Effect of hexamethylene tetramine (HMTA) surfactant on the structural characteristics and photocatalytic activity of Cu-ZnO nanoparticle materials fabricated by the hydrothermal method

2021 ◽  
Vol 10 (3) ◽  
pp. xx-xx
Author(s):  
Mai Nguyen Thi Tuyet ◽  
Hue Dang Thi Minh ◽  
Huyen Tran Thi Thu ◽  
Lan Nguyen Thi ◽  
Nga Nguyen Kim ◽  
...  

The experiment had fabricated and studied the properties of ZnO and Cu doped ZnO nanoparticles with the change of the hexamethylene tetramine surfactant content (HMTA) with molar ratio Zn2 +: HMTA = 1: x; x = 1, 2 and 4. The methods were used to study the characteristics of materials such as: XRD, raman shift, SEM, reflection spectrum. The results show that, when the content of surfactant HMTA increased (1-4 mol versus the moles of Zn2+), the size of the nanorods crystals of fabricated materials had reduced from 64.5 to 21.7 nm. The reflectance spectrum of Cu doped ZnO materials samples was lower in the visible light region compared to pure ZnO samples. The photocatalytic properties for decomposition of methylene blue organic dye of the Cu doped ZnO sample (with the greatest concentration of HMTA surfactant of 4 mol versus the moles of Zn2+) reached 98% after 40 minutes of ultraviolet light irradiation, with the rate constant k= 0,13261 min-1.

Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1780
Author(s):  
Bao Le ◽  
Pham-Thi-Ngoc Anh ◽  
Seung-Hwan Yang

Polysaccharides are key bioactive compounds in lotus plumule tea, but their anti-diabetes activities remain unclear. The purpose of this study was to investigate the prebiotic activities of a novel polysaccharide fraction from the Nelumbo nucifera lotus plumule, and to examine its regulation of glucose metabolism in insulin-resistant HepG2 cells. The N. nucifera polysaccharide (NNP) was purified after discoloration, hot water extraction, ethanol precipitation, and DEAE-cellulose chromatography to obtain purified polysaccharide fractions (NNP-2). Fourier transform infrared spectroscopy was used to analyze the main structural characteristics and functional group of NNP-2. Physicochemical characterization indicated that NNP-2 had a molecular weight of 110.47 kDa and consisted of xylose, glucose, fructose, galactose, and fucose in a molar ratio of 33.4:25.7:22.0:10.5:8.1. The prebiotic activity of NNP-2 was demonstrated in vitro using Lactobacillus and Bifidobacterium. Furthermore, NNP-2 showed bioactivity against α-glucosidase (IC50 = 97.32 µg/mL). High glucose-induced insulin-resistant HepG2 cells were used to study the effect of NNP-2 on glucose consumption, and the molecular mechanism of the insulin transduction pathway was studied using RT-qPCR. NNP-2 could improve insulin resistance by modulating the IRS1/PI3K/Akt pathway in insulin-resistant HepG2 cells. Our data demonstrated that the Nelumbo nucifera polysaccharides are potential sources for nutraceuticals, and we propose functional food developments from the bioactive polysaccharides of N. nucifera for the management of diabetes.


1982 ◽  
Vol 152 (2) ◽  
pp. 888-892
Author(s):  
S Rottem ◽  
R M Cole ◽  
W H Habig ◽  
M F Barile ◽  
M C Hardegree

Tetanolysin binding to lipid vesicles was found to depend on the molar ratio of cholesterol to phospholipid, being low in vesicles containing up to 20 mol% cholesterol and high in vesicles containing more than 33 mol%. High concentrations of purified tetanolysin preparations formed arc- and ring-shaped structures. The structures were not readily detectable in diluted preparations unless incubated with lipid vesicles containing high molar ratios of cholesterol to phospholipid. It is suggested that the toxin is concentrated on the vesicles to local concentrations high enough to form the arcs and rings.


Author(s):  
Vinay Kumar ◽  
Rupinder Singh ◽  
Inderpreet Singh Ahuja

Construction is the part of human activity which is directly linked to urbanization for moving ahead on the path of growth and prosperity. Construction activities in past centuries are now part of our precious heritage. The repair and maintenance of heritage structures are of great importance for present-day researchers. One of the most common damage these century-long constructions faces are in form of surface cracks. In the present study, investigations were performed for a 3D printing-based customized solution for crack repair and maintenance of heritage structures. In this study, polyvinylidene fluoride (PVDF) polymer was reinforced with graphene (Gr) and Mn-doped ZnO nano-particles to prepare a smart composite material for crack repair and restoration. The composite was successfully 3D printed on fused deposition modeling (FDM) based 3D printer after investigating its rheological, thermal, and mechanical properties. The in-house developed composite was tested for smart characteristics to use as a programmable solution for filling cracks. The piezoelectric property and dielectric constant of 3D printed disk-shaped composite (PVDF-Gr-Mn-ZnO) were obtained after DC poling (to be used as stimulus) of the functional prototype. The results of the study suggest that the electro-active nature, volumetric change, and charge storing capacity of the additively manufactured composite may be used practically to acquire the shape of cavity/crack present in the constructed wall and repair the damages that occurred in a heritage site. The photoluminescence (PLS) and atomic force microscopy (AFM) analysis was used to ascertain the properties of the prepared composite. Also, the results obtained from the morphological analysis are reported to support the outcomes of the research.


2020 ◽  
Vol 1 (5) ◽  
pp. 1253-1261 ◽  
Author(s):  
Christian Mark Pelicano ◽  
Itaru Raifuku ◽  
Yasuaki Ishikawa ◽  
Yukiharu Uraoka ◽  
Hisao Yanagi

Strategic design of hierarachical core–shell heterostructure of H2O-oxidized ZnO nanorod@Mg-doped ZnO nanoparticles with enhanced charge-transport capabilities for optoelectronic devices.


2014 ◽  
Vol 685 ◽  
pp. 3-6
Author(s):  
Ying Lian Wang ◽  
Jun Yao Ye

Pure ZnO thin films and Ag doped ZnO thin films were prepared on quartz substrates by sol-gel process. Structural features and UV absorption spectrum have been studied by XRD and UV-Vis-Nir scanning spectrophotometer. Taking phenol as pollutants, further study of the effect of different annealing temperature and Ag dopant amount of ZnO films on photocatalytic properties was carried out. The results showed that, the optimal annealing temperature on photocatalytic degradation of phenol in this experiment was 300 °C, the best molar ratio of ZnO and Ag was 30:1, which was better than pure ZnO film greatly. Excellent adhesion, recyclable and efficient degradation Ag doped ZnO thin films were found in this experiment.


2015 ◽  
Vol 149 ◽  
pp. 70-73 ◽  
Author(s):  
Yongjin Luo ◽  
Kuncan Wang ◽  
Qingrong Qian ◽  
Weiwei Zheng ◽  
Hun Xue ◽  
...  

2011 ◽  
Vol 467-469 ◽  
pp. 1569-1574
Author(s):  
Shao Peng Wu ◽  
Zu Huang Zhu ◽  
Zhi Fei Liu ◽  
Wei Zhang

The structural characteristics of zeolite 4A make it to be the potential warm mix asphalt additive. Zeolite 4A containing crystal water can be synthesized with fly ash (FA) by fusion with sodium hydroxide prior to hydrothermal reaction. The influence of some factors on the water loss of synthesized zeolite 4A was investigated. The results indicate that the best technological conditions of synthesizing zeolite 4A containing crystal water with fly ash are as follows: the molar ratio of SiO2/A12O3 is 1.9; the molar ratio of Na2O/SiO2 is 2.0; the molar ratio of H2O/Na2O is 50; under the aging temperature of 65°C, the optimum aging time is 3 h; under the crystallization temperature of 90°C, the optimum crystallization time is 4 h.


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