scholarly journals Physical and Chemical Fundamentals of Sodium Phosphate Use in Foundry Production

2020 ◽  
Vol 21 (4) ◽  
pp. 756-763
Author(s):  
M.V. Tyshkovets ◽  
R.V. Liutyi ◽  
D.V. Liuta ◽  
O.I. Sheiko
Keyword(s):  
Orthophosphoric Acid ◽  
Sodium Tripolyphosphate ◽  
Sodium Pyrophosphate ◽  
Binding Potential ◽  
Mass Ratio ◽  
Global Trends ◽  
Binder Material ◽  
Sodium Phosphates ◽  
Physical And Chemical ◽  
Atomic Radii

The technology of synthesis of inorganic binder material based on sodium tripolyphosphate Na5P3O10 and orthophosphoric acid has been developed. The sequence of physicochemical transformations in this system, as well as the optimal mass ratio of orthophosphoric acid and sodium tripolyphosphate are established. The research uses methods of quantitative and qualitative X-ray phase analysis, differential thermal analysis, standard methods of testing samples for compressive strength. The ratios of the atomic radii of the cation (Na) and the anion (P2O7), as well as the presence of hydrogen bonds, provide a significant increase in the binding potential compared to other sodium phosphates. It was found that the strengthening of mixtures with 2…8 mass parts including sodium pyrophosphate, the filler of which is quartz-based sand, occurs as intensely as possible when heated to 150°C. A further increase in temperature above 250 °C leads to the conversion of sodium pyrophosphate to ordinary (non-polymeric) metaphosphate NaPO3, which exists without changes in chemical structure up to 1000°C. The developed binder material, given the global trends of decarbonization and resource conservation, is a competitive alternative to widely used synthetic resins and other organic materials. It does not contain harmful substances and does not emit dangerous products when heated.

Chitosan-based Magnetic Composites - Efficient Adsorbents for Removal of Pb(II) and Cu(II) from Aqueous Mono and Bicomponent Solutions

2018 ◽  
Vol 69 (9) ◽  
pp. 2323-2330 ◽  
Author(s):  
Daniela C. Culita ◽  
Claudia Maria Simonescu ◽  
Rodica Elena Patescu ◽  
Nicolae Stanica
Keyword(s):  
Aqueous Solutions ◽  
Metal Ions ◽  
Chemical Properties ◽  
Order Kinetic ◽  
Mass Ratio ◽  
Magnetic Adsorbent ◽  
Magnetic Composites ◽  
Initial Ph ◽  
Order Kinetic Model ◽  
Physical And Chemical

A series of three chitosan-based magnetic composites was prepared through a simple coprecipitation method. It was investigated the influence of mass ratio between chitosan and magnetite on the physical and chemical properties of the composites in order to establish the optimum conditions for obtaining a composite with good adsorption capacity for Pb(II) and Cu(II) from mono and bicomponent aqueous solutions. It was found that the microspheres prepared using mass ratio chitosan / magnetite 1.25/1, having a saturation magnetization of 15 emu g--1, are the best to be used as adsorbent for the metal ions. The influence of different parameters such as initial pH values, contact time, initial concentration of metal ions, on the adsorption of Pb(II) and Cu(II) onto the chitosan-based magnetic adsorbent was investigated in details. The adsorption process fits the pseudo-second-order kinetic model in both mono and bicomponent systems, and the maximum adsorption capacities calculated on the basis of the Langmuir model were 79.4 mg g--1 for Pb(II) and 48.5 mg g--1 for Cu(II) in monocomponent systems, while in bicomponent systems were 88.3 and 49.5 mg g--1, respectively. The results revealed that the as prepared chitosan-based magnetic adsorbent can be an effective and promising adsorbent for Pb(II) and Cu(II) from mono and bicomponent aqueous solutions.

scholarly journals A chemical method of the production of "heavy" sodium tripolyphosphate with the high content of Form I or Form II

2009 ◽  
Vol 11 (2) ◽  
pp. 13-20 ◽  
Author(s):  
Marcin Banach ◽  
Zygmunt Kowalski ◽  
Zbigniew Wzorek ◽  
Katarzyna Gorazda
Keyword(s):  
Bulk Density ◽  
Chemical Method ◽  
Sodium Tripolyphosphate ◽  
Laundry Detergent ◽  
Detergent Builder ◽  
High Bulk Density ◽  
Sodium Phosphates ◽  
High Bulk

A chemical method of the production of "heavy" sodium tripolyphosphate with the high content of Form I or Form II Sodium tripolyphosphate STPP is used in laundry detergent as a detergent "builder". The paper presents the chemical method of obtaining "heavy", i.e. with higher bulk density granulated sodium tripolyphosphate. The bulk density of sodium tripolyphosphate was increased by preparing a mixture of the dried sodium phosphates, the recycled subgrain of STPP and water in specific proportions and calcining this mixture for 1 hour at 400°C and 550°C (to obtain a proper STPP form) in the chamber kiln. This method allows producing the granular sodium tripolyphosphate with high bulk density (1.04-1.07 kg/dm3) and a high content of Form I or Form II, respectively.

scholarly journals Optimization of Chitosan–Alginate Microparticles for Delivery of Mangostins to the Colon Area Using Box–Behnken Experimental Design

2020 ◽  
Vol 21 (3) ◽  
pp. 873 ◽  
Author(s):  
Kamarza Mulia ◽  
Ameninta Cesanina Singarimbun ◽  
Elsa Anisa Krisanti
Keyword(s):  
Calcium Chloride ◽  
Sodium Tripolyphosphate ◽  
Chloride Concentration ◽  
Release Profile ◽  
Significant Variable ◽  
Mass Ratio ◽  
Box Behnken Design ◽  
Cumulative Release ◽  
Independent Variables ◽  
Sequential Release

Chitosan-alginate microparticles loaded with hydrophobic mangostins present in the mangosteen rind extract have been formulated and optimized for colon-targeted bioactive drug delivery systems. The chitosan–mangostin microparticles were prepared using the ionotropic gelation method with sodium tripolyphosphate as the cross-linking agent of chitosan. The chitosan–mangostin microparticles were then encapsulated in alginate with calcium chloride as the linking agent. The mangostin release profile was optimized using the Box–Behnken design for response surface methodology with three independent variables: (A) chitosan–mangostin microparticle size, (B) alginate:chitosan mass ratio, and (C) concentration of calcium chloride. The following representative equation was obtained: percent cumulative release of mangostins (10 h) = 59.51 − 5.16A + 20.00B − 1.27C − 1.70AB − 5.43AC − 5.04BC + 0.0579A2 + 10.25B2 + 1.10C2. Cumulative release of 97% was obtained under the following optimum condition for microparticle preparation: chitosan–mangosteen particle size < 100 µm, alginate:chitosan mass ratio of 0.5, and calcium chloride concentration of 4% w/v. The alginate to chitosan mass ratio is the statistically significant variable in the optimization of sequential release profile of mangostins in simulated gastrointestinal fluids. Furthermore, a sufficient amount of alginate is necessary to modify the chitosan microparticles and to achieve a complete release of mangostins. The results of this work indicate that the complete release of mangostins to the colon area can be achieved using the chitosan–alginate microparticles as the bioactive delivery system.

Poloxamer Modified Chitosan Nanoparticles for Vaginal Delivery of Acyclovir

2021 ◽  
Vol 08 ◽  
Author(s):  
Sanjeevani Deshkar ◽  
Sumit Sikchi ◽  
Anjali Thakre ◽  
Rupali Kale
Keyword(s):  
Particle Size ◽  
Zeta Potential ◽  
Sodium Tripolyphosphate ◽  
Chitosan Nanoparticles ◽  
Drug Uptake ◽  
Mass Ratio ◽  
Modified Chitosan ◽  
Chitosan Nanoparticle ◽  
Nanoparticle Formulation

Objective: The aim of the present study was to design a surface modified chitosan nanoparticle system for vaginal delivery of Acyclovir for effective drug uptake into vaginal mucosa. Method: Acyclovir loaded chitosan nanoparticles, with and without modification by poloxamer 407, were prepared by ionic gelation method. The effects of two independent variables, chitosan to sodium tripolyphosphate mass ratio (X1) and acyclovir concentration (X2), on drug entrapment in nanoparticles, were studied using 32 full factorial design. The surface response and counter plots were drawn to facilitate an understanding of the contribution of the variables and their interaction. The nanoparticles were evaluated for drug entrapment, size with zeta potential, morphological analysis by TEM, solid state characterization by FTIR, DSC, XRD, in vitro dissolution, in vitro cell uptake using HeLa cell line and in vivo vaginal irritation test in Wistar rats. Results: Chitosan nanoparticle formulation with chitosan to sodium tripolyphosphate mass ratio of 2:1 and acyclovir concentration of 2 mg/mL resulted in highest entrapment efficiency. Resulting nanoparticles revealed spherical morphology with particle size of 191.2 nm. The surface modification of nanoparticles with Poloxamer resulted in higher drug entrapment (74.3±1.5%), higher particle size (391.1 nm) as a result of dense surface coating, lower zeta potential and sustained drug release compared to unmodified nanoparticles. The change in the crystallinity of drug during nanoparticle formulation was observed in DSC and XRD study. Cellular uptake of Poloxamer modified chitosan nanoparticles was found to be higher than chitosan nanoparticles in HeLa cells. Safety of nanoparticle formulations by vaginal route was evident when tested in female rats. Conclusion: Conclusively, Poloxamer modified CH NP could serve as a promising and safe delivery system with enhanced cellular drug uptake.

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