Synthesis, characterization and optical properties of polymer‐based ZnS nanocomposites

Abstract

Nanostructured polymer-semiconductor hybrid materials such as ZnS-poly(vinyl alcohol) (ZnS-PVA), ZnS-starch and ZnS-hydroxypropylmethyl cellulose (Zns-HPMC) are synthesized by a facile aqueous route. The obtained nanocomposites are characterized using various techniques such as X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), UV/vis spectroscopy and photoluminescence (PL). XRD studies confirm the zinc blende phase of the nanocomposites and indicate the high purity of the samples. SEM studies indicate small nanoparticles clinging to the surface of a bigger particle. The Energy Dispersive Analysis by X-rays (EDAX) spectrum reveals that the elemental composition of the nanocomposites consists primarily of Zn:S. FTIR studies indicate that the polymer matrix is closely associated with ZnS nanoparticles. The large number of hydroxyl groups in the polymer matrix facilitates the complexation of metal ions. The absorption spectra of the specimens show a blue shift in the absorption edge. The spectrum reveals an absorption edge at 320, 310 and 325 nm, respectively. PL of nanocomposites shows broad peaks in the violet-blue region (420-450 nm). The emission intensity changes with the nature of capping agent. The PL intensity of ZnS-HPMC nanocomposites is found to be highest among the studied nanocomposites. The results clearly indicate that hydroxyl-functionalized HPMC is much more effective at nucleating and stabilizing colloidal ZnS nanoparticles in aqueous suspensions compared with PVA and starch.

Synthesis, characterization, and debromination reactivity of cellulose-stabilized Pd/Fe nanoparticles for 2,2',4,4'-tretrabromodiphenyl ether

“…By comparing the spectra of the free HPMC with HPMC-Pd/Fe NPs, the band corresponding to -OH stretching shifted from 3447.8 to 3373.4 cm -1 , suggesting that -OH group of HPMC is successfully involved in forming hydrogen bond with the particle surfaces. This observation is in good agreement with the previous studies obtained by Tiwari et al [33] and Maity et al [34]. …”

“…In the case of HPMC-Pd/Fe NPs (Fig 5(B)), it could be seen that there are vibration peaks corresponding to -OH groups (3420.3 cm -1 ), C-O stretching (1021.8 cm -1 ), and -CH 3 deformation vibrations (1408.9 cm -1 ) [33, 34]. By comparing the spectra of the free HPMC with HPMC-Pd/Fe NPs, the band corresponding to -OH stretching shifted from 3447.8 to 3373.4 cm -1 , suggesting that -OH group of HPMC is successfully involved in forming hydrogen bond with the particle surfaces.…”

“…To the best of our knowledge, there are no related reports using PAC as a nanoparticle stabilizer. In addition, hydroxypropylmethyl cellulose (HPMC) bearing a large amount of hydroxyl groups is also an important chemical cellulose derivative [33, 34]. Tiwari et al [33] found that HPMC was much more effective at nucleating and stabilizing colloidal ZnS nanoparticles in aqueous suspensions compared with poly(vinyl alcohol) (PVA) and starch.…”

“…In addition, hydroxypropylmethyl cellulose (HPMC) bearing a large amount of hydroxyl groups is also an important chemical cellulose derivative [33, 34]. Tiwari et al [33] found that HPMC was much more effective at nucleating and stabilizing colloidal ZnS nanoparticles in aqueous suspensions compared with poly(vinyl alcohol) (PVA) and starch. However, up to date, the available data about stabilization mechanism and enhanced degradation reactivity on contaminations by HPMC stabilized Pd/Fe NPs is still scarce.…”

Stabilization of ZnS nanoparticles by polymeric matrices: syntheses, optical properties and recent applications

“…The chemical structure of the polymeric ligand/stabilizing molecules facilitate the nanoparticles to bind on their surface, thereby, preventing the growth of particles during synthesis, which otherwise may lead to aggregation of the nanoparticles. We recently reported the facile synthesis of hydroxyl functionalized polymer based ZnS nanocomposites76 and have shown that large number of hydroxyl groups in the polymer matrix facilitates the complexation of metal ions (figure 6). The stabilizing molecules are attracted to the surface of the nanoparticles through chemisorption, electrostatic attraction or hydrophobic interaction, due to functionalities present on the terminal end of the stabilizer.…”