Nanocomposite-forming solutions based on cassava starch and laponite: Viscoelastic and rheological characterization

Abstract

a b s t r a c tNanocomposites-forming solutions (NFS) based on cassava starch and laponite were prepared and next characterized by means of dynamic oscillatory and steady shear rheological tests to evaluate their ability to be processed by knife coating. The effects of speed (rpm) and homogenization time on the laponite dispersion characteristics were first analyzed. Laponite dispersions were affected by both process parameters. High speed (rpm), i.e. 20,000 or 23,000 rpm for 30 min or prolonged homogenization time (10,000 rpm 6 speed agitation 6 23,000 rpm, for 60 min) led to high f-potential values, with laponite particles size <80 nm. With addition of laponite nanoparticles to cassava starch dispersion, an evident transition in NFS from liquid-like viscous to solid-like elastic behavior was observed. Rheological results indicated that laponite nanoparticles induced new interactions with starch chains allowing to obtain a network structure typical of a semi-rigid gel which shows some spread ability.

Physicochemical and rheo-mechanical properties of titanium dioxide reinforced sage seed gum nanohybrid hydrogel

“…obtained results illustrated a structural modification of the nanocomposites with the TiO2 load [46].…”

Mathematical Models for Prediction of Water Evaporation and Thermal Degradation Kinetics of Potato Starch Nanoparticles Obtained by Nanoprecipitation

“…First, PS granules were dispersed in a solution previously prepared of sodium hydroxide (1.5% w/w) in deionized water. Then, PS dispersions were heated at 363 ± 1 K for 30 min under constant agitation (1050 rpm), to promote starch gelatinization . In sequence, three drops of absolute ethanol were added to the gelatinized PS solution to a proportion 1:1 (% v/v).…”

“…The resulting solution was disposed to agitation at 298 K for 6 h under constant agitation. All solutions were covered with a preservative film to minimize the loss of moisture during heating and cooling …”

“…SNPs can improve mechanical, barrier, and chemical grafting properties in polymeric materials . The improvement of physicochemical properties of materials when they are charged with nanoparticles is due to atomic and molecular interactions of nanoparticles which have a significant influence on the macroscopic properties of materials …”

Propriedades de soluções filmogênicas e de filmes de gelatina ou colágeno com extrato de boldo-do-Chile

“…resfriamento, e TGEL-SOL, no aquecimento foram obtidas como a partir da primeira derivada do módulo de armazenamento em função da temperatura (JORGE et al 2014;MORAES et al, 2009;PERESSINI et al, 2003 (MORAES et al, 2009;PERESSINI et al, 2003). O intervalo de taxa de deformação escolhido variou de 0 a 200s -1 , e as amostras foram submetidas a três rampas de taxa de deformação, sendo estas: crescente, decrescente e crescente, com duração de dois minutos cada (JORGE et al, 2014;VALENCIA et al, 2015). A resposta obtida das curvas de fluxo para as SF foi a viscosidade (µ, mPa.s), isso porque estas se tratarem de fluidos Newtoniano.…”