ELECTROPHORESIS OF RESIN EMULSIONS: I. THE EFFECT OF EMULSIFYING AGENTS

1953 ◽  
Vol 31 (3) ◽  
pp. 287-296 ◽  
Author(s):  
L. A. Munro ◽  
F. H. Sexsmith
Keyword(s):  
Particle Size ◽  
Hydrogen Bonding ◽  
Vinyl Acetate ◽  
Electrolyte Concentration ◽  
Chemical Change ◽  
Charged Particles ◽  
Emulsifying Agent ◽  
Glass Cell ◽  
Partial Chemical

A modified Briggs electrophoretic glass cell was used to measure the mobility of over 2500 particles of vinyl acetate latices prepared with different emulsifying agents. Although anionic and cationic agents conferred negative and positive mobilities respectively, nonionic agents invariably resulted in negatively charged particles. This is attributed to partial chemical change to anionic materials or to hydrogen bonding and polarization processes. The nature of the emulsifying agent and electrolyte concentration rather than concentrations of the latex or particle size were the most significant variables affecting the mobility of any latex.

Chemical Transformation of Fe, Air & Water to Ammonia: Variation of Reaction Rate with Temperature, Pressure, Alkalinity and Iron

2018 ◽  
Author(s):  
Ping Peng ◽  
Fang-Fang Li ◽  
Xinye Liu ◽  
Jiawen Ren ◽  
jessica stuart ◽  
...  
Keyword(s):  
Particle Size ◽  
Reaction Rate ◽  
Electrolyte Concentration ◽  
Iron Concentration ◽  
Reaction Medium ◽  
Iron Particle ◽  
Intermediate Step ◽  
Ammonia Production ◽  
Pure Nitrogen ◽  
Alkaline Reaction

The rate of ammonia production by the <u>chemical </u>oxidation of iron, N<sub>2</sub>(from air or as pure nitrogen) and water is studied as a function of (1) iron particle size, (2) iron concentration, (3) temperature, (4) pressureand (5) concentration of the alkaline reaction medium. The reaction meduium consists of an aqueous solution of equal molal concentrations of NaOH and KOH (Na<sub>0.5</sub>K<sub>0.5</sub>OH). We had previously reported on the <u>chemical </u>reaction of iron and nitrogen in alkaline medium to ammonia as an intermediate step in the <u>electrochemical </u>synthesis of ammonia by a nano-sized iron oxide electrocatlyst. Here, the intermediate <u>chemical </u>reaction step is exclusively explored. The ammonia production rate increases with temperature (from 20 to 250°C), pressure (from 1 atm to 15 atm of air or N<sub>2</sub>), and exhibits a maximum rate at an electrolyte concentration of 8 molal Na<sub>0,5</sub>K<sub>0,5</sub>OH in a sealed N<sub>2</sub>reactor. 1-3 µm particle size Fe drive the highest observed ammonia production reaction rate. The Fe mass normalized rate of ammonia production increases with decreasing added mass of the Fe reactant reaching a maximum observed rate of 2.2x10<sup>-4</sup>mole of NH<sub>3</sub>h<sup>-1</sup>g<sup>-1</sup>for the reaction of 0.1 g of 1-3 µm Fe in 200°C 8 molal Na<sub>0.5</sub>K<sub>0.5</sub>OH at 15 atm. Under these conditions 5.1 wt% of the iron reacts to form NH<sub>3</sub>via the reaction N<sub>2</sub>+ 2Fe + 3H<sub>2</sub>O ®2NH<sub>3</sub>+ Fe<sub>2</sub>O<sub>3</sub>.

Evolution of multimodal particle size distribution in vinyl acetate/butyl acrylate emulsion copolymerizations

2003 ◽  
Vol 41 (14) ◽  
pp. 2232-2249 ◽  
Author(s):  
Charles D. Immanuel ◽  
Timothy J. Crowley ◽  
Edward S. Meadows ◽  
Cajetan F. Cordeiro ◽  
Francis J. Doyle
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Vinyl Acetate ◽  
Butyl Acrylate ◽  
Acrylate Emulsion

Miscibility and hydrogen bonding in blends of poly(vinyl acetate) with phenolic resin

Polymer ◽  
2002 ◽  
Vol 43 (8) ◽  
pp. 2479-2487 ◽  
Author(s):  
Mei-Wen Huang ◽  
Shiao-Wei Kuo ◽  
Hew-Der Wu ◽  
Feng-Chih Chang ◽  
Su-Yun Fang
Keyword(s):  
Hydrogen Bonding ◽  
Vinyl Acetate ◽  
Phenolic Resin

Influence of particle size on extraction from a charged bed – toward liquid marble formation

Soft Matter ◽  
2019 ◽  
Vol 15 (38) ◽  
pp. 7547-7556 ◽  
Author(s):  
Casey A. Thomas ◽  
Moe Kasahara ◽  
Yuta Asaumi ◽  
Benjamin T. Lobel ◽  
Syuji Fujii ◽  
...  
Keyword(s):  
Particle Size ◽  
Charged Particles ◽  
Liquid Marble

Larger particles are more readily extracted from an advancing bed of charged particles owing to decreased interparticle cohesion.

scholarly journals FORMULATION AND OPTIMIZATION OF NANOSUSPENSION FOR IMPROVING SOLUBILITY AND DISSOLUTION OF GEMFIBROZIL

2019 ◽  
Vol 12 (1) ◽  
pp. 157 ◽  
Author(s):  
Sanjeevani S Deshkar ◽  
Kiran G Sonkamble ◽  
Jayashri G Mahore
Keyword(s):  
Particle Size ◽  
Drug Release ◽  
Zeta Potential ◽  
Chemical Change ◽  
Fold Increase ◽  
Sonication Time ◽  
Scanning Calorimetry ◽  
Solubility In Water ◽  
Pure Drug

Objective: The study aims at the formulation and optimization of gemfibrozil (Gem) nanosuspension (NS) for improving its solubility and dissolution rate.Method: Gem NS was prepared by precipitation-ultrasonication method using ethanol as solvent, water as anti-solvent, and polyvinyl alcohol (PVA) as a stabilizer. A Box–Behnken design was employed to study the effect of the independent variables, Gem concentration in the organic phase (X1), PVA concentration (X2) and sonication time (X3) on the dependent variable, drug release after 90 min (Y). The resulting data were statistically analyzed and subjected to 3D response surface methodology to study the influence of variables on the response. NS was evaluated for particle size, zeta potential, solubility and in vitro drug release and characterized using Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), and X-ray diffractometry (XRD).Results: On the basis of the evaluation, NS4 formulation (with 80 mg/ml Gem, 0.5% PVA concentration, and 20 min of sonication time) demonstrated highest drug content with a particle size of 191.0 nm and zeta potential of −12.0 mV. Dissolution profiles of NS indicated 2.5-fold increase in drug release than pure drug. NS demonstrated 5- and 9-fold increase in solubility, in water, and phosphate buffer (pH 7.5), respectively, pure drug. DSC and XRD studies indicated changes in the crystallinity of Gem during NS formulation. No chemical change was evident in NS as indicated by FTIR.Conclusion: Gem NS formulation could serve as a promising approach for improving its solubility and dissolution rate.

scholarly journals Electrosynthesis of α-Fe2O3 in a Fe(s)|KCl(aq)||H2O(aq)|C(s) System

2018 ◽  
Vol 21 (4) ◽  
pp. 182-186 ◽  
Author(s):  
Nia Siskawati ◽  
Didik Setiyo Widodo ◽  
Wasino Hadi Rahmanto ◽  
Linda Suyati
Keyword(s):  
Particle Size ◽  
Electrolyte Solution ◽  
Oxidation Reaction ◽  
Electrolyte Concentration ◽  
Salt Bridge ◽  
Anode Chamber ◽  
Fe2o3 Particle ◽  
Electrolysis Method ◽  
Reduction And Oxidation

Research on α-Fe2O3 electrosynthesis has been performed in the system Fe(s)|KCl(aq)||H2O(aq)|C(s). Electrolysis produces a reduction and oxidation reaction so that it requires a proper electrolyte concentration in the process. The purpose of this study was to obtain α-Fe2O3 compounds, determine the products produced by FTIR and XRD, and determine the size of the grains of products with PSA. Electrolysis method of two compartment was used in this research. The cathode and anode compartments was connected with the salt bridge. In anode chamber containing electrolyte solution KCl was varied (0,2 M; 0,3 M; 0,4 M; 0,5 M and 0,6 M) whereas at cathode space there was aquades. Electrolysis was run at 12 V for 8 hours. The electrolysis result was then calcined for two hours at a temperature of 500°C. The resulting product was then characterized by (FTIR, XRD, and PSA). The resulting product is then characterized by (FTIR, XRD, and PSA). The results showed that brown ferrihydrite was obtained in a concentration of 0.2 M; 0.3 M; 0.4 M; 0.5 M and 0.6 M were 21.6 mg; 24.1 mg; 34.5 mg; 39.4 mg and 62.4 mg respectively. Ferrihydrite produced from electrolysis of KCl 0.4 M concentration was dark red The XRD results show the presence of α-Fe2O3 and PSA results show that the α-Fe2O3 particle size is 151.57-171.25 nm.

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