Design and preparation of poly(vinyl alcohol) flexible nanocomposite films containing silica nanoparticles with citric acid and ascorbic acid linkages as a novel nanofiller through a green route

Abstract

To prevent SiO 2 nanoparticle (SNP)s from aggregation, surface modification of them was performed using bio-safe citric acid (CA) and L(+)-ascorbic acid (vit C) for the first time.After that, NC films of well dispersed Modified SiO 2 (Mod-SiO 2 ) in the poly(vinyl alcohol) (PVA) matrix (PVA/Mod-SiO 2 ) were prepared using solution casting method.The prepared NC films loaded with different mass fractions (4, 8 and 12 wt%) of Mod-SiO 2 were analyzed by several techniques. Field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM) showed that Mod-SiO 2 with size ranging between 23-27 nm is dispersed in the PVA matrix . With Thermogravimetric analysis (TGA) the amount of attached modifiers was estimated 13 wt%. TGA results also indicated that the incorporation of Mod-SiO 2 in the PVA matrix can improve its thermal stability.

Partially Neutralized Polyacrylic Acid/Poly(vinyl alcohol) Blends as Effective Binders for High-Performance Silicon Anodes in Lithium-Ion Batteries

“…26 After it has been crossed-linked with PVA, the OH band (hydroxyl group) is decreased and is shifted to a higher region. Moreover, the CO stretching band, which is attributed to the carboxylic acid group from PAA, 22 is significantly reduced. This indicates the formation of  COO caused by the esterification reaction of PAA and PVA.…”

“…21 For copolymers such as PAA/PVA, which normally require acidic condition for crosslinking, partial neutralization of PAA (5−10%) could also facilitate forming a stronger interconnection between different functional groups. 22…”

“…This is a result from partial neutralization of PAA in the blends, which has been approved to be able to improve the cross-link degree between PAA and PVA. 22 Figure 5 shows that the absorbance of the OH stretching band in PAA is a variable double peak between 3000 and 3460 cm −1 and overlaps with the CH stretching band at 2920 cm −1 . 26 After it has been crossed-linked with PVA, the OH band (hydroxyl group) is decreased and is shifted to a higher region.…”

The synthesis of poly(vinyl chloride) nanocomposite films containing ZrO2 nanoparticles modified with vitamin B1 with the aim of improving the mechanical, thermal and optical properties

“…Also, Van der Waals forces between ZrO 2 –VB 1 NPs surface and PVC segments can be responsible for the overall adsorption process [ 4 ]. Ultrasonic irradiation can help better dispersion of NPs in the PVC matrix [ 16 ].…”

“…The band around about 750 cm −1 was attributed to the Zr–O stretching vibration and a band at 1435 cm −1 was correspond to the bending vibration of Zr–OH [ 20 ]. In the FT-IR spectrum of VB 1 (Figure 2 (c)) a broad band in the region of 2500–3500 cm −1 was corresponded to the powerful inter- and intramolecular hydrogen bonding in the VB 1 [ 16 ]. The bands at 3423 and 3185 cm −1 were assigned to the –NH and –NH 2 stretching bands and the band at 3493 cm −1 is related to O–H stretching vibration band.…”