Preparation and Characterization of Poly(Dimethyl Diallyl Ammonium Chloride)/Modified SiO2 Spherical Brushes

2015 ◽  
Vol 731 ◽  
pp. 569-572 ◽  
Author(s):  
Na Su ◽  
Zheng Min Cao

Novel cationic spherical polyelectrolyte brushes (CSPB) consisting of γ-methacryloxypropyl trimethoxy-silane (KH-570) modified SiO2cores and poly (Dimethyl diallyl ammonium chloride) (PDMDAAC) brushes were prepared by conventional free radical polymerization. The resulting CSPB were characterized by Fourier transform infrared spectroscopy (FTIR), Transmission electron microscopy (TEM), Scanning electron microscopy (SEM), and Thermo-gravimetric analysis (TGA). After cleaving the polyelectrolyte chains from the anchoring surface, the molecular weight of brushes was 1.824×103gmol-1from Gel Permeation Chromatography (GPC) measurements.

Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1712
Author(s):  
Appusamy Muthukrishnaraj ◽  
Salma Ahmed Al-Zahrani ◽  
Ahmed Al Otaibi ◽  
Semmedu Selvaraj Kalaivani ◽  
Ayyar Manikandan ◽  
...  

Towards the utilization of Cu2O nanomaterial for the degradation of industrial dye pollutants such as methylene blue and methyl orange, the graphene-incorporated Cu2O nanocomposites (GCC) were developed via a precipitation method. Using Hummers method, the grapheme oxide (GO) was initially synthesized. The varying weight percentages (1–4 wt %) of GO was incorporated along with the precipitation of Cu2O catalyst. Various characterization techniques such as Fourier-transform infra-red (FT-IR), X-ray diffraction (XRD), UV–visible diffused reflectance (UV-DRS), Raman spectroscopy, thermo gravimetric analysis (TGA), energy-dispersive X-ray analysis (EDX), and electro chemical impedance (EIS) were followed for characterization. The cabbage-like morphology of the developed Cu2O and its composites were ascertained from field-emission scanning electron microscopy (FESEM) and high-resolution transmission electron microscopy (HR-TEM). In addition, the growth mechanism was also proposed. The results infer that 2 wt % GO-incorporated Cu2O composites shows the highest value of degradation efficiency (97.9% and 96.1%) for MB and MO at 160 and 220 min, respectively. Further, its catalytic performance over visible region (red shift) was also enhanced to an appreciable extent, when compared with that of other samples.


2017 ◽  
Vol 50 ◽  
pp. 18-31 ◽  
Author(s):  
Rudzani Sigwadi ◽  
Simon Dhlamini ◽  
Touhami Mokrani ◽  
Patrick Nonjola

The paper presents the synthesis and investigation of zirconium oxide (ZrO2) nanoparticles that were synthesised by precipitation method with the effects of the temperatures of reaction on the particles size, morphology, crystallite sizes and stability at high temperature. The reaction temperature effect on the particle size, morphology, crystallite sizes and stabilized a higher temperature (tetragonal and cubic) phases was studied. Thermal decomposition, band structure and functional groups were analyzed by Brunauer-Emmett-Teller (BET), Scanning Electron Microscopy (SEM), Transmission electron microscopy (TEM), X-ray diffraction (XRD), Thermo-gravimetric analysis (TGA) and Fourier transform infrared (FT-IR). The crystal structure was determined using X-ray diffraction. The morphology and the particle size were studied using (SEM) and (TEM). The shaped particles were confirmed through the SEM analysis. The transmission electron microscopic analysis confirmed the formation of the nanoparticles with the particle size. The FT-IR spectra showed the strong presence of ZrO2 nanoparticles.


2019 ◽  
Vol 11 (11) ◽  
pp. 1064-1070 ◽  
Author(s):  
Nkosinathi G. Dlamini ◽  
Albertus K. Basson ◽  
V. S. R. Rajasekhar Pullabhotla

Bioflocculant from Alcaligenis faecalis HCB2 was used in the eco-friendly synthesis of the copper nanoparticles. Nanoparticles were characterized using a scanning electron microscope (SEM), transmission electron microscopy (TEM), UV-visible spectroscopy, thermo gravimetric analysis (TGA) and Fourier Transform Infrared Spectroscopy (FT-IR). The transmission electron microscopy images showed close to spherical shapes with an average particle size of ∼53 nm. Energy-dispersive X-ray spectroscopy analysis confirmed the presence of the Cu nanopartilces and also the other elements such as O, C, P, Ca, Cl, Na, K, Mg, and S originated from the bioflocculant. FT-IR results showed the presence of the –OH and –NH2 groups, aliphatic bonds, amide and Cu–O bonds. Powder X-ray diffraction peaks confirmed the presence of (111) and (220) planes of fcc structure at 2 of 33° and 47° respectively with no other impurity peaks.


2016 ◽  
Vol 27 (2) ◽  
pp. 60 ◽  
Author(s):  
Rudzani A Sigwadi ◽  
Sipho E Mavundla ◽  
Nosipho Moloto ◽  
Touhami Mokrani

Zirconia nanoparticles were prepared by the precipitation and ageing methods. The precipitation method was performed by adding ammonium solution to the aqueous solution of zirconium chloride at room temperature. The ageing method was performed by leaving the precipitate formed in the mother liquor in the glass beaker for 48 hours at ambient temperatures. The nanoparticles from both methods were further sulphated and phosphated to increase their acid sites. The materials prepared were characterised by X-ray diffraction (XRD), thermo-gravimetric analysis (TGA), Brunauer-EmmettTeller (BET), transmission electron microscopy (TEM) and scanning electron microscopy (SEM) methods. The XRD results showed that the nanoparticles prepared by the precipitation method contained mixed phases of tetragonal and monoclinic phases, whereas the nanoparticles prepared by ageing method had only tetragonal phase. The TEM results showed that phosphated and sulphated zirconia nanoparticles obtained from the ageing method had a smaller particle size (10–12 nm) than the nanoparticles of approximately 25–30 nm prepared by precipitation only. The BET results showed that the ZrO2 nanoparticles surface area increased from 32 to 72 m2/g when aged.


2021 ◽  
Vol 8 (1) ◽  
pp. 95-103
Author(s):  
Husin et al. ◽  

River tamarind or scientifically Leucaena leucocephala, is one of the underutilized nanocellulose resources with the potential to be used in reinforcement materials. This work evaluated the use of the insoluble residual waste or marc obtained during the isolation of galactomannan from Leucaena leucocephala seed (LLS) as a feedstock of cellulose to obtain cellulose nanocrystals by a two-step acid hydrolysis followed by its characterization and morphological study. The first step involved acid hydrolyzation of the hemicellulose and lignin from LLS, while the second step dealt with the removal of the amorphous region to produce crystalline LLS nanocrystals (NLLS). The physicochemical properties of nanocrystals were characterized using the Fourier transform infrared spectroscopy (FTIR), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), particle size analyzer (PSA), X-ray diffractometer (XRD), thermal gravimetric analysis (TGA), and gel permeation chromatography (GPC). The NLLS isolated showed a rod-like structure in the range of 70–90nm in diameter with a crystallinity index of 76% and thermal stability at 264°C. PSA indicates that 97.5% of the size distribution of NLLS was below 136.9nm. GPC analysis also revealed that the sulphuric acid hydrolyzation during the second step caused a reduction in the molecular weight due to the cleaving of glycosidic bonds in the structure. These results indicated that LLS waste is a potential feedstock for cellulose nanocrystals preparation.


2014 ◽  
Vol 692 ◽  
pp. 347-351
Author(s):  
Qian Qian Dong ◽  
Hou Bin Li ◽  
Pan Zhang ◽  
Qi Zhang ◽  
Hao Li

The synthesis of polyaniline (PANI) doped with anionic spherical polyelectrolyte brushes (ASPB) (PANI/ASPB nanocomposite) by means of in situ chemical oxidative polymerization were presented. The PANI/ASPB nanocomposite was characterized by Fourier trans-form infrared spectroscopy (FTIR), Scanning electron microscopy (SEM), Energy dispersive x-ray detector (EDX), and Thermo-gravimetric analysis (TGA). Results showed that PANI/ASPB nanocomposite was successfully fabricated with regular morphology. Investigation of the electrical conductivity at room temperature showed that the electrical conductivity of PANI/ASPB nanocomposite was 9.03 S/cm, which was higher than that of PANI (2.7 S/cm). The measurement of dispersity demonstrated that PANI/ASPB nanocomposite had enhanced dispersity in water.


Molecules ◽  
2021 ◽  
Vol 26 (1) ◽  
pp. 218
Author(s):  
Tong Luo ◽  
Chao Wang ◽  
Xingxiang Ji ◽  
Guihua Yang ◽  
Jiachuan Chen ◽  
...  

Lignin nanomaterials have wide application prospects in the fields of cosmetics delivery, energy storage, and environmental governance. In this study, we developed a simple and sustainable synthesis approach to produce uniform lignin nanoparticles (LNPs) by dissolving industrial lignin in deep eutectic solvents (DESs) followed by a self-assembling process. LNPs with high yield could be obtained through nanoprecipitation. The LNPs were characterized by dynamic light scattering (DLS), transmission electron microscopy (TEM), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and gel permeation chromatography (GPC). Distinct LNPs could be produced by changing the type of DES, lignin sources, pre-dropping lignin concentration, and the pH of the system. Their diameter is in the range of 20–200 nm and they show excellent dispersibility and superior long-term stability. The method of preparing LNPs from lignin–DES with water as an anti-solvent is simple, rapid, and environmentally friendly. The outcome aids to further the advancement of lignin-based nanotechnology.


NANO ◽  
2013 ◽  
Vol 08 (02) ◽  
pp. 1350012
Author(s):  
G. R. BARDAJEE ◽  
F. MIZANI ◽  
I. ROSTAMI ◽  
Z. HOOSHYAR ◽  
F. M. MINABIAN

The optical properties of CdSe quantum dots (QDs) capped by thioglycolic acid (TGA) before and after surface modification with poly (acrylic acid) grafted onto salep (salep-g-PAA), as a biopolymer-based multidentate ligand, were examined. The results showed that the fluorescence intensity as well as the stability of CdSe QDs was incredibly increased after surface modification with the biopolymer-based ligand. To provide more evidence for the occurrence of surface modification, the prepared CdSe –salep-g-PAA QDs were characterized by thermo-gravimetric analysis (TG), transmission electron microscopy (TEM), scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FT-IR).


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