Use of new silica fillers as additives for polymers used in packaging of fruit

Abstract

Recebido em 25/10/11; aceito em 18/6/12; publicado na web em 28/9/12The objective of this work was to synthesize nanosilicas with different degree of hydrophobicity by the sol-gel method, using tetraethyl orthosilicate as a precursor. For this purpose, 3-aminopropyl triethoxysilane (APS) and 1,1,1,3,3,3-hexamethyldisilazane (HMDS), were added during synthesis as modifiers. A commercial biopolymer (Hexamoll Dinch, BASF) intended for packaging of apples, was added to the new nanosilicas. The materials obtained were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, potentiometric titration, porosity, specific surface area and hydrophobicity/ hydrophilicity by wetting test. Colorimetry was used to evaluate change in apple pulp color after contact with the different silicas.

Antifungal activity of cotton fabrics finished modified silica-silver- carbon-based hybrid nanoparticles

“…This result was also observed by our group in previous studies. 31,32,[38][39][40] There are no large variations in the bands; small shoulders in the region between 1750 and 1250 cm -1 can be associated with the methyl groups belonging to the APTES (Figure 3(b)). Fourier transform infrared spectrum of the synthesized samples: (a) pure silica (KHA), silica with 0.1%(w/w) of carbon (K1HA), silica with 1.0% (w/w) of carbon (K2HA), silica with 10.0% (w/w) of carbon (K3HA) and (b) pure silica functionalized with 3aminopropyltriethoxysilane in 1:1 molar ratio (KHAf), silica with 0.1%(w/w) of carbon and functionalized with 3-aminopropyltriethoxysilane in 1:1 molar ratio (K1HAf), silica with 1.0%(w/w) of carbon and functionalized with 3-aminopropyltriethoxysilane in 1:1 molar ratio (K2HAf), silica with 10.0%(w/w) of carbon and functionalized with 3-aminopropyltriethoxysilane in 1:1 molar ratio (K3HAf).…”

The Effect of Silica and Prepolymer Nanoparticles on the Mechanical Properties of Denture Base Acrylic Resin

“…There are some advantages of denture base acrylic resin such as biocompatibility and esthetics . In addition, it is easy to process, does not cost much and it possesses certain qualities such as low weight, and low water sorption and solubility levels . However, it has been noted that acrylic dentures could crack due to fatigue or the shock imparted by mastication, making the acrylic resin hard to repair …”

Effects of the Addition of Titanium Dioxide and Silaned Silica Nanoparticles on the Mechanical Properties of Maxillofacial Silicones

“…Defects to the face that occur due to trauma, congenital malformation, or carcinoma are called maxillofacial defects . Maxillofacial prosthetics are used to help with the functional and the esthetic restoration of the congenital, acquired, or developmental defects of the head and the neck area . Maxillofacial prosthetics is still a necessity for cancer and trauma patients, despite new developments in plastic surgery …”