Morphology and Thermal Properties of Calcium Alginate/Reduced Graphene Oxide Composites

Abstract

Calcium alginate (CaAlg) is a kind of biodegradable and eco-friendly functional material, and CaAlg/reduced graphene oxide (rGO) composites are expected to be applied as new textile, heat-generating, and flame-retardant materials. In this paper, the CaAlg/rGO composites were prepared by a sol-gel method and their morphological and thermal properties were studied. The results showed that the introduction of rGO can efficiently improve the thermal stability of CaAlg. Further study showed that rGO increased the carbon formation rate by 4.1%, indicating that the thermal stability was improved by the promotion of carbon formation. Moreover, the weight loss rate of the composites was faster at 180–200 °C than that of CaAlg, after which the rate was less comparatively, suggesting the better thermal stability of the composite. This maybe because the high heat transfer efficiency of rGO allowed the material to reach the temperature of the thermal decomposition of the glycan molecule chain within a short time, and then promoted carbon formation. The thermal cracking mechanism of the composites is proposed based on the experimental data.

Microencapsulated Bio-Based Rejuvenators for the Self-Healing of Bituminous Materials

“…The first peak around 185 °C is associated with dehydration reactions in the alginate; while the second one, at 278 °C, corresponds to the degradation of the CaCO3. Likewise, the weight loss below 300 °C is caused by the loss of hydroxyl groups (-OH) in the alginate, and above this temperature decarboxylation reactions take place forming CO2 as the main product [29]. When BO is confined into the CaAlg capsules (BO Cap_2% and BO Cap_3%) the TGA Likewise, the weight loss below 300 • C is caused by the loss of hydroxyl groups (-OH) in the alginate, and above this temperature decarboxylation reactions take place forming CO 2 as the main product [29].…”

“…Likewise, the weight loss below 300 °C is caused by the loss of hydroxyl groups (-OH) in the alginate, and above this temperature decarboxylation reactions take place forming CO2 as the main product [29]. When BO is confined into the CaAlg capsules (BO Cap_2% and BO Cap_3%) the TGA Likewise, the weight loss below 300 • C is caused by the loss of hydroxyl groups (-OH) in the alginate, and above this temperature decarboxylation reactions take place forming CO 2 as the main product [29]. When BO is confined into the CaAlg capsules (BO Cap_2% and BO Cap_3%) the TGA profiles of the BioPoly and that of the capsules containing the BO are very similar until 175 • C. Above 175 • C, the decomposition of the BO starts showing a DTG shoulder at Tsh = 190 • C, which could be attributed to the breakage of C-H and C-O-H in lighter molecules, such as carboxylic acids, and, to some extent, to the decomposition of the alginate itself.…”

Antimicrobial functionalization of Ca alginate‐coconut oil latent heat storing microcapsules by Ag nanoparticles

“…This oxidative degradation/burning step is also confirmed by series of overlapped exothermic peaks. 44,45 The small mass loss step above 668.39 C (Δm −1.2%) corresponds to the degradation of the calcium carbonate, which was formed previously during the oxidative degradations of the calcium alginate. From thermal point of view, coconut oil is a little bit more stable, compared to the calcium alginate.…”

Graphene Modified Multifunctional Personal Protective Clothing

“…Zhao et al reported preparation of graphene modified calcium alginate composite using sol–gel process. The composite showed improved thermal stability and increased carbon formation, thus showed notable promise as multifunctional smart textiles having good fire retardancy and heat generating ability …”