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Research Article
Fundamental Investigation of the Adsorption of Antimicrobial Agents on Modified Calcium Carbonate and Silica and Its Potential Application in Food Packaging
Abdul Haseeb,
Beko Mesic*,
Jörgen Samuelsson
Issue:
Volume 13, Issue 1, April 2024
Pages:
1-9
Received:
27 November 2023
Accepted:
21 December 2023
Published:
8 January 2024
Abstract: Antimicrobial packaging has emerged as one of the most effective packaging systems in prolonging shelf life and maintaining food quality. For an effective system, a controlled and gradual release of antimicrobial agents into food items over time is crucial. Modified Calcium Carbonate (MCC), known for its diverse applications in pharmaceuticals and drug delivery, could act as a potential carrier for such agents in packaging. In this context, a fundamental study of the adsorption of two reference antimicrobial agents, Benzoic Acid (BA) and Thymol (TM), was carried on MCC and silica in solvents of different polarities. Based on the initial adsorption study, the adsorption isotherms of the two compounds were acquired by batch method in different solvents and then the adsorption data was modeled using adsorption isotherm models. Here, we found that n-Heptane was the most efficient solvent for both BA and TM on both adsorbents. From the outcome of the adsorption study, a model dispersion coating was prepared by mixing MCC (loaded with BA) with latex binder. Then the effect of latex binder on the rate of BA release from MMC was investigated by conducting desorption study using simulated body fluid as the desorbent solution at 4°C, comparing MCC with and without latex. It was found that the release rate of BA from our latex model dispersion coating was 31 time slower than that of MMC without latex. This indicates the potential application of our model dispersion coating in antimicrobial packaging.
Abstract: Antimicrobial packaging has emerged as one of the most effective packaging systems in prolonging shelf life and maintaining food quality. For an effective system, a controlled and gradual release of antimicrobial agents into food items over time is crucial. Modified Calcium Carbonate (MCC), known for its diverse applications in pharmaceuticals and ...
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Research/Technical Note
The Influence of the Green Density on the Quality of ZTA Zirconia Toughened Alumina Plungers
Zlata Ibrisimovic Subasic*,
Minela Cejvan
Issue:
Volume 13, Issue 1, March 2024
Pages:
10-15
Received:
18 January 2024
Accepted:
2 February 2024
Published:
28 February 2024
Abstract: The purpose of this study is to investigate the effect of the green density (ρg) on the sintered density (ρs), shrinkage according height and diameter (HS, DS), relative density, porosity and hardness of ZTA ceramic plungers. Zirconia toughened alumina is characterized by excellent properties of hardness, toughness, thermal and chemical resistance, which make composite material interesting for multiple applications. Some of the significant applications of ZTA ceramics are in the production of biomedical implants, cutting tools, parts for pumps and others. The material is composed of high purity alumina 90% and 10% of zirconium oxide. This material successfully compensate fragility of the alumina and zirconium oxide price. After 24 hours of milling in a ball mill (Dorst, Germany) slurry with a specific surface 25 832 cm2/g was transferred into a mixer with addition of binders (PVA + soap based binder) through a vibrating sieve (British and Foreign Patents). Solid content (%) of the slurry in amount of 69.16 was confirmed by thermogravimetric and differential gravimetric analyzes. The 1000 kg of the powder dried by spray drying (Spray dryer Niro) contains 2.6% of binders and 0.2% of moisture. Three sets of plungers with outer diameter of 3.6 cm, inner diameter of 2.0 cm and height of 7.6 cm were produced by cold isostatic pressing (CIP) using different pressures. The first set marked as 'A' was pressed by pressure of 80 MPa, the second set marked as 'B' was pressed by pressure of 100 MPa, and third set marked as 'C', was pressed by pressure of 150 MPa. According to statistical data processing, comparison and analysis of the results it is concluded that the quality of the ZTA plungers, in specific presented case, significantly depends on the green density (ρg).
Abstract: The purpose of this study is to investigate the effect of the green density (ρg) on the sintered density (ρs), shrinkage according height and diameter (HS, DS), relative density, porosity and hardness of ZTA ceramic plungers. Zirconia toughened alumina is characterized by excellent properties of hardness, toughness, thermal and chemical resistance,...
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Communication
Electrical Resistivity Behavior and Small Polaron Conduction Transport Mechanism in Semiconducting RMnO3 Manganites
Ashwini Kumar,
Poorva Sharma*,
Qiu Fujun,
Hu Jiang,
Cui Jin
Issue:
Volume 13, Issue 1, March 2024
Pages:
16-19
Received:
21 January 2024
Accepted:
3 February 2024
Published:
28 February 2024
Abstract: Rare earth manganites, denoted by the chemical formula RMnO3, where R signifies a rare earth element, have garnered significant interest in recent years. These perovskite oxides exhibit intriguing phenomena such as multiferroicity, ferroelectricity, and colossal magnetoresistance, primarily attributed to the role of polarons in conduction. The incorporation of rare earth ions imparts flexibility, making these compounds promising for applications in spintronics, sensors, and information storage devices. This study delves into the electrical resistivity behavior and Small Polaron Conduction (SPC) mechanisms of rare earth manganites, particularly RMnO3. In this manuscript, electrical resistivity of the pristine RMnO3 (R = Sm, Eu, Gd) manganites are analyzed within the framework of adiabatic nearest-neighbor hopping of SPC. The high temperature state of RMnO3 within the SPC mechanism is influenced by polaron concentration, hopping distance, and resistivity coefficient. The localized charge carriers in undoped manganites enable one to estimate the activation energy for the electrical conduction. The activation energy decreases with the decrease in ionic radii from Sm to Gd. Deduced polaron activation energy is low for GdMnO3 as compared to SmMnO3 and is attributed to reducing disorder state in GdMnO3 as compared to SmMnO3. This work contributes to the fundamental understanding of condensed matter physics and the potential applications of rare earth manganites in emerging technologies. The interplay between electrical resistivity and Small Polaron Conduction offers insights for customizing these materials for specific technological needs.
Abstract: Rare earth manganites, denoted by the chemical formula RMnO3, where R signifies a rare earth element, have garnered significant interest in recent years. These perovskite oxides exhibit intriguing phenomena such as multiferroicity, ferroelectricity, and colossal magnetoresistance, primarily attributed to the role of polarons in conduction. The inco...
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