scholarly journals Mechanical and Antimicrobial Polyethylene Composites with CaO Nanoparticles

Polymers ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2132
Author(s):  
Cristián Silva ◽  
Felipe Bobillier ◽  
Daniel Canales ◽  
Francesca Antonella Sepúlveda ◽  
Alejandro Cament ◽  
...  
Keyword(s):  
Surface Modification ◽  
Polymer Nanocomposites ◽  
Food Packaging ◽  
Sol Gel ◽  
Antimicrobial Effect ◽  
Nucleating Agents ◽  
Ion Release ◽  
Melt Mixing ◽  
Escherichia Coli Bacteria ◽  
Polyethylene Composites

Low-density polyethylene composites containing different sizes of calcium oxide (CaO) nanoparticles were obtained by melt mixing. The CaO nanoparticles were synthesized by either the sol-gel or sonication methods, obtaining two different sizes: ca. 55 nm and 25 nm. These nanoparticles were used either as-synthesized or were modified organically on the surface with oleic acid (Mod-CaO), at concentrations of 3, 5, and 10 wt% in the polymer. The Mod-CaO nanoparticles of 25 nm can act as nucleating agents, increasing the polymer’s crystallinity. The Young’s Modulus increased with the Mod-CaO nanoparticles, rendering higher reinforcement effects with an increase as high as 36%. The reduction in Escherichia coli bacteria in the nanocomposites increased with the amount of CaO nanoparticles, the size reduction, and the surface modification. The highest antimicrobial behavior was found in the composites with a Mod-CaO of 25 nm, presenting a reduction of 99.99%. This strong antimicrobial effect can be associated with the release of the Ca2+ from the composites, as studied for the composite with 10 wt% nanoparticles. The ion release was dependent on the size of the nanoparticles and their surface modification. These findings show that CaO nanoparticles are an excellent alternative as an antimicrobial filler in polymer nanocomposites to be applied for food packaging or medical devices.

scholarly journals Synthesis of Silica Nanoparticles by Sol-Gel: Size-Dependent Properties, Surface Modification, and Applications in Silica-Polymer Nanocomposites—A Review

2012 ◽  
Vol 2012 ◽  
pp. 1-15 ◽  
Author(s):  
Ismail Ab Rahman ◽  
Vejayakumaran Padavettan
Keyword(s):  
Surface Modification ◽  
Silica Nanoparticles ◽  
Polymer Nanocomposites ◽  
Sol Gel ◽  
Chemical Properties ◽  
Size Dependent ◽  
Recent Developments ◽  
Gel Technique ◽  
Nanoparticles Characterization ◽  
Physical And Chemical

Application of silica nanoparticles as fillers in the preparation of nanocomposite of polymers has drawn much attention, due to the increased demand for new materials with improved thermal, mechanical, physical, and chemical properties. Recent developments in the synthesis of monodispersed, narrow-size distribution of nanoparticles by sol-gel method provide significant boost to development of silica-polymer nanocomposites. This paper is written by emphasizing on the synthesis of silica nanoparticles, characterization on size-dependent properties, and surface modification for the preparation of homogeneous nanocomposites, generally by sol-gel technique. The effect of nanosilica on the properties of various types of silica-polymer composites is also summarized.

Effect of Ion Release on Antibacterial Activity of Melt-Derived and Sol-Gel-Derived Reactive Ceramics

2006 ◽  
Vol 309-311 ◽  
pp. 349-354 ◽  
Author(s):  
Minna Vaahtio ◽  
Eveliina Munukka ◽  
Outi Leppäranta ◽  
Di Zhang ◽  
Erkki Eerola ◽  
...  
Keyword(s):  
Staphylococcus Epidermidis ◽  
Bacterial Adhesion ◽  
Antibacterial Effect ◽  
Sol Gel ◽  
Antimicrobial Effect ◽  
Melting Process ◽  
Ion Release ◽  
Ph Values ◽  
Ca Ions ◽  
Strong Antibacterial Effect

Four different bioreactive ceramics were prepared using a sol-gel method and a standard melting process. The aim was to study antibacterial effect of these materials on the growth of Staphylococcus epidermidis. The dissolution (Si and Ca ions) of fine (≤ 45 !m) ceramic powders in a tryptone soya broth (TSB) was investigated. Also the pH changes in TSB solution were measured. In addition the adherence of Enterococcus faecalis (Ef) to materials was investigated. The bacterial adhesion was studied using scanning electron microscopy (SEM). In the bacterial and the adhesion test, CaPSiO2 and S53P4 had the strongest antimicrobial effect against studied bacteria. It was shown that bioreactive sol-gel derived ceramic with sufficient high Ca ion release (> 270 ppm) can reach strong antibacterial effect also at lower pH values (< 9.6).

scholarly journals Nanocomposites for Food Packaging Applications: An Overview

Nanomaterials ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 10
Author(s):  
Jawad Sarfraz ◽  
Tina Gulin-Sarfraz ◽  
Julie Nilsen-Nygaard ◽  
Marit Kvalvåg Pettersen
Keyword(s):  
Polymer Nanocomposites ◽  
Circular Economy ◽  
Food Packaging ◽  
Antioxidant Properties ◽  
Nanocomposite Materials ◽  
Consumer Acceptability ◽  
Special Focus ◽  
Packaging Materials ◽  
Mechanical And Thermal Properties ◽  
Low Concentrations

There is a strong drive in industry for packaging solutions that contribute to sustainable development by targeting a circular economy, which pivots around the recyclability of the packaging materials. The aim is to reduce traditional plastic consumption and achieve high recycling efficiency while maintaining the desired barrier and mechanical properties. In this domain, packaging materials in the form of polymer nanocomposites (PNCs) can offer the desired functionalities and can be a potential replacement for complex multilayered polymer structures. There has been an increasing interest in nanocomposites for food packaging applications, with a five-fold rise in the number of published articles during the period 2010–2019. The barrier, mechanical, and thermal properties of the polymers can be significantly improved by incorporating low concentrations of nanofillers. Furthermore, antimicrobial and antioxidant properties can be introduced, which are very relevant for food packaging applications. In this review, we will present an overview of the nanocomposite materials for food packaging applications. We will briefly discuss different nanofillers, methods to incorporate them in the polymer matrix, and surface treatments, with a special focus on the barrier, antimicrobial, and antioxidant properties. On the practical side migration issues, consumer acceptability, recyclability, and toxicity aspects will also be discussed.

scholarly journals Synergistic Antimicrobial Activities of Combinations of Vanillin and Essential Oils of Cinnamon Bark, Cinnamon Leaves and Cloves

Foods ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1406
Author(s):  
Rita Cava-Roda ◽  
Amaury Taboada-Rodríguez ◽  
Antonio López-Gómez ◽  
Ginés Benito Martínez-Hernández ◽  
Fulgencio Marín-Iniesta
Keyword(s):  
Antimicrobial Activity ◽  
Essential Oils ◽  
Food Packaging ◽  
Antimicrobial Effect ◽  
Antimicrobial Activities ◽  
Inhibitory Effects ◽  
Cinnamon Bark ◽  
E Coli ◽  
Pure Compounds ◽  
Main Component

Plant bioactive compounds have antimicrobial and antioxidant activities that allow them to be used as a substitute for synthetic chemical additives in both food and food packaging. To improve its sensory and bactericidal effects, its use in the form of effective combinations has emerged as an interesting possibility in the food industry. In this study, the antimicrobial activities of essential oils (EOs) of cinnamon bark, cinnamon leaves, and clove and the pure compounds vanillin, eugenol, and cinnamaldehyde were investigated individually and in combination against Listeria monocytogenes and Escherichia coli O157:H7. The possible interactions of combinations of pure compounds and EOs were performed by the two-dimensional checkerboard assay and isobologram methods. Vanillin exhibited the lowest antimicrobial activity (MIC of 3002 ppm against L. monocytogenes and 2795 ppm against E. coli O157:H7), while clove and cinnamon bark EOs exhibited the highest antimicrobial activity (402–404 against L. monocytogenes and 778–721 against E. coli O157:H7). For L. monocytogenes, pure compound eugenol, the main component of cinnamon leaves and clove, showed lower antimicrobial activity than EOs, which was attributed to the influence of the minor components of the EOs. The same was observed with cinnamaldehyde, the main component of cinnamon bark EO. The combinations of vanillin/clove EO and vanillin/cinnamon bark EO showed the most synergistic antimicrobial effect. The combination of the EOs of cinnamon bark/clove and cinnamon bark/cinnamon leaves showed additive effect against L. monocytogenes but indifferent effect against E. coli O157:H7. For L. monocytogenes, the best inhibitory effects were achieved by cinnamon bark EO (85 ppm)/vanillin (910 ppm) and clove EO (121 ppm)/vanillin (691 ppm) combinations. For E. coli, the inhibitory effects of clove EO (104 ppm)/vanillin (1006 ppm) and cinnamon leaves EO (118 ppm)/vanillin (979 ppm) combinations were noteworthy. Some of the tested combinations increased the antimicrobial effect and would allow the effective doses to be reduced, thereby offering possible new applications for food and active food packaging.

scholarly journals Bacterial cellulose films with ZnO nanoparticles and propolis extracts: Synergistic antimicrobial effect

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Alexandra Mocanu ◽  
Gabriela Isopencu ◽  
Cristina Busuioc ◽  
Oana-Maria Popa ◽  
Paul Dietrich ◽  
...  
Keyword(s):  
Synergistic Effect ◽  
Bacterial Cellulose ◽  
Food Packaging ◽  
Antimicrobial Effect ◽  
Gas Chromatography Mass Spectrometry ◽  
Trolox Equivalent Antioxidant Capacity ◽  
Zno Nps ◽  
X Ray ◽  
Cellulose Films ◽  
Trolox Equivalent

AbstractThis study aimed to obtain possible materials for future antimicrobial food packaging applications based on biodegradable bacterial cellulose (BC). BC is a fermentation product obtained by Gluconacetobacter xylinum using food or agricultural wastes as substrate. In this work we investigated the synergistic effect of zinc oxide nanoparticles (ZnO NPs) and propolis extracts deposited on BC. ZnO NPs were generated in the presence of ultrasounds directly on the surface of BC films. The BC-ZnO composites were further impregnated with ethanolic propolis extracts (EEP) with different concentrations.The composition of raw propolis and EEP were previously determined by gas-chromatography mass-spectrometry (GC-MS), while the antioxidant activity was evaluated by TEAC (Trolox equivalent antioxidant capacity). The analysis methods performed on BC-ZnO composites such as scanning electron microscopy (SEM), thermo-gravimetrically analysis (TGA), and energy-dispersive X-ray spectroscopy (EDX) proved that ZnO NPs were formed and embedded in the whole structure of BC films. The BC-ZnO-propolis films were characterized by SEM and X-ray photon spectroscopy (XPS) in order to investigate the surface modifications. The antimicrobial synergistic effect of the BC-ZnO-propolis films were evaluated against Escherichia coli, Bacillus subtilis, and Candida albicans. The experimental results revealed that BC-ZnO had no influence on Gram-negative and eukaryotic cells.

Sol–gel method as a way of carbonyl iron powder surface modification for interaction improvement

2015 ◽  
Vol 226 ◽  
pp. 224-230 ◽  
Author(s):  
P. Małecki ◽  
K. Kolman ◽  
J. Pigłowski ◽  
J. Kaleta ◽  
J. Krzak
Keyword(s):  
Surface Modification ◽  
Iron Powder ◽  
Carbonyl Iron ◽  
Sol Gel ◽  
Powder Surface ◽  
Gel Method ◽  
Sol Gel Method ◽  
Carbonyl Iron Powder

Sol-gel processing of cordierite: Effect of seeding and optimization of heat treatment

1990 ◽  
Vol 5 (5) ◽  
pp. 1095-1103 ◽  
Author(s):  
Ann M. Kazakos ◽  
Sridhar Komarneni ◽  
Rustum Roy
Keyword(s):  
Heat Treatment ◽  
Single Phase ◽  
Excess Free Energy ◽  
Sol Gel ◽  
Nucleating Agents ◽  
Optimum Conditions ◽  
Nanosized Powders ◽  
Nanocomposite Gels ◽  
Powder Compacts ◽  
Gel Processing

Three series of cordierite powders were prepared by the sol-gel route: a single phase (monophasic) gel prepared from alkoxides, a nominally triphasic nanocomposite gel made with two nanosized powders and one solution phase, and a truly compositionally triphasic nanocomposite gel prepared from three nanosized powders. Crystalline α-cordierite seeds were also incorporated with the gels and their effectiveness as nucleating agents was investigated and found to lower the crystallization temperature of α-cordierite by 125–150°C. The densification behavior of powder compacts was examined and alterations made to the heat treatment until optimum conditions were found. The truly triphasic compact sintered at 1300°C for 2 h resulted in 100% of theoretical density whereas the nominally triphasic and monophasis pellets densified to 96% and 80%, respectively. The enhanced densification achieved with powder compacct prepared for triphasic nanocomposite gels is due to part to the excess free energy of the three components.

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