scholarly journals Experimental Investigation of Chloride Uptake Performances of Hydrocalumite-Like Ca-Al LDHs with Different Microstructures

2020 ◽  
Vol 10 (11) ◽  
pp. 3760
Author(s):  
Shupeng Zhang ◽  
Feng Yu ◽  
Wenting He ◽  
Dapeng Zheng ◽  
Hongzhi Cui ◽  
...  
Keyword(s):  
Particle Size ◽  
Adsorption Capacity ◽  
Ph Value ◽  
Average Particle Size ◽  
Chloride Ion ◽  
Average Particle ◽  
Chloride Uptake ◽  
Reaction Solution ◽  
Interlayer Anion ◽  
Double Hydroxides

In this study, hydrocalumite-like Ca2Al-NO3− layered double hydroxides (Ca-Al LDHs) with different microstructures were synthesized. The crystalline properties, structure composition, morphology and particle size distribution of the Ca-Al LDH (CAL) samples were illustrated. To obtain the chloride uptake performances of CAL, the influences of contact time, initial concentration of Cl−, pH of reaction solution and coexistence anions on the chloride uptake were examined systematically. Compared to the CAL samples obtained at a higher aging temperature, CAL synthesized at 60 °C demonstrated the minimum average particle size (6.148 μm) and the best Cl− adsorption capacity (211.324 mg/g). Based on the test results, the main adsorption mechanism of chloride ion on CAL was recognized as an interlayer anion exchanging reaction other than the dissolution-precipitate mode. With the increase in the pH value of reaction solution from 7 to 13, it was found that the amount of chloride ion adsorbed by CAL increased slightly, and the solution could remain at relatively high pH value even after the adsorption. The presence of CO32− and SO42− reduced the adsorption capacity of CAL dramatically as compared with OH− due to the destruction of layered structure and the formation of precipitates (CaCO3 or CaSO4). The interference sequence of the investigated anions on the chloride uptake of CAL was SO42−, CO32− and OH−, and the order of interlayer anionic affinity was Cl− > OH− > NO3−. The results illustrated that the synthesized CAL could be used as a promising chloride ion adsorbent for the corrosion inhibition of reinforcement embedded cement-based materials.

scholarly journals Homogeneous Precipitation Synthesis and Magnetic Properties of Cobalt Ferrite Nanoparticles

2008 ◽  
Vol 2008 ◽  
pp. 1-4 ◽  
Author(s):  
Zhigang Liu ◽  
Xiaodong Li ◽  
Yonghua Leng ◽  
Jingbao Lian ◽  
Shaohong Liu ◽  
...  
Keyword(s):  
Particle Size ◽  
Magnetic Properties ◽  
Cobalt Ferrite ◽  
Ph Value ◽  
Average Particle Size ◽  
Spherical Shape ◽  
Average Particle ◽  
Homogeneous Precipitation ◽  
Transmission Electron ◽  
Reaction Solution

Magnetic nanoparticles (NPs) of cobalt ferrite have been synthesized via a homogeneous precipitation route using hexamethylenetetramine (HMT) as the precipitant. The particle size, crystal structure, and magnetic properties of the synthesized particles were investigated by X-ray diffraction, transmission electron microscopy, and vibrating sample magnetometer. The NPs are of cubic inverse spinel structure and nearly spherical shape. With the increase of oxidation time from 30 to 180 minutes in the reaction solution at90∘C, the average particle size increases from ~30 nm to ~45 nm. The as-synthesized NPs ~30 nm in size show higherMs(61.5 emu/g) and moderate Hc (945 Oe) andMr/Ms(0.45) value compared with the materials synthesized by coprecipitation method using NaOH as precipitate at high pH value.

Selection of Polyanions as Complexation Agent in the Formation of Nanochitosan by Polyelectrolyte Complex Method

2019 ◽  
Vol 948 ◽  
pp. 140-145
Author(s):  
Al Dina N. Khoerunisa ◽  
Prihati Sih Nugraheni ◽  
Mohammad Fahrurrozi ◽  
Wiratni Budhijanto
Keyword(s):  
Particle Size ◽  
Polyelectrolyte Complex ◽  
Ph Value ◽  
Average Particle Size ◽  
Aqueous Dispersion ◽  
Complex Method ◽  
Average Particle ◽  
Arabic Gum ◽  
Mixing Ratios ◽  
The Stability

The aqueous dispersion of nanochitosan was prepared by polyelectrolyte complex (PEC) method with various mixing ratios of chitosan and polyanions, i.e., chitosan-glucomannan, chitosan-hyaluronic acid, and chitosan-Arabic gum. The formation of nanochitosan was carried out by adding the polyanion solution dropwise into the acid solution of chitosan. The study aimed to determine the best polyanion among the variations tested in this study, concerning the targeted particle size and the stability of the dispersion over time. Particle size distribution was observed by Particle Size Analyzer (PSA). The result indicated that Arabic gum gave the smallest average particle size, i.e. 192.5 nm, at a chitosan/polyanion mass ratio of 3:1 and pH value of 4.

scholarly journals Fabrication of Caseinate Stabilized Thymol Nanosuspensions via the pH-Driven Method: Enhancement in Water Solubility of Thymol

Foods ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 1074
Author(s):  
Wei Zhou ◽  
Yun Zhang ◽  
Ruyi Li ◽  
Shengfeng Peng ◽  
Roger Ruan ◽  
...  
Keyword(s):  
Particle Size ◽  
Water Solubility ◽  
Ph Value ◽  
Average Particle Size ◽  
Amorphous State ◽  
Average Particle ◽  
X Ray Diffraction ◽  
Commercial Products ◽  
Long Term Storage

Thymol has been applied as a spice and antibacterial agent in commercial products. However, the utilization of thymol in the food and pharmaceutical field has recently been limited by its poor water solubility and stability. In this work, a caseinate-stabilized thymol nanosuspension was fabricated by pH-driven methods to overcome those limitations. Firstly, the chemical stability of thymol at different pH value conditions was investigated. The physiochemical properties of thymol nanosuspensions were then characterized, such as average particle size, zeta potential, encapsulation efficiency, and loading capacity. Meanwhile, the X-ray diffraction results showed that thymol was present as an amorphous state in the nanosuspensions. The thermal stability of thymol was slightly enhanced by encapsulation through this process, and the thymol nanosuspensions were stable during the long-term storage, and the average particle size of nanosuspensions showed that there was no aggregation of nanosuspensions during storage and high temperature. Finally, the antimicrobial activity of thymol nanosuspensions was evaluated by investigating the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) against Salmomella enterca, Staphlococcus aureus, Escherichia coli, and Listeria monocytogenes. These results could provide useful information and implications for promoting the application of thymol in food, cosmetic, and pharmaceutical commercial products.

Ultrafine TiO2 Powders Prepared from Aqueous TiCl4 Solutions at Room Temperature

2007 ◽  
Vol 353-358 ◽  
pp. 2135-2138
Author(s):  
Hong Liang Yi ◽  
Jie Zhang ◽  
Ming Tu Ma ◽  
Hao Zhang ◽  
Bong Ho Lee ◽  
...  
Keyword(s):  
Particle Size ◽  
Room Temperature ◽  
Ph Value ◽  
Anatase Phase ◽  
Average Particle Size ◽  
Rutile Phase ◽  
Average Particle ◽  
Spectral Peaks ◽  
Scherrer Formula ◽  
Stock Solutions

Ultrafine TiO2 powders as rutile and anatase phase were simply precipitated at room temperature for only tens of hours by simply controlling the pH value and Ti4+ concentration via aqueous TiCl4 solution. Under the optimal pH value and Ti4+ concentration, the average particle size of powders with rutile phase was 3.7nm, while that of powders with anatase phase was 3.0nm. The average particle size was calculated from the broadening of corresponding X-ray spectral peaks by Scherrer formula. In addition, 3.0 mol.l-1 are suggested to be used as concentration of stock solutions instead of the current concentration 2.0 mol.l-1.

The Effect of the Malt Grinding Degree on the pH Value and Extract Content in Beer Mash

2018 ◽  
Vol 22 (4) ◽  
pp. 43-49
Author(s):  
Marcin Natoniewski ◽  
Leszek Rydzak ◽  
Agata Wyciszkiewicz ◽  
Tomasz Guz
Keyword(s):  
Particle Size ◽  
Food Production ◽  
Ph Value ◽  
Average Particle Size ◽  
Average Particle ◽  
Malt Extract ◽  
Chemical Changes ◽  
Extract Content ◽  
Physical And Chemical ◽  
Degree Of Fragmentation

AbstractIn recent years, a dynamic development of brewing has been observed. Increasingly, production of malt and beer takes place even in smaller industrial factories, breweries restaurants or at home. Extraction is a process applied in a variety of industries, including food production, as a way of extracting specific ingredients from their mixtures. As a result of this process, not only sugars, proteins, fats, enzymes, vitamins, colorants, fragrances and flavors, but also malt and hop extracts are being isolated. In the process of mashing, in which the malt ingredients are being extracted, many biochemical, physical and chemical changes take place. The aim of the study was to analyze the effect of the degree of fragmentation of pilsner type malt on the amount of extract obtained and the pH of the mash. It has been observed that the degree of malt fragmentation has a significant effect on the content of the extract in the mash: the more fragmented malt, the more malt extract in mash produced using the malt. It has also been found that the pH of the mash increases with the average particle size of malt.

Synthesis of PbS Nanocrystals by Heterogeneous Reaction

2014 ◽  
Vol 809-810 ◽  
pp. 26-30
Author(s):  
Rong Liang Zhang ◽  
Shu Zhen Tang
Keyword(s):  
Particle Size ◽  
Size Distribution ◽  
Ph Value ◽  
Heterogeneous Reaction ◽  
Nitrate Solution ◽  
Average Particle Size ◽  
Lead Nitrate ◽  
Average Particle ◽  
Pbs Nanocrystals ◽  
Distribution Ranges

PbS nanocrystals was synthesized by a heterogeneous reaction of hydrogen sulfide gas and lead nitrate solution containing EDTA in ethanol. The influenceof initial molar concentration ratio of EDTA/Pb (NO3)2 (CEDTA/CPb (NO3)2), volume ratio of ethanol/water (Vethanol/VH2O), pH value and flux of H2S on the particle size of PbS were investigated. The structure, morphology, particle size, and particle size distribution ranges of PbS were characterized by XRD, FE-SEM, and laser particle size analyzer, respectively. Increasing CEDTA/CPb (NO3)2, Vethanol/VH2O, and pH value, as well as decreasing the flux of H2S decrease the particle size of PbS. PbS nanocrystals have an average particle size of 69 nm, a narrow size distribution, and a quasi-spherical shape when CEDTA/CPb (NO3)2 is 1, Vethanol/VH2O is 1, pH is 3.5, and the flux of H2S is 20 ml/min.

Adsorption of Hazardous Heavy Metals Using Reactive Inorganic Agents in Synthetic Wastewater

2010 ◽  
Vol 658 ◽  
pp. 5-8
Author(s):  
Jong Oh Kim ◽  
Jin Woo Lee
Keyword(s):  
Heavy Metals ◽  
Particle Size ◽  
Zeta Potential ◽  
Adsorption Capacity ◽  
Average Particle Size ◽  
Synthetic Wastewater ◽  
Average Particle ◽  
Xrf Analysis ◽  
Reactive Agents ◽  
Main Components

This study focused on the adsorption characteristics of hazardous heavy metals using reactive inorganic agents in synthetic wastewater. Basic properties of five reactive agents were analyzed by zeta potential, particle size, XRF and SEM. Zeta potential of five adsorbents was 45, 7, 14, -2 and 45 mV, respectively. Average particle size was in the range of 1.4 to 9㎛. By XRF analysis, main components were Na, Al, Si, S and Fe in reactive agents and no great differences in Mg, K, Ca and Ti components. As, Zn, Ni, Cu, Cr, Cd and Pb were used as target heavy metals. Adsorption capacity of Pb and Cu was in the order: TN 315Ny-T3>TN820L>TN315NY.

scholarly journals Preparation and Evaluation of Sunflower Oil Nanoemulsion As a Sunscreen

2019 ◽  
Vol 7 (22) ◽  
pp. 3757-3761
Author(s):  
Anayanti Arianto ◽  
Cindy Cindy
Keyword(s):  
Particle Size ◽  
High Temperature ◽  
Low Temperature ◽  
Sunflower Oil ◽  
Room Temperature ◽  
Ph Value ◽  
Average Particle Size ◽  
Tween 80 ◽  
Average Particle ◽  
Spontaneous Emulsification

BACKGROUND: There are a lot of different types of sunscreen products (oils, sticks, gels, creams, lotions) which can be found on the world's market. Sunscreen product that contains active chemical ingredients sometimes has harmful effects on the skin. Sunflower oil contains vitamin E and acts as a natural sunscreen which can absorb UVB light. The average droplet size of nanoemulsion is between 100 and 500 nm and do not show the problems of stability (creaming, flocculation, coalescence, and sedimentation), which are commonly associated with macroemulsions. AIM: The aim of this study was to prepare and evaluate the sunflower oil nanoemulsion as a sunscreen. METHODS: Sunflower oil nanoemulsions were prepared by spontaneous emulsification method with 3 formulas F1 (Tween 80 38%, sorbitol 22%), F2 (Tween 80 36%, sorbitol 24%), F3 (Tween 80 34%, sorbitol 26%) and 5% sunflower oil as a sunscreen substance. The nanoemulsions were evaluated for particle size, physical stability in room temperature (25 ± 2°C), low temperature (4 ± 2°C) and high temperature (40 ± 2°C) during experiment for 12 weeks of storage, centrifugation at 3750 rpm for 5 hours, viscosity, pH, freeze-thaw test and sun protection value (SPF) value by in vitro. RESULTS: The results of nanoemulsion evaluation showed that nanoemulsion formula F1 had the smallest average particle size of 124.47 nm with yellowish colour, clear, transparent, pH value (6.5 ± 0.1), viscosity value (225 ± 25 cP), did not show any separation or creaming in the centrifugation, and stable during experiment for 12 weeks of storage at room temperature, low temperature and high temperature. The SPF value of all nanoemulsion preparations was higher than that of the emulsion. CONCLUSION: The preparation of the sunflower oil nanoemulsion with a ratio of Tween 80 and sorbitol (38: 22) produces a stable nanoemulsion during the experiment for 12 weeks storage at the room, low and high temperature. The nanoemulsion preparation has higher SPF values compared to the emulsion. This nanoemulsion formulation could be considered more effective in sunscreen cosmetic use compare to the emulsion.

Copper (II) Oxide Powder Prepared by Low Temperature Hydrothermal Method

2020 ◽  
Vol 861 ◽  
pp. 270-276
Author(s):  
Pusit Pookmanee ◽  
Maneerat Mueangjai ◽  
Sukon Phanichphant ◽  
Chanchana Thanachayanont
Keyword(s):  
Particle Size ◽  
Low Temperature ◽  
Hydrothermal Method ◽  
Ph Value ◽  
Average Particle Size ◽  
Fine Powder ◽  
Chemical Compositions ◽  
Average Particle ◽  
Mixed Solution ◽  
X Ray

In this research, CuO powder was prepared by low temperature hydrothermal method. Copper (II) nitrate trihydrate (Cu (NO3)2.3H2O) and sodium hydroxide (NaOH) were used as the starting precursors. The final pH value of the mixed solution was adjusted to 9 by 4M NaOH and treated at 100 oC and 200 oC for 4 and 6 h. The black fine powder was obtained after dried at 80 oC for 4 h. The phase was characterized by X-ray diffraction (XRD). A single phase of monoclinic structure of CuO powder prepared by low temperature hydrothermal method at 200 oC for 4 and 6 h was obtained without calcination step. The morphology and particle size were investigated by scanning electron microscopy (SEM). The morphology was flower-like in shape and the average particle size in range of 0.3×0.7 μm. The element composition was indicated by energy dispersive X-ray spectrometry (EDX). The chemical compositions showed the characteristic X-ray energy of copper (Kα = 0.95 keV) and oxygen (Kα = 0.53 keV). The functional group was indentified by fourier transform spectrophotometry (FTIR). The wavenumber at 433-531 cm-1 was corresponded to vibration of Cu-O stretching.

Preparation of thermal transfer ink using disperse fluorescent yellow 82 for polyester substrates

2014 ◽  
Vol 43 (2) ◽  
pp. 92-96 ◽  
Author(s):  
Yufei Xiu ◽  
Qiankun Shen ◽  
Fei Fan ◽  
Chaoxia Wang
Keyword(s):  
Particle Size ◽  
Image Quality ◽  
Diethylene Glycol ◽  
Ph Value ◽  
Average Particle Size ◽  
Average Particle ◽  
Polyester Fabrics ◽  
Content Type ◽  
Thermal Transfer ◽  
Line Image

Purpose – A disperse fluorescent yellow paste was mixed with a dispersant naphthalene sulfonic derivative via wet grinding process to prepare thermal transfer ink with good fluorescence. The paper aims to discuss these issues. Design/methodology/approach – The surface tension, viscosity, pH value, zeta potential, stability and the morphology of ink samples were tested after the storing process. Findings – The morphology of paste was homogeneous nearly spherical nanoparticles and the particle size was about 100 nm from the transmission electron microscopy (TEM), which was similar to the average particle size obtained from the particle size analyser. Research limitations/implications – The paste particle size was 126.8 nm after storing at 50°C for one week. The addition of diethylene glycol was conducive to high fluorescent reflectivity and gave good line image quality both in warp and weft directions due to the low viscosity. Inkjet printed polyester fabrics achieved excellent rubbing, laundering and thermal subliming fastnesses. Originality/value – The polyester fabrics thermal transferred with the ink contained diethylene glycol represented higher fluorescent reflectivity and gave better line image quality both in warp and weft directions. The inkjet printed polyester fabrics showed excellent colour reproducibility and all the fastnesses, including rubbing, laundering and thermal subliming, were higher than Grade 4.

Sign in / Sign up

Export Citation Format

Share Document