Effect of plasma treatment on improving liquid retention capacity of capillary recesses for food packaging applications

AbstractThe internal architecture of chambered ammonoid conchs profoundly increased in complexity through geologic time, but the adaptive value of these structures is disputed. Specifically, these cephalopods developed fractal-like folds along the edges of their internal divider walls (septa). Traditionally, functional explanations for septal complexity have largely focused on biomechanical stress resistance. However, the impact of these structures on buoyancy manipulation deserves fresh scrutiny. We propose increased septal complexity conveyed comparable shifts in fluid retention capacity within each chamber. We test this interpretation by measuring the liquid retained by septa, and within entire chambers, in several 3D-printed cephalopod shell archetypes, treated with (and without) biomimetic hydrophilic coatings. Results show that surface tension regulates water retention capacity in the chambers, which positively scales with septal complexity and membrane capillarity, and negatively scales with size. A greater capacity for liquid retention in ammonoids may have improved buoyancy regulation, or compensated for mass changes during life. Increased liquid retention in our experiments demonstrate an increase in areas of greater surface tension potential, supporting improved chamber refilling. These findings support interpretations that ammonoids with complex sutures may have had more active buoyancy regulation compared to other groups of ectocochleate cephalopods. Overall, the relationship between septal complexity and liquid retention capacity through surface tension presents a robust yet simple functional explanation for the mechanisms driving this global biotic pattern.

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Poly(3-hydroxybutyrate) Modified by Nanocellulose and Plasma Treatment for Packaging Applications

Polymers ◽

10.3390/polym10111249 ◽

2018 ◽

Vol 10 (11) ◽

pp. 1249 ◽

Cited By ~ 16

Author(s):

Denis Mihaela Panaitescu ◽

Eusebiu Rosini Ionita ◽

Cristian-Andi Nicolae ◽

Augusta Raluca Gabor ◽

Maria Daniela Ionita ◽

...

Keyword(s):

Staphylococcus Aureus ◽

Antibacterial Activity ◽

Plasma Treatment ◽

Food Packaging ◽

Cellulose Nanofibers ◽

Plasma Coating ◽

Melting Behavior ◽

Zno Nanoparticle ◽

Melt Compounding ◽

Green Solution

In this work, a new eco-friendly method for the treatment of poly(3-hydroxybutyrate) (PHB) as a candidate for food packaging applications is proposed. Poly(3-hydroxybutyrate) was modified by bacterial cellulose nanofibers (BC) using a melt compounding technique and by plasma treatment or zinc oxide (ZnO) nanoparticle plasma coating for better properties and antibacterial activity. Plasma treatment preserved the thermal stability, crystallinity and melting behavior of PHB‒BC nanocomposites, regardless of the amount of BC nanofibers. However, a remarkable increase of stiffness and strength and an increase of the antibacterial activity were noted. After the plasma treatment, the storage modulus of PHB having 2 wt % BC increases by 19% at room temperature and by 43% at 100 °C. The tensile strength increases as well by 21%. In addition, plasma treatment also inhibits the growth of Staphylococcus aureus and Escherichia coli by 44% and 63%, respectively. The ZnO plasma coating led to important changes in the thermal and mechanical behavior of PHB‒BC nanocomposite as well as in the surface structure and morphology. Strong chemical bonding of the metal nanoparticles on PHB surface following ZnO plasma coating was highlighted by infrared spectroscopy. Moreover, the presence of a continuous layer of self-aggregated ZnO nanoparticles was demonstrated by scanning electron microscopy, ZnO plasma treatment completely inhibiting growth of Staphylococcus aureus. A plasma-treated PHB‒BC nanocomposite is proposed as a green solution for the food packaging industry.

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Characterization of polyvinyl alcohol-borax/agarose (PVA-B/AG) double network hydrogel utilized for the cleaning of works of art

10.21203/rs.3.rs-48527/v3 ◽

2020 ◽

Author(s):

Ehab Awad Al-Emam ◽

Hilde Soenen ◽

Joost Caen ◽

Koen Janssens

Keyword(s):

Polyvinyl Alcohol ◽

Self Healing ◽

Retention Capacity ◽

Structured Surfaces ◽

Double Network ◽

Liquid Retention ◽

Long Time ◽

Cleaning Procedures ◽

Phase Retention

Abstract Since cleaning of artworks may cause undesirable physicochemical alterations and is a nonreversible procedure, it is mandatory to adopt the proper cleaning procedure. Such a procedure should remove undesired materials whilst preserving the original surface. In this regard, numerous gels have been developed and exploited for the cleaning of various artwork surfaces. Lately, agarose (AG) and polyvinyl alcohol-borax (PVA-B) hydrogels have been widely employed as cleaning tools by conservators. Both hydrogels show some limitations in specific cleaning practices. In this work, we investigated the influence of including increased levels of agarose into PVA-B systems. For this reason, we performed a detailed characterization on the double network (DN) hydrogel including the chemical structure, the liquid phase retention, the rheological behavior, and the self-healing behavior of various PVA-B/AG double network hydrogels. These new hydrogels revealed better properties than PVA-B hydrogels and obviated their limitations. The inclusion of AG into PVA-B systems enhanced the liquid retention capacity, shape-stability, and mechanical strength of the blend. Furthermore, AG minimized the expelling/syneresis issue that occurs when loading PVA-B systems with low polarity solvents or chelating agents. The resultant double network hydrogel exhibits relevant self-healing properties. The PVA-B/AG double network is a new and useful cleaning tool that can be added to the conservators’ tool-kit. It is ideal for cleaning procedures dealing with porous and complex structured surfaces, vertical surfaces and for long time applications.

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Effect of Radio Frequency Cold Plasma Treatment on Intermediate Wheatgrass (Thinopyrum intermedium) Flour and Dough Properties in Comparison to Hard and Soft Wheat (Triticum aestivum L.)

Journal of Food Quality ◽

10.1155/2019/1085172 ◽

2019 ◽

Vol 2019 ◽

pp. 1-8 ◽

Cited By ~ 5

Author(s):

Sophie Held ◽

Catrin E. Tyl ◽

George A. Annor

Keyword(s):

Plasma Treatment ◽

Cold Plasma ◽

Soft Wheat ◽

Thinopyrum Intermedium ◽

Retention Capacity ◽

Intermediate Wheatgrass ◽

Hard Wheat ◽

Protein Secondary Structures ◽

Solvent Retention ◽

Solvent Retention Capacity

Cold plasma is an emerging technology to improve microbiological safety as well as functionality of foods. This study compared the effect of radio frequency cold plasma on flour and dough properties of three members of the Triticeae tribe, soft as well as hard wheat (Triticum aestivum L.) and intermediate wheatgrass (Thinopyrum intermedium, IWG). These three flour types differ in their protein content and composition and were evaluated for their solubility, solvent retention capacity, starch damage, GlutoPeak and Farinograph profiles, and protein secondary structures. Plasma treatment resulted in dehydration of flours but did not change protein content or solubility. Farinograph water absorption increased for all flours after plasma treatment (from 56.5–61.1 before to 71.0–81.6%) and coincided with higher solvent retention capacity for water and sodium carbonate. Plasma treatment under our conditions was found to cause starch damage to the extent of 3.46–6.62% in all samples, explaining the higher solvent retention capacity for sodium carbonate. However, Farinograph properties were changed differently in each flour type: dough development time and stability time decreased for hard wheat and increased for soft wheat but remained unchanged in intermediate wheatgrass. GlutoPeak parameters were also affected differently: peak torque for intermediate wheatgrass increased from 32 to 39.5 GlutoPeak units but was not different for the other two flours. Soft wheat did not always aggregate after plasma treatment, i.e., did not aggregate within the measurement time. It was also the only flour where protein secondary structures were changed after plasma treatment, exhibiting an increase from 15.2 to 27.9% in β-turns and a decrease from 59.4 to 47.9% in β-sheets. While this could be indicative of a better hydrated gluten network, plasma-treated soft wheat was the only flour where viscoelastic properties were changed and extensibility decreased. Further research is warranted to elucidate molecular changes underlying these effects.

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Characterization of polyvinyl alcohol-borax/agarose (PVA-B/AG) double network hydrogel utilized for the cleaning of works of art

10.21203/rs.3.rs-48527/v2 ◽

2020 ◽

Author(s):

Ehab Awad Al-Emam ◽

Hilde Soenen ◽

Joost Caen ◽

Koen Janssens

Keyword(s):

Polyvinyl Alcohol ◽

Self Healing ◽

Retention Capacity ◽

Structured Surfaces ◽

Double Network ◽

Liquid Retention ◽

Long Time ◽

Cleaning Procedures ◽

Phase Retention

Abstract Since cleaning of artworks may cause undesirable physicochemical alterations and is a nonreversible procedure, it is mandatory to adopt the proper cleaning procedure. Such a procedure should remove undesired materials whilst preserving the original surface. In this regard, numerous gels have been developed and exploited for the cleaning of various artwork surfaces. Lately, agarose (AG) and polyvinyl alcohol-borax (PVA-B) hydrogels have been widely employed as cleaning tools by conservators. Both hydrogels show some limitations in specific cleaning practices. In this work, we investigated the influence of including increased levels of agarose into PVA-B systems. For this reason, we performed a detailed characterization on the double network (DN) hydrogel including the chemical structure, the liquid phase retention, the rheological behavior, and the self-healing behavior of various PVA-B/AG double network hydrogels. These new hydrogels revealed better properties than PVA-B hydrogels and obviated their limitations. The inclusion of AG into PVA-B systems enhanced the liquid retention capacity, shape-stability, and mechanical strength of the blend. Furthermore, AG minimized the expelling/syneresis issue that occurs when loading PVA-B systems with low polarity solvents or chelating agents. The resultant double network hydrogel exhibits relevant self-healing properties. The PVA-B/AG double network is a new and useful cleaning tool that can be added to the conservators’ tool-kit. It is ideal for cleaning procedures dealing with porous and complex structured surfaces, vertical surfaces and for long time applications.

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Evaluation of liquid retention capacity measurements as a tool for estimating optimal ore agglomeration moisture content

International Journal of Mineral Processing ◽

10.1016/j.minpro.2012.12.005 ◽

2013 ◽

Vol 119 ◽

pp. 58-64 ◽

Cited By ~ 7

Author(s):

Thien Vethosodsakda ◽

Michael L. Free ◽

Adirek Janwong ◽

Michael S. Moats

Keyword(s):

Moisture Content ◽

Retention Capacity ◽

Liquid Retention

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New Trends in the Use of Volatile Compounds in Food Packaging

Polymers ◽

10.3390/polym13071053 ◽

2021 ◽

Vol 13 (7) ◽

pp. 1053

Author(s):

Ana Beltrán Sanahuja ◽

Arantzazu Valdés García

Keyword(s):

Volatile Compounds ◽

Food Packaging ◽

Active Agent ◽

Retention Capacity ◽

Polymeric Matrices ◽

Factors Affecting ◽

Active Food Packaging ◽

High Volatility ◽

Recent Trends ◽

Packaging Industry

In the last years, many of the research studies in the packaging industry have been focused on food active packaging in order to develop new materials capable of retaining the active agent in the polymeric matrix and controlling its release into food, which is not easy in many cases due to the high volatility of the chemical compounds, as well as their ease of diffusion within polymeric matrices. This review presents a complete revision of the studies that have been carried out on the incorporation of volatile compounds to food packaging applications. We provide an overview of the type of volatile compounds used in active food packaging and the most recent trends in the strategies used to incorporate them into different polymeric matrices. Moreover, a thorough discussion regarding the main factors affecting the retention capacity and controlled release of volatile compounds from active food packaging is presented.

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Characterization of polyvinyl alcohol-borax/agarose (PVA-B/AG) double network hydrogel utilized for the cleaning of works of art

10.21203/rs.3.rs-48527/v1 ◽

2020 ◽

Author(s):

Ehab Awad Al-Emam ◽

Hilde Soenen ◽

Joost Caen ◽

Koen Janssens

Keyword(s):

Polyvinyl Alcohol ◽

Rheological Behaviour ◽

Self Healing ◽

Retention Capacity ◽

Structured Surfaces ◽

Double Network ◽

Liquid Retention ◽

Long Time ◽

Cleaning Procedures ◽

Phase Retention

Abstract Since cleaning of artworks is a nonreversible procedure, it is mandatory to adopt the proper cleaning technique which has the ability to remove undesired materials whilst preserving the original surface and, if present, the original ‘patina’ of the surface layer. In this regard, numerous gels have been developed and exploited for the cleaning of various artwork surfaces. Lately, agarose (AG) and polyvinyl alcohol-borax (PVA-B) hydrogels have been widely employed as cleaning tools by conservators-restorers. Both hydrogels show some limitations in specific cleaning practices. In this work, we investigated the influence of including increased levels of agarose into PVA-B systems. For this reason, we performed a detailed characterization on the double network (DN) hydrogel including the chemical structure, the liquid phase retention, the rheological behaviour, and the self-healing behaviour of various PVA-B/AG double network hydrogels. These new hydrogels revealed better properties than PVA-B hydrogels and obviated their limitations. The inclusion of AG into PVA-B systems enhanced the liquid retention capacity, shape-stability, and mechanical strength of the blend. Furthermore, AG minimized the expelling/syneresis issue that occurs when loading PVA-B systems with non-polar solvents or chelating agents. The resultant double network hydrogel exhibits relevant self-healing properties. The PVA-B/AG double network is a new and useful cleaning tool that can be added to the conservators-restorers’ tool-kit. It is ideal for cleaning procedures dealing with porous and complex structured surfaces, vertical surfaces and for long time applications.

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Bioremediation of crude oil-bearing soil: Evaluation of rhamnolipid addition as for the toxicity and crude oil biodegradation efficiency

Global NEST Journal ◽

10.30955/gnj.000592 ◽

2013 ◽

Vol 11 (2) ◽

pp. 181-188

Keyword(s):

Seed Germination ◽

Crude Oil ◽

Toxicity Tests ◽

Soil Environment ◽

Retention Capacity ◽

Soil Evaluation ◽

Liquid Retention ◽

Oil Biodegradation ◽

Hydrocarbon Removal ◽

Rhamnolipid Biosurfactant

This work is aimed at evaluating the potentiality of adding a rhamnolipid biosurfactant in a petroleum-bearing soil. For this purpose, dehydrogenase activity and seed germination (Lactuca sativa) testes were performed before the biodegradation assays with different concentrations of rhamnolipid (1 to 15mg for 1g of soil). The addition of 1 and 15 mg g-1 of rhamnolipid was harmful to the soil environment. The biodegradation assays were carried out at room temperature during 45 days in bioreactors containing 450g of a polluted soil with different rhamnolipid concentrations varying from 1 to 15 mg g-1. The nutrients were corrected through the addition of NH4NO3 and KH2PO4, in a nutritional ratio of C:N:P=100:15:1. The humidity was adjusted to 50% of the liquid retention capacity. Besides these assays, a control test was conducted without adding rhamnolipid. TPH (Total petroleum hydrocarbon) removal and seed germination were evaluated at the end of these experiments. When 4 mg g-1 of rhamnolipid were used a TPH removal of about 60% was observed. The biosurfactant addition improved all treatments, except for the assays with addition of 1 and 15 mg g-1 in which a decrease of the bioremediations rates was observed in the toxicity tests.

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Synthesis of Sodium Alginate–Silver Nanocomposites Using Plasma Activated Water and Cold Atmospheric Plasma Treatment

Nanomaterials ◽

10.3390/nano11092306 ◽

2021 ◽

Vol 11 (9) ◽

pp. 2306

Author(s):

Nusrat Sharmin ◽

Chengheng Pang ◽

Izumi Sone ◽

James Leon Walsh ◽

Cecilia Górriz Fernández ◽

...

Keyword(s):

Plasma Treatment ◽

Sodium Alginate ◽

Food Packaging ◽

Tensile Modulus ◽

Atmospheric Plasma ◽

Nanocomposite Films ◽

Solution Viscosity ◽

Vis Spectroscopy ◽

Average Size ◽

Plasma Activated Water

In this study, sodium alginate (SA)-based, eco-friendly nanocomposites films were synthesized for potential food packaging applications using silver nitrate (AgNO3) as the metal precursor, reactive nitrogen and oxygen species (RNOS) created within plasma activated water (PAW), or through cold plasma treatment (CP) as reducing agent and SA as stabilizing agent. The formation of silver nanoparticles (AgNPs) was confirmed via the absorption peaks observed between 440 and 450 nm in UV-vis spectroscopy. The tensile strength (TS) and tensile modulus (TM) of the nanocomposite films were significantly higher than those of the SA films. An increase in the TS was also observed as the AgNP concentration was increased from 1 to 5 mM. The storage modulus (G’) of the nanocomposite solution was higher than that of the SA solution. The synthesis of AgNPs resulted both in a higher solution viscosity and a more marked shear-thinning effect. The synthesized AgNPs showed antimicrobial activity against both Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) bacteria. The AgNPs were spherical in shape with an average size of 22 nm.

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