Development of facture free clay-based aerogel: Formulation and architectural mechanisms

Clay aerogel could potentially be ideal insulation materials for many industrial sectors because of its natural resource, green and low cost production. However, there is a dilemma between thermal conductivity and integrity, which are also highly related to density and microstructure. These could be manipulated through formulation compositions and processing parameters. This paper employs cellulose nanowhisker (CNW) as the reinforcement to develop novel 3-component systems of aerogel by exploring optimum formulation and architectural microstructure systems. The results shows that fracture free clay aerogel can be developed with solid content less than 4wt%, enabling optimum thermal insulation performance of 0.034 W/mK; optimum micro-network and hence much more enhanced bonding systems can be built with strategical interactions within and between clay platelets, PVA and CNW; and an architecture of ‘CNW-clay (mechanically)+CNW-PVA (chemically)+CNW-clay’ 3-component clay aerogels could be established, achieving excellent mechanical property (e.g. compressive strength and shape recovery)

Structure and mechanical properties of sodium and calcium caseinate edible active films with carvacrol

Edible active films based on sodium caseinate (SC) and calcium caseinate (CC) plasticized with glycerol (G) at three different concentrations and carvacrol (CRV) as active agent were prepared by solvent casting. Transparent films were obtained and their surfaces were analysed by optical microscopy and scanning electron microscopy (SEM). The influence of the addition of three different plasticizer concentrations was studied by determining tensile properties, while Fourier transformed infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA) were used to evaluate the structural and thermal behavior of such films. The addition of glycerol resulted in a reduction in the elastic modulus and tensile strength, while some increase in the elongation at break was observed. In general terms, SC films showed flexibility higher than the corresponding CC counterparts. In addition, the presence of carvacrol caused further improvements in ductile properties suggesting the presence of stronger interactions between the protein matrix and glycerol, as it was also observed in thermal degradation studies. FTIR spectra of all films showed the characteristic bands and peaks corresponding to proteins as well as to primary and secondary alcohols. In summary, the best results regarding mechanical and structural properties for caseinates-based films containing carvacrol were found for the formulations with high glycerol concentrations.Marina Patricia Arrieta thanks Fundacion MAPFRE for "Ignacio Hernando de Larramendi 2009- Medio Ambiente" fellowship (MAPFRE-IHL-01). The Spanish Ministry of Economy and Competitiveness is acknowledged by financial support (project Ref. MAT2011-28468-C02-01). Authors thank to Ferrer Alimentacion S.A., for providing caseinates and to Prof. Juan Lopez Martinez (Polytechnic University of Valencia, Spain) for his collaboration and useful discussions.Arrieta, MP.; Peltzer, MA.; Garrigós, MDC.; Jimenez, A. (2013). Structure and mechanical properties of sodium and calcium caseinate edible active films with carvacrol. Journal of Food Engineering. 114(4):486-494. https://doi.org/10.1016/j.jfoodeng.2012.09.002S486494114