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1

Antimicrobial activity, viability, and physicochemicalproperties of an MTA-type cement with differentconcentrations of bismuth trioxide

Martínez-Hernández Miryam, Manzo-García Daniel, Ramírez-Ortega Juana Paulina, Arreguín-Cano Juan Antonio, Chávez-Cortéz Elda Georgina, Arenas-Alatorre Jesús Ángel, Rodríguez-Chávez Jacqueline Adelina, Flores-Ledesma Abigailt

Materials Science Poland

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2023

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Vol. 41, No. 2

339--353

EN

In medicine, bismuth is used as an antimicrobial agent. In dentistry, it is used primarily to increase radiopacity in someendodontic materials. The objective is to evaluate the antimicrobial activity, cell viability, pH, solubility, film thickness, andsetting time of a mineral trioxide aggregated (MTA)-types of cement with different concentrations of bismuth trioxide. Threeexperimental MTA-types of cement with a bismuth trioxide (Bi2O3) concentration of 15 wt%, 20 wt%, and 25 wt% were used.The antimicrobial activity test was conducted on Streptococcus mutans and Porphyromonas gingivalis strains. Cell viability wasmeasured by the quantitative colorimetric assay using the MTT (3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyltetrazolium bromide)assay on a mouse fibroblast cell line (L929). Solubility, film thickness, and setting time were performed according to ISO 6876.The lowest Bi2O3concentrations showed the best antimicrobial activity and cell viability. pH, solubility, setting time, and filmthickness did not show statistically significant differences between the different Bi2O3concentrations tested.

2

An approach to coupling the gas flow dynamics and thermodynamics of hydrogen solubility in L485ME steel grade for estimation of fracture toughness

Witek Maciej, Uilhoorn Ferdinand

Archives of Thermodynamics

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2023

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Vol. 44, no 4

381--403

EN

The paper presents the problem of coupling the gas flow dynamics in pipelines with the thermodynamics of hydrogen solubility in steel for the estimation of the fracture toughness. In particular, the influence of hydrogen blended natural gas transmission on hydrogen solubility and, consequently, on fracture toughness is investigated with a focus on the L485ME low-alloy steel grade. Hydraulic simulations are conducted to obtain the pressure and temperature conditions in the pipeline. The hydrogen content is calculated from Sievert’s law and, as a consequence, the fracture toughness of the base metal and heat-affected zone is estimated. Experimental data is used to define hydrogen-assisted crack size propagation in steel as well as to a plane strain fracture toughness. The simulations are conducted for a real natural gas transmission system and compared against the threshold stress intensity factor. The results showed that the computed fracture toughness for the heat-affected zone significantly decreases for all natural gas and hydrogen blends. The applied methodology allows for identification of the hydrogen-induced embrittlement susceptibility of pipelines constructed from thermomechanically rolled tubes worldwide most commonly used for gas transmission networks in the last few decades.

3

Modyfikacja estru naturalnego fulerenem C60

Szcześniak Dominika, Przybyłek Piotr, Marcinkowska Agnieszka, Lewandowska Aneta

Przegląd Elektrotechniczny

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2022

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R. 98, nr 10

136--139

PL

Artykuł dotyczy wybranych zagadnień związanych z zastosowaniem estrów naturalnych w transformatorach energetycznych. Przedstawiono zalety i wady tych cieczy. Wskazano jedno z głównych ograniczeń w ich stosowaniu związane ze słabą stabilnością oksydacyjną. W artykule opisano możliwości ograniczania procesu oksydacji estru naturalnego poprzez jego modyfikację przy użyciu fulerenu C60. Uzyskane wyniki badań potwierdziły możliwość rozpuszczenia fulerenu w estrze naturalnym oraz ograniczenia procesu utleniania estru.

EN

This article deals with selected issues related to the use of natural esters in power transformers. The advantages and disadvantages of these liquids are presented. One of the main limitations of their use, related to poor oxidation stability, is indicated. The paper describes the possibility of limiting the oxidation process of natural ester by modification with fullerene C60. The obtained results confirmed the possibility of dissolving fullerene in natural ester and limiting the ester oxidation process.

4

Microstructure and surface free energy of light-cured dental composites after their modification with liquid rubber

Sowa Monika, Przekora Agata, Pałka Krzysztof

Engineering of Biomaterials

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2022

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vol. 25, no. 164

9--15

EN

The use of liquid rubber as a component of light-cured dental composites is one of the methods of increasing their fracture toughness. It also reduces polymerization shrinkage and offers the potential to lower water sorption. The aim of the study was to evaluate the miscibility of liquid rubber in composite matrix resins as well as changes in the wettability and surface free energy (SFE) values of commercial lightcuring composites after their modification with liquid rubber. The research materials were Flow Art and Boston (Arkona) light-cured composites and resin mixtures used in their production. Liquid rubber Hypro 2000X168LC VTB (Huntsman Int.) was used as a modifier. The solubility of liquid rubber was assessed under light microscopy. The contact angle and SFE measurements were made on a DSA30 goniometer (Kruss) using water and diiodomethane. It was found that the liquid rubber solubility depended mainly on the viscosity of the resin, which was related to the amount of BisGMA. The resulting mixture showed good temporal stability without larger domains. The curing process released the liquid rubber as a separate phase formed as spherical domains. The morphology of these domains was homogeneous and their size did not exceed 50 µm in diameter. The presence of liquid rubber in modified composites increased their hydrophobicity and reduced the surface free energy value. The obtained properties might help to reduce the formation of bacterial biofilm on dental fillings.

5

The influence of electron and gamma irradiation on the properties of starch : PVA films : the effect of irradiation dose

Cieśla Krystyna A., Abramowska Anna

Nukleonika

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2021

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Vol. 66, No. 1

3--9

EN

The paper discusses the effect of ionizing radiation on the functional properties of the biodegradable starch:PVA films. The analysis is related to the possible use of the material for packing the products (particularly, food) that are predicted for radiation decontamination and to the potential modifi cation of the material by radiation treatment. Our previous results have shown that the infl uence of ionizing radiation on the films’ properties varied for the specific compositions (differing in starch:PVA ratio or the type of substrates) and depended on irradiation conditions. However, these studies considered only the irradiation performed in gamma chamber or in e-beam using a dose of 25 kGy. Therefore, the present study deals with the effect of the irradiations performed using various doses on the selected promising starch:PVA composition. The films characterized by starch:PVA weight ratio of 45:55 was obtained by solution casting and irradiated with fast electrons in air and with 60Co gamma rays in nitrogen applying the doses of 5, 10, 20, 25, 30, 50, and 75 kGy. No regular dependence has been noticed between the composition of films (differing in the starch and PVA content) and the intensities of the particular bands in the UV-VIS DRS spectra after irradiation. The results indicated strong interaction of the starch and PVA components in the films and the occurrence of specific reactions in each composition upon irradiation. No special differences were observed between tensile strength and Young’s modulus of the non-irradiated films characterized by the starch:PVA ratio equal to 45:55 and the samples irradiated using doses in the range of 5–75 kGy. Similarly, no differences were observed in both cases between the swelling capability of the non-irradiated and the irradiated films. However, it can be deduced that solubility in water increased when the radiation dose increased. The results show that using the doses till the range 25 kGy does not cause an essential change of all the examined properties of the starch:PVA (45:55) films. Accordingly, starch:PVA (45:55) films might be considered suitable for packing food predicted for radiation decontamination.

6

Wiedza o rozpuszczalności gazów może uratować życie

Misztal Iwona

Metrologia i Probiernictwo : biuletyn Głównego Urzędu Miar

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2021

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nr 1 (26)

19--22

PL

W artykule opisano prawo Henry'ego dotyczące rozpuszczalności gazów w cieczach w zależności od ciśnienia i temperatury. Znajomość stałej Henry'ego odgrywa bardzo ważną rolę w procesie oddychania, na przykład podczas nurkowania czy przy produkcji napojów gazowanych. Od 200 lat wiedza o rozpuszczalności gazów ratuje ludzkie życie.

EN

The article is about Henry's law on the solubility of gases in liquids depending on pressure and temperature. Knowing the Henry's constant plays a very important role in the breathing process, for example when you are diving or in the production of sodas. For 200 years, knowledge of gas solubility had saved lives.

7

Separation and Immobilization of Vanadium from Industrial Fly Ash as an Insoluble Inorganic Pigmen

Kwolek P., Czubajewski K., Wojnicki M.

Archives of Metallurgy and Materials

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2020

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Vol. 65, iss. 2

901--909

EN

It has been shown that the precipitation of bismuth orthovanadate from a fly ash leachate is a promising method of vanadium recovery. BiVO4 obtained after appropriate heat treatment can be sold as a pigment. The yield of recovery of solubilised vanadium is equal to 68% and the precipitate is free from nickel impurity. The precipitate is insoluble in the solutions with pH ≥ 3. In more acidic media the solubility of precipitate increases with the decreasing pH. The solubility of the precipitate increases also with the increasing concentration of chloride ions.

8

Odzysk wanadu z odpadów przemysłowych - przegląd literatury

Wojnicki Marek, Czubajewski Karol, Kwolek Przemysław

Rudy i Metale Nieżelazne Recykling

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2019

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R. 64, nr 6

17--20

PL

Wanad należy do grupy metali nieżelaznych, stanowiący jeden z podstawowych dodatków do stopów z przeznaczeniem na narzędzia. Obecność wanadu w stopach, znacząco poprawia właściwości mechaniczne. Niestety jego wysoka cena powoduje, iż na rynku pojawiają się fałszywe stopy, które rzekomo mają posiadać wanad lub jego zawartość jest zaniżona względem optymalnych parametrów. Ze względu na jego wysoką cenę, ograniczone źródła naturalne oraz jego toksyczność, koniecznym jest rozsądne i przemyślane zarządzanie zasobami, oraz odpadami zawierającymi ten metal oraz jego sole. W pracy przedstawiono przegląd literatury na temat recyklingu wanadu i jego źródeł antropogenicznych.

EN

Vanadium belongs to the group of non-ferrous metals, which is one of the basic additions to alloys for tools. The presence of vanadium in the alloys, significantly improves mechanical properties. Unfortunately, its high price results in the appearance of false of alloys on the market that allegedly have vanadium. Due to its high price, limited natural sources and its toxicity, it is necessary to have a reasonable and well thought-out management of resources and waste containing this metal and its salts. The following paper presents an overview of the literature on vanadium recycling from its anthropogenic sources.

9

Selective crystallization of gamma glycine for NLO applications using magnesium sulfate (MgSO4) as an additive

Anbu Chudar Azhagan S., Kathiravan V. S.

Materials Science Poland

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2019

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Vol. 37, No. 2

265--279

EN

Crystallization of γ-glycine in the presence of selected concentration (9 g/mL) of tailor-made additive magnesium sulfate heptahydrate salt (MgSO4·7H2O) has been studied at ambient temperature by adopting slow solvent evaporation procedure. The morphological modifications of glycine crystals grown from pure aqueous solutions of glycine and from glycine solutions containing magnesium species in the amount of 0.1 g/mL to 16 g/mL have been investigated thoroughly. The crystalline nature and phase identification of the crystalline material were confirmed by X-ray powder diffraction and SXRD studies. NMR studies revealed the information about the molecular conformation in solution, phase changes, functional groups and chemical environment. FT-IR spectra revealed distinct difference between α and γ-glycine polymorphs in the region around 880 cm−1 to 930 cm−1. The grown γ-glycine crystal had a lower cut-off value at 200 nm and the bandgap value evaluated from the Tauc plot was found to be 5.83 eV. The marked differences between α and γ-polymorphs of glycine were also revealed by DSC thermograms. The mechanical strength of the γ-glycine crystal was studied with the help of Vickers microhardness instrument. Kurtz-powder NLO study proved the generation of second harmonics (i.e. green light emission) in the grown γ-glycine crystal and its efficiency was calculated as 1.44 times better than that of the reference material potassium dihydrogen phosphate.

10

Farmaceutyczne kokryształy antagonistów receptora angiotensyny II

Turek Marika, Bałczewski Piotr

Chemistry, Environment, Biotechnology

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2019

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Vol. 22

13--19

PL

Wieloskładnikowe formy stałe leków cieszą się coraz większym zainteresowaniem ze strony przemysłu farmaceutycznego. Główną ich zaletą jest zdolność do zwiększenia biodostępności leku poprzez poprawę jego właściwości fizykochemicznych, w szczególności rozpuszczalności. Poprawienie rozpuszczalności oraz biodostępności, które są kluczowymi czynnikami determinującymi efektywność substancji czynnej jest istotnym wyzwaniem współczesnej farmacji. Przykładem wieloskładnikowych układów są eutektyki, kompozycje koamorficzne i kokryształy, składające się z substancji czynnej oraz drugiego związku (koformera), który wpływa na poprawę jego rozpuszczalności lub innych właściwości tj. stabilność czy właściwości mechaniczne. Jedną z grup leków o słabej rozpuszczalności w wodzie, a co z tym związane niskiej biodostępności są antagonisty receptora angiotensyny II, które stosowane są w leczeniu nadciśnienia tętniczego. W ostatnich latach podjęto kilka prób połączenia tych związków z innymi cząsteczkami, w celu uzyskania układów o zwiększonej rozpuszczalności. Niniejszy przegląd pokazuje, że przedstawiona strategia jest obiecująca, ponieważ prowadzi do otrzymania kompozycji wieloskładnikowych, które stanowią drogę do otrzymania leków o wielotorowym działaniu.

EN

Multi-ingredient solid forms of drugs are becoming more and more popular in pharmaceutical industry. It is because of their high potential to improve bioavailability of a simple drug by improving its physicochemical properties, mainly solubility. Improvement of the solubility and bioavailability, which are key factors determining drug effectiveness, is an important challenge for modern pharmacy. Examples of multi-component systems are eutectic drugs, co-amorphic compositions and cocrystals, consisting of an active substance and a second compound (coformer), which improves solubility or other properties of the active substance. One of the poorly water-soluble group of drugs are angiotensin II receptor blockers used to treat hypertension. In recent years, several attempts have been made to combine these drugs with other molecules to obtain systems with the enhanced solubility. This review shows that the presented strategy is promising because it leads to multi - component compositions, which are the way to obtain drugs of multidirectional effects.

11

Solubility of Eskisehir thorium/rare earth ores in sulphuric and nitric acids

Kursun I., Tombal T. D., Terzi M.

Physicochemical Problems of Mineral Processing

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2018

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Vol. 54, iss. 2

476--483

EN

Nuclear energy is considered as one of the most important energy resources in the world. Thorium (Th) has a significant potential to be used in electricity production by nuclear energy since its existence is not depended on the presence of another radioactive elements, and it has larger potential reserves than uranium. Bastnaesite ((Ce, La)CO3F) is one of the minerals from which Th can be economically extracted. In this study, solubility of bastnaesite containing ore obtained from Eskisehir, Turkey was investigated by leaching with H2SO4 and HNO3 in terms of leaching performance of thorium and some rare-earth elements (Ce, Nd, La). In this context, representative samples were taken from three different areas in Eskisehir-Kizilcaoren region, and a composite sample was prepared to be used for the leaching experiments. The effects of several parameters such as the solid ratio, leaching time, acid amount and pulp temperature, on dissolution efficiencies of Th, Nd, Ce and La was investigated. The best results were obtained using 3.42 mol/dm3 HNO3, solid–to–liquid ratio of 35%, 120 min leaching time and 60 oC temperature. Under these optimum conditions, the dissolution efficiencies of Th, Ce, Nd, and La were obtained as 94%, 82%, 77% and 70%, respectively.

12

Crystallization, habit modification and control of nucleation of glycine polymorphs from aqueous solutions doped with magnesium sulfate impurity

Azhagan S. A. C., Kathiravan V. S., Priya N. S.

Materials Science Poland

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2018

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Vol. 36, No. 3

483--493

EN

The influence of magnesium sulfate as an additive in the nucleation of α and γ-polymorphs of glycine crystallized from aqueous solutions has been explored for the first time. Based on crystallization experiments, it was concluded that lower concentration of magnesium sulfate, say less than 2 g/mL, favors α-nucleation sites, whereas the optimized concentration of magnesium sulfate impurity to yield γ-nucleation sites is 2 g/mL and above. The nucleation time span (in days), solubility and pH were measured for α- and γ-nucleation sites in the aqueous solutions doped with magnesium sulfate. The glycine polymorphs α- and γ-single crystals were grown by slow solvent evaporation technique at ambient temperature. Crystal habit of glycine polymorphs was investigated and analyzed using goniometry. The unit cell dimensions and space group of the as-grown crystal were identified by single crystal XRD analysis. Both α- and γ-polymorphs of glycine were characterized structurally by powder XRD studies. The percentage of magnesium present in the grown glycine crystals was estimated by inductively coupled plasma optical emission spectrometry elemental analysis (ICP-OES). The nonlinear optical properties of the γ-glycine crystals were examined by Q-switched high energy Nd:YAG laser. The second harmonic generation output efficiency of the as-grown gamma glycine single crystals was computed to be 1.31 times superior than that of the reference material potassium dihydrogen phosphate (KDP).

13

Comparison of the structure of Aβ(1-40) amyloid with the one in complex with polyphenol ε-viniferin glucoside (EVG)

Dułak D., Banach M., Wiśniowski Z., Konieczny L., Roterman I.

Bio-Algorithms and Med-Systems

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2018

|

Vol. 14, no. 2

art. no. 20180008

EN

The analysis of amyloid structures is much easier recently due to the availability of the solid-state nuclear magnetic resonance technique, which allows the determination of the 3D structure of amyloid forms. The amyloidogenic polypeptide Aβ(1-40) (PDB ID 2M9R, 2M9S) in its soluble form is the object of analysis in this paper. The solubility of this polypeptide is reached due to the presence of a complexed ligand: polyphenol ε-viniferin glucoside. Two forms of complexes available in the PDB were taken for analysis with respect to the presence of a hydrophobic core in the 3D structure of these complexes. The idealized hydrophobic core structure assumed to be accordant with the 3D Gauss function distribution was taken as the pattern. The aim of this analysis is the possible further comparison to the structures of the hydrophobic core present in amyloids. It is shown that the discordant (versus the 3D Gauss function) fragments present in amyloids appear accordant in the discussed complexes.

14

Asfalty naturalne – charakterystyka i zastosowanie

Bilski M.

Archiwum Instytutu Inżynierii Lądowej

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2018

|

Nr 27

25--36

PL

W artykule zostały scharakteryzowane i zilustrowane asfalty naturalne według klasyfikacji ze względu na rozpuszczalność w dwusiarczku węgla. Przegląd asfaltów i źródeł ich pozyskiwania ma na celu usystematyzowanie wiedzy na ten temat pod kątem możliwości zastosowania praktycznego. Przedstawiono przykładowe zastosowania w skali przemysłowej omawiany asfaltów naturalnych ze szczególnym uwzględnieniem ich wykorzystywania w budownictwie drogowym.

EN

The article describes and illustrates natural asphalts according to the classification due to the solubility of carbon disulphide. The review of bitumens and the sources of their acquisition aims to systematize knowledge on this subject in terms of practical application. Exemplary applications on an industrial scale, discussed natural asphalts with particular emphasis on their use in road construction have been presented.

15

Asfalty naturalne – charakterystyka i zastosowanie

Bilski M.

Archiwum Instytutu Inżynierii Lądowej

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2018

|

Nr 27

37--48

PL

W artykule zostały scharakteryzowane i zilustrowane asfalty naturalne według klasyfikacji ze względu na rozpuszczalność w dwusiarczku węgla. Przegląd asfaltów i źródeł ich pozyskiwania ma na celu usystematyzowanie wiedzy na ten temat pod kątem możliwości zastosowania praktycznego. Przedstawiono przykładowe zastosowania w skali przemysłowej omawiany asfaltów naturalnych ze szczególnym uwzględnieniem ich wykorzystywania w budownictwie drogowym.

EN

The article describes and illustrates natural asphalts according to the classification due to the solubility of carbon disulphide. The review of bitumens and the sources of their acquisition aims to systematize knowledge on this subject in terms of practical application. Exemplary applications on an industrial scale, discussed natural asphalts with particular emphasis on their use in road construction have been presented.

16

Role of dissolved mineral species in quartz flotation and siderite solubility simulation

Luo X., Wang Y., Ma M., Song S., Zhang Y., Deng J., Liu J.

Physicochemical Problems of Mineral Processing

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2017

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Vol. 53, iss. 2

1241--1254

EN

Quartz is, in most cases, the major gangue mineral found in the iron ores. Although it can be activated by calcium at strong alkaline pH, quartz nevertheless, reports to the concentrate with Fe when the iron ores contain siderite. It causes a poor concentrate grade and separation between quartz and iron minerals. The effect of siderite on reverse anionic flotation of quartz from hematite was studied in our previous investigations. In this work, the effect of siderite dissolution on the quartz recovery in the froth product and the effect of pH, ions and temperature on siderite dissolution were investigated. Microflotation, PHREEQC simulation, solution chemistry calculation and Fourier transform infrared spectroscopy (FTIR) measurements were conducted. It was observed that the dissolved species of siderite exhibited negative impact on quartz flotation. This influence became weak to some extent by either stripping the dissolved species or shortening dissolution time. Siderite was easily dissolved in the presence of calcium ion under strong alkaline conditions and its solubility increased with increasing the calcium ion concentrate and temperature. When the calcium ion was added as an activator of quartz under strong alkaline conditions (pH>9.96), calcium existed mainly in the CaCO3 precipitation form according to the solubility rule in the presence of siderite. This form could adsorb onto quartz surfaces and further the chemical reaction between starch and quartz was monitored by FTIR measurements. This study provides a further supplement for previous study. A potential strategy is suggested that finding a collector used at low temperature or flotation under neutral (or weak alkaline) medium is helpful to the reverse flotation of iron ores containing siderite.

17

Role of Acetone in the Formation of Highly Dispersed Cationic Polystyrene Nanoparticles

Ernawati L., Balgis R., Ogi T., Okuyama K.

Chemical and Process Engineering

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2017

|

Vol. 38, nr 1

5--18

EN

A modified emulsion polymerisation synthesis route for preparing highly dispersed cationic polystyrene (PS) nanoparticles is reported. The combined use of 2,2′-azobis[2-(2-imidazolin- 2-yl)propane] di-hydrochloride (VA-044) as the initiator and acetone/water as the solvent medium afforded successful synthesis of cationic PS particles as small as 31 nm in diameter. A formation mechanism for the preparation of PS nanoparticles was proposed, whereby the occurrence of rapid acetone diffusion caused spontaneous rupture of emulsion droplets into smaller droplets. Additionally, acetone helped to reduce the surface tension and increase the solubility of styrene, thus inhibiting aggregation and coagulation among the particles. In contrast, VA-044 initiator could effectively regulate the stability of the PS nanoparticles including both the surface charge and size. Other reaction parameters i.e. VA-044 concentration and reaction time were examined to establish the optimum polymerisation conditions.

18

Prediction of Gas Solubility in Ionic Liquids Using the Cosmo-Sac Model

Jaschik M., Piech D., Warmuziński K., Jaschik J.

Chemical and Process Engineering

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2017

|

Vol. 38, nr 1

19--30

EN

Thermodynamic principles for the dissolution of gases in ionic liquids (ILs) and the COSMO-SAC model are presented. Extensive experimental data of Henry’s law constants for CO2, N2 and O2 in ionic liquids at temperatures of 280-363 K are compared with numerical predictions to evaluate the accuracy of the COSMO-SAC model. It is found that Henry’s law constants for CO2 are predicted with an average relative deviation of 13%. Both numerical predictions and experimental data reveal that the solubility of carbon dioxide in ILs increases with an increase in the molar mass of ionic liquids, and is visibly more affected by the anion than by the cation. The calculations also show that the highest solubilities are obtained for [Tf2N]ˉ. Thus, the model can be regarded as a useful tool for the screening of ILs that offer the most favourable CO2 solubilities. The predictions of the COSMOSAC model for N2 and O2 in ILs differ from the pertinent experimental data. In its present form the COSMO-SAC model is not suitable for the estimation of N2 and O2 solubilities in ionic liquids.

19

Measurements of Hydrogen Solubility in Nitrobenzene/Aniline Mixtures

Srebniak A., Sobieszuk P., Kraut M., Görke O.

Chemical and Process Engineering

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2017

|

Vol. 38, nr 2

241--248

EN

Measurements of hydrogen solubility in various nitrobenzene-aniline mixtures were conducted in an autoclave reactor with a stirrer and control of temperature. The solubility of hydrogen was measured at 7 different values of temperature (30 °C, 40 °C, 50 °C, 90 °C, 130 °C, 170 °C, 210 °C, respectively), 3 values of stirrer rotation speed (1200 rpm, 1600 rpm, 2000 rpm, respectively) and a range of pressure of 20 ‒ 30 bar. Moreover, pure aniline, pure nitrobenzene and their mixtures with different concentrations were used. In the next step, values of Henry’s constant were calculated. Based on experimental data a dependence of Henry’s constant on temperature for pure aniline and pure nitrobenzene was proposed. Additionally, for each temperature correlations between Henry’s constant and aniline’s concentration in mixture of nitrobenzene-aniline were found.

20

Statistical Optimization and Selective Separation of RDX and HMX Explosives by Using Binary Solvent Mixtures Containing Ethyl Acetate and Water

Damiri S., Pouretedal H. R., Panahi H., Dris A.

Central European Journal of Energetic Materials

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2017

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Vol. 14, no. 2

391--402

EN

The present study introduces the application of a binary solvent of ethyl acetate and water for the selective separation of 1,3,5-trinitroperhydro-1,3,5-triazine (RDX) and octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX). The effect of temperature and weight percent of ethyl acetate in water on the solubility of RDX and HMX over a temperature range of 273.15 K to 363.15 K and 70.0 wt.% to 100.0 wt.% ethyl acetate in water mixtures were modelled and optimized using a central composite design (CCD) and response surface methodology (RSM) in Minitab (ver. 16) software. Multiple regression analysis and analysis of variance (ANOVA) showed that the predicted results were in good agreement with the experimental data. The enthalpies of dissolution and mixing of the materials were determined experimentally from the solubility data. The experimental results showed that the solubility ratio of RDX to HMX can change 6.53- to 16.55-fold, indicating a much lower solubility of HMX in this binary solvent, for a relatively selective separation of RDX and HMX mixtures. Separation experiments under optimized conditions showed that 98.3% of the RDX impurity in HMX was recovered in the first precipitation with an HMX purity of > 99.5% as characterized by high performance liquid chromatography (HPLC).