Ultra‐microstructural features of perborate oxidized starch

Hebeish, A.; El‐Rafie, M. H.; Rabie, Ahmed; El-Sheikh, Manal A.; El‐Naggar, Mehrez E.

doi:10.1002/app.40170

Cited by 38 publications

(24 citation statements)

References 48 publications

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“…To reduce life cycle impacts due to the chemical reducing agents, plant extracts can be used as an bio-based alternative. With~100% yield, 44 90 kg of starch is required alongside 1000 liter of water to reduce 1.57 kg of silver nitrate to produce 1 kg of silver nanoparticles. 29 Here, 0.9 g of a chemically modified starch (hydroxypropyl starch, with molar substitution ratio of 0.84, resulting in its complete solubility in water) is added to 100 ml deionized water and heated up to 70°C.…”

Section: Agnp Synthesis Routesmentioning

confidence: 99%

Comparative life cycle assessment of silver nanoparticle synthesis routes

Pourzahedi

Eckelman

2015

Environ. Sci.: Nano

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Silver nanoparticles (AgNPs) can be produced through a variety of synthesis routes with differing mechanisms, inputs, yields, reaction conditions, and resulting size distributions. Recent work has focused on applying green chemistry and sustainable manufacturing principles to nanomaterial synthesis, with the goal of reducing life cycle energy use and environmental impacts. Life cycle assessment (LCA) is used here to analyze and compare the environmental impacts of AgNPs produced through seven different synthesis routes (cradle-to-gate). LCA reveals both direct and indirect or upstream impacts associated with AgNPs.Synthesis routes were chosen to represent current trends in nanoparticle synthesis and include physical, chemical and bio-based methods of production. Results show that, across synthesis routes, impacts associated with the upstream production of bulk silver itself were dominant for nearly every category of environmental impact, contributing to over 90% of life cycle burdens in some cases. Flame spray methods were shown to have the highest impacts while chemical reduction methods were generally preferred when AgNPs were compared on a mass basis. The bio-based chemical reduction route was found to have important tradeoffs in ozone depletion potential and ecotoxicity. Rescaling results by the size-dependent antimicrobial efficacy that reflects the actual function of AgNPs in most products provided a performancebased comparison and changed the rank order of preference in every impact category. Comparative results were also presented in the context of a nanosilver-doped wound dressing, showing that the overall environmental burdens of the product were highly sensitive to the synthesis route by which the AgNPs are produced.Environ. Sci.: Nano This journal is † Electronic supplementary information (ESI) available. See Nanoparticle synthesis has been found in several life cycle assessments (LCAs) of AgNP-containing products to be a large contributor of environmental impacts. Impacts are highly dependent on the synthesis route, yet several routes lack LCA data and/or results. Here we conduct and compare LCAs for all industrially important synthesis routes and identify critical inputs and synthesis steps, informing future process improvements. Impacts from the production of bulk silver were dominant for nearly every impact category, but with different patterns among routes. Results are presented on a mass basis as well as by antimicrobial efficiency, a novel approach. This work provides a transparent and general basis for the research community to model nano life cycle impacts in subsequent assessments of AgNP-enabled products.

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Section: Agnp Synthesis Routesmentioning

confidence: 99%

Comparative life cycle assessment of silver nanoparticle synthesis routes

Pourzahedi

Eckelman

2015

Environ. Sci.: Nano

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“…The acidic (carboxyl) [17] and reducing (carbonyl) groups of Galactomannan fenugreek gum before and after oxidation with SPB was determined according to a method of Wing and Willett [17][18][19].…”

Section: Characterization Of the Oxidized Galactomannan Fenugreek Gummentioning

confidence: 99%

“…The rheological properties and apparent viscosity were carried out using Brookfield model DV-111, Programmable Rheometer, U.S.A. at different rates of shear range between, 3.4 -68 s-1, at 25°C according to a procedure reported elsewhere [19] by dissolving the purified samples in tap water at a concentration of 3%. The apparent viscosity was calculated using the following formula: Where = apparent viscosity in poise.…”

Section: Rheological Measurementmentioning

confidence: 99%

“…Thermal characterizations and the remaining ash content were evaluated using a TA Instruments TGA Q5000 at a heating rate of 10 K/min under air atmosphere. High temperature platinum pans were used and sample mass was approximately 5 mg. Color strength expressed as K/S was measured by a previously reported method [19] by the light reflectance technique.…”

Section: = Rate Of Shear (S -1 )mentioning

confidence: 99%

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Microstructural features of Galactomannan Fenugreek gum newly oxidized by sodium perborate under microwave irradiation for reactive printing

et al. 2019

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G ALACTOMANNAN gum was extracted from fenugreek seeds through seed grinding and sifting, washing and filtering and precipitating by ethyl alcohol and drying. Thus obtained products were submitted to innovative oxidation using microwave irradiation and sodium perborate (SPB) oxidant under a variety of conditions. Variable studied include concentration of SPB and duration of oxidation as well as pH and temperature of the oxidation reaction. Thus oxidized gum samples were subjected to chemical and chemical-microscopically analysis for quantitative determination of carboxyl and carbonyl groups and rheological properties along wilts residual SPB. Microstructural changes in the innovatively oxidized gum vis-à-vis those of conventionally oxidized gum were presented. Results indicate that the innovative oxidation using the microwave for heating the oxidation medium containing SPB consumes less time and energy than the conventional oxidation by SPB using conventional heating. Results indicate further that current oxidation using the microwave or conventional heating brings into focus oxidized galactomannan gums, which induce excellent overall color fastness when applied as thickeners in printing pastes of reactive dyes. These gums may be considered as a real substitute for sodium alginate thickener which is universally accepted thickeners for reactive printing on cotton. In addition, oxidized galactomannan gum creates eco-friendly environment during its preparation.

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“…In practice, SPB is not only cost effective but also presents distinctive benefits such as being available as a solid form of hydrogen peroxide [13]. However, SPB has proven to be a better alternative to hydrogen peroxide since the former has not only provided superior stability at higher temperatures but also proven to be an efficient source of per hydroxyl anions, superoxide and active oxygen [14].…”

Section: Introductionmentioning

confidence: 99%

Improved Thermal Processing of Polylactic Acid/Oxidized Starch Composites and Flame-Retardant Behavior of Intumescent Non-Wovens

Maqsood

Seide

2020

Coatings

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Thermoplastic processing and spinning of native starch is very challenging due to (a) the linear and branched polymers (amylose and amylopectin) present in its structure and (b) the presence of inter-and-intramolecular hydrogen bond linkages in its macromolecules that restrict the molecular chain mobility. Therefore, in this study, oxidized starch (OS) (obtained after oxidation of native starch with sodium perborate) was melt-blended with polylactic acid (PLA) polymer to prepare PLA/OS blends that were then mixed together with ammonium polyphosphate (APP), a halogen-free flame retardant (FR) used as acid donor in intumescent formulations on twin-screw extruder to prepare PLA/OS/APP composites. OS with different concentrations also served as bio-based carbonic source in intumescent formulations. PLA/OS/APP composites were melt spun to multifilament fibers on pilot scale melt-spinning machine and their crystallinity and mechanical properties were optimized by varying spinning parameters. The crystallinity of the fibers was studied by differential scanning calorimetry and thermal stabilities were analyzed by thermogravimetric analysis. Scanning electron microscopy was used to investigate the surface morphology and dispersion of the additives in the fibers. Needle-punched non-woven fabrics from as prepared melt-spun PLA/OS/APP fibers were developed and their fire properties such as heat release rate, total heat release, time to ignition, residual mass % etc. by cone calorimetry test were measured. It was found that PLA/OS/APP composites can be melt spun to multifilament fibers and non-woven flame-retardant fabrics produced thereof can be used in industrial FR applications.

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Ultra‐microstructural features of perborate oxidized starch

Cited by 38 publications

References 48 publications

Comparative life cycle assessment of silver nanoparticle synthesis routes

Comparative life cycle assessment of silver nanoparticle synthesis routes

Microstructural features of Galactomannan Fenugreek gum newly oxidized by sodium perborate under microwave irradiation for reactive printing

Improved Thermal Processing of Polylactic Acid/Oxidized Starch Composites and Flame-Retardant Behavior of Intumescent Non-Wovens

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