Relative permittivity and electrical conductivity of some divalent metal alginate complexes

Wahab, Sameh Mohamed Abdel; Ahmed, M. A.; Radwan, F.A.; Hassan, Refat M.; El-Refae, A.M.

doi:10.1016/s0167-577x(96)00196-6

Cited by 21 publications

(7 citation statements)

References 15 publications

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“…Alginate gels upon contact with divalent metals (e.g. calcium, cadmium or zinc [56]), forming what has been described as an "egg box structure" between four G residues ( Figure 6) [57]. This ability has been exploited to form microcapsules using an extrusion process ( Figure).…”

Section: Figure 5: Structural Intricacies Of Alginatementioning

confidence: 99%

Microencapsulation of probiotics for gastrointestinal delivery

Cook

Tzortzis

Charalampopoulos

et al. 2012

Journal of Controlled Release

593

354

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The administration of probiotic bacteria as nutraceuticals is an area that has rapidly expanded in recent years, with a global market worth $32.6 billion predicted by 2014. Many of the health promoting claims attributed to these bacteria are dependent on the cells being both viable and sufficiently numerous in the intestinal tract. The oral administration of most bacteria results in a large loss of viability associated with passage through the stomach, which is attributed to the high acid and bile salt concentrations present. This loss of viability effectively lowers the efficacy of the administered supplement. The formulation of these probiotics into microcapsules is an emerging method to reduce cell death during GI passage, as well as an opportunity to control release of these cells across the intestinal tract. The majority of this technology is based on the immobilization of bacteria into a polymer matrix, which retains its structure in the stomach before degrading and dissolving in the intestine, unlike the diffusion based unloading of most controlled release devices for small molecules. This review shall provide an overview of progress in this field as well as draw attention to areas where studies have fallen short. This will be followed by a discussion of emerging trends in the field, highlighting key areas in which further research is necessary.

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Section: Figure 5: Structural Intricacies Of Alginatementioning

confidence: 99%

Microencapsulation of probiotics for gastrointestinal delivery

Cook

Tzortzis

Charalampopoulos

et al. 2012

Journal of Controlled Release

593

354

View full text Add to dashboard Cite

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“…Gels of synthetic origin and to a lesser extent natural contracted networks were the objects of such studies (3). Fewer reports have dealt with natural polysaccharide gels under electrical field applications (4, 5). In a different scientific field, food preservation with pulsed electrical fields (PEF) was developed.…”

Section: Introductionmentioning

confidence: 99%

Direct Current Electrical Field Effects on Intact Plant Organs

et al. 2003

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Intact plant tissues (of hypocotyls, radicles, cotyledons and leaves) were contracted by applying a low DC electrical field through them. Stomatal opening as a result of the electrical treatment of leaves was observed, presumably due to the differential influence of the electrical treatment on guard cell turgor pressure versus turgor pressure of the surrounding epidermal cells. In addition, leakage of minerals from the treated leaves was detected (higher contents of potassium, sodium, calcium and sulfur), as was leakage of betanin from electrically treated red beet roots (higher OD value of the immersion solution with increasing time of applied electrical field). Application of such a treatment can be used for initial drying or as part of another more drastic drying method. The advantages of this method lie in its nonthermal character and its potential to increase the quality of processed foods by maintaining their "like-fresh" quality, e.g., fruits and vegetables that are less damaged by browning. An understanding of the mechanism involved in this nonthermal application can help in controlling the process and predicting its outcome.

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“…This leads to a decrease in the ε′ and ε″ values. Such a mechanism is termed anomalous dielectric dispersion ( Wahab et al, 1997 ; Reddy et al, 2010 ; Praveena et al, 2014 ; Abbas et al, 2015 ).…”

Section: Resultsmentioning

confidence: 99%

Preparation, Characterization and Dielectric Properties of Alginate-Based Composite Films Containing Lithium Silver Oxide Nanoparticles

et al. 2022

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Polymer composites have found applications in diverse areas, ranging from the manufacturing of portable electronic devices to the fabrication of bioactive agent carriers. This article reports the preparation of composite films consisting of sodium alginate (SA) and lithium silver oxide (LAO) nanoparticles. The films are generated by solution casting; whereas the nanoparticles are fabricated by using the hydrothermal method. The effects of the nanoparticles on the morphological, thermal, and dielectric properties of the films are examined by using Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD) analysis, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and scanning electron microscopy (SEM). Electrical measurements are also performed to determine the dielectric constant (ε′), dielectric loss (ε″), AC conductivity (σac), electrical moduli (M′ and M″), and impedance (Z' and Z″). The composite films are shown to be crystalline in nature, with nanoparticles having a diameter of 30–45 nm effectively disseminated in the polymer matrix. They also display good dielectric properties. Our results suggest that the films warrant further exploration for possible use in microelectronic applications.

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Relative permittivity and electrical conductivity of some divalent metal alginate complexes

Cited by 21 publications

References 15 publications

Microencapsulation of probiotics for gastrointestinal delivery

Microencapsulation of probiotics for gastrointestinal delivery

Direct Current Electrical Field Effects on Intact Plant Organs

Preparation, Characterization and Dielectric Properties of Alginate-Based Composite Films Containing Lithium Silver Oxide Nanoparticles

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