Effects of nanosilica on retrogradation properties and structures of thermoplastic cassava starch

Abstract

Composites of thermoplastic cassava starch (TPS) and nanosilica (SiO 2 ) were prepared by the melting method. The effect of nano-SiO 2 on the retrogradation properties and structures of cassava starch was investigated. The retrogradation degree of TPS/ nano-SiO 2 composites increased with increasing retrogradation time. The retrogradation rate of TPS significantly increased after the addition of nano-SiO 2 , but excessive nano-SiO 2 content leads to a decrease in the retrogradation rate of TPS. According to the Fourier transform infrared spectroscopy results, the retrogradation degree of TPS/nano-SiO 2 composites increased with the increase of retrogradation time and addition of nano-SiO 2 . Scanning electron microscopy analysis indicated that nano-SiO 2 particles were uniformly and finely dispersed in the starch materials, but the nano-SiO 2 particles aggregated in the cassava starch with a further increase in nano-SiO 2 content. X-ray diffraction revealed that the crystalline structure of the starch was gradually altered from A-type to Vtype with the increase of retrogradation time. TPS/SiO 2 composites indicated a mixture of A1V types, and the intensity of the Vtype strengthened with the increase of retrogradation time and SiO 2 content. Polarized light microscopy analysis revealed clear Maltese cross patterns, and the number of spherulites in TPS/nano-SiO 2 composites increased with increasing retrogradation time and nano-SiO 2 content, but the retrogradation of starch was inhibited with further increases of nano-SiO 2 content.

Effects of high hydrostatic pressure on structures, properties of starch, and quality of cationic starch

“…Starch is a kind of polyhydroxy compound (Liu, Fan, Mo, Yang, & Pang, 2017). In starch granules, the outmost spherical blocklets are closely arranged to form the shells of granules which prevent the denaturant from entering the starch granules.…”

Preparation of octenyl succinic anhydride‐modified cassava starch by the ultrasonic‐assisted method and its influence mechanism

“…Among them, D50 represents the average particle size. The standard mean diameters include plane mean diameter D(3,2) and volume mean diameter D(4,3) (Liu, Fan, Mo, Yang, & Pang, ).…”

“…In Figure a, arrow 1 refers to the "growth rings" and arrow 2 refers to "pores and central cavity structures." In Figure C, the arrows refer to "bulges"diameter D(3,2) and volume mean diameter D(4,3)(Liu, Fan, Mo, Yang, & Pang, 2017).…”

Thermoplastic Starch Composites With Titanium Dioxide and Vancomycin Antibiotic: Preparation, Morphology, Thermomechanical Properties, and Antimicrobial Susceptibility Testing

“…This work is focused on TPS composites with titanium dioxide, with high content of filler (>10 wt.%), which have not been studied so far according to available literature, as summarized below. Common fillers employed in TPS composites comprise clays (Carvahlo et al, 2001;Dai et al, 2012;Kelnar et al, 2013;Oleyaei et al, 2016a;Campos-Requena et al, 2017;Olivato et al, 2017), graphene (Javanbakht and Namazi, 2017), carbon nanotubes (CNT) (Liu S. et al, 2017), natural fibers (Svagan et al, 2009;Kargarzadeh et al, 2017;Pelissari et al, 2017;Ilyas et al, 2018Ilyas et al, , 2019, polysaccharidebased crystals (Dufresne and Castano, 2017;Ali et al, 2018), and metal oxides and chalcogenides (Oleyaei et al, 2016b;Guz et al, 2017;Liu et al, 2018). Titanium dioxide (TiO 2 ) represents attractive filler in materials for biomedical applications due to its biocompatibility with bone cells and tissues (Webster et al, 1999(Webster et al, , 2000Sengottuvelan et al, 2017).…”