Preparation of VO2 Nanoparticles with Surface Functionalization for Thermochromic Application

Abstract

This recent work investigates on the modification of metal oxide particles surface by the addition of amorphous coating layer. This core-shell structure is expected to decrease particles aggregation and increase their distribution in polymer matrix. VO2 particles were firstly prepared via hydrothermal process with 87% yield and XRD analysis showed that VO2 monoclinic was obtained with 100% of purity. XPS technique also showed that the surface of VO2 particles contains -OH group which is promising to form the strong covalent bond with silane coupling agent. The addition of functional groups on the surface of VO2 particles was then performed by the grafting of (3-Aminopropyl) triethoxysilane (APTES) via the silane anchoring group with 1:10 weight ratio VO2/APTES. The effect of solvent was also studied by using 10 ml of different solvent such as distilled water, ethanol and chloroform during surface coating. The TEM image clearly shows the presence of the thick organic layer on VO2 particles and as a result, the core-shell structure was perfectly identified. The round shape of coated VO2 particles was detected with small aggregation by SEM imageries. Furthermore, the presence of characteristic absorption band of C-H, Si-O-C, Si-O-Si and NH stretching in the FTIR spectra of coated VO2 particles confirmed the existence of APTES on the surface of VO2 particles prepared in distilled water and ethanol.

Thermochromic and temperature regulation properties of phase change materials derived from polymer composites loaded with VO2 particles

“…Monoclinic phase VO 2 particles were prepared by hydrothermal and calcination techniques using V 2 O 5 and C 6 H 8 O 7 as a raw material and a reducing agent, respectively. More details concerning the synthesis procedures and the reaction conditions, can be seen in our previous report 31,32 . The monoclinic crystal structure of the synthesized VO 2 was verified by XRD technique, with respect to the JCPDS 440252 (see Figure S1).…”

“…More details concerning the synthesis procedures and the reaction conditions, can be seen in our previous report. 31,32 The monoclinic crystal structure of the synthesized VO 2 was verified by XRD technique, with respect to the JCPDS 440252 (see Figure S1). A critical transition temperature of VO 2 (m), determined by DSC technique, was 76.5 C (see also Figure S2).…”

Synthesis, Characterizations, and Thermochromic Properties of VO2 Particles Grafted with PSS : PEDOT

“…After that, the VO 2 particles were grafted with the silane coupling agent (APTES) to introduce amine functional groups onto the surface of VO 2 particles. Again, more details concerning this reaction step have been reported elsewhere [25]. Next, α-bromoisobutyryl bromide (BIBB), which served as an initiating species for ATRP, was anchored onto the VO 2 @APETS particles.…”

Synthesis and Deposition of Thermochromic VO2 Thin Films from Peroxide-based Chemical Solutions

“…To produce VO2 based coatings, two general approaches can be followed. The first method consists of the synthesis of preformed VO2(M) particles, followed by a deposition step in a suitable matrix [8][9][10][11][12][13]. According to both the Maxwell-Garnett effective-medium theory and the four-flux method, particle sizes should not exceed 20 nm to avoid scattering effects [14].…”