crude oil purification, and paper production. Furthermore, entropy generation analysis is made for the stagnation point flow of viscous fluid over a shrinking Riga sheet. Using boundary layer assumptions, the present model made up of fluid motion and energy equations is formed and converted to a system of nonlinear differential equations. Numerical results are collected using the MATLAB bvp4c solver and these results were utilized to study important parameters on the entropy generation and heat transport of fluid flow. The presence of nonlinear thermal convection will intensify the impact of major parameters and the least entropy generated for the inclination angle of the magnetic field. Also, entropy enhanced significantly with the Eckert number and modified Hartmann number. In addition, the surface drag is enhanced by 12%-18 % and the thermal transmission rate is diminished by 4%-7% in the case of nonlinear thermal convection compared to the linear case. The findings of this study are more important to optimize heat transfer and irreversibility in the applications of the automotive industry, ceramics, paints, food packaging, fabrics, pharmaceuticals, and cancer treatment.

Recent Progresses in Pyrolysis of Plastic Packaging Wastes and Biomass Materials for Conversion of High-Value Carbons: A Review.

The recycling of plastic packaging wastes helps to alleviate the problems of white pollution and resource shortage. It is very necessary to develop high-value conversion technologies for plastic packaging wastes. To our knowledge, carbon materials with excellent properties have been widely used in energy storage, adsorption, water treatment, aerospace and functional packaging, and so on. Waste plastic packaging and biomass materials are excellent precursor materials of carbon materials due to their rich sources and high carbon content. Thus, the conversion from waste plastic packaging and biomass materials to carbon materials attracts much attention. However, closely related reviews are lacking up to now. In this work, the pyrolysis routes of the pyrolysis of plastic packaging wastes and biomass materials for conversion to high-value carbons and the influence factors were analyzed. Additionally, the applications of these obtained carbons were summarized. Furthermore, the limitations of the current pyrolysis technology are put forward and the research prospects are forecasted. Therefore, this review can provide a useful reference and guide for the research on the pyrolysis of plastic packaging wastes and biomass materials and the conversion to high-value carbon.