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Vol 12, No 3 (2017)
View or download the full issue PDF (Russian)
https://doi.org/10.32362/2410-6593-2017-12-3

CHEMISTRY AND TECHNOLOGY OF ORGANIC SUBSTANCES

5-20 152
Abstract
The aspects of analytical determination of disinfectants derivatives of the phenol series аrе considered. The possibility of codetermination of five derivatives of this series in different disinfectants using the RP-HPLC method in the isocratic mode (UV detection) is shown. Alternatively, the possibilities of the determination with the use of spectrophotometry and GC methods are considered. This study and previous ones showed that the extraction of phenol derivatives by organic solvents from а wide range of disinfectants is feasible only in some cases, preferably with the use of hexane as an extractant. Further spectrophotometry of hexane extracts does not always enable to correctly compensate for the effect of background impurities and requires an additional separation of the components. The literature data and experimental results suggest that it is more efficient to analyze the whole series of disinfectants in isopropanol (sometimes in water) by chromatographic methods, preferably by HPLC. Sample preparation reduces to the solubilization of batches of ready-made disinfectants in isopropanol/water. It is optimal to carry out the chromatographic study using elution with acetonitrile-based systems (for example, СН3СN:Н2O, 60:40) providing the correct determination (λ = 280 nт) of phenol derivatives. The completeness of extraction (if the extraction method is used), as well as the metrology aspects of all the analytical determination is set directly in а laboratory during the realization of procedures of introduction/validation according to the internal documents of the system quality management for the relevant structural unit.
21-27 151
Abstract
The surface behavior and micelle formation of binary and ternary compositions of nonionic surfactants are studied in relation to their cleaning ability with respect to cotton fabric. In mixtures of an alkyl glucoside and oxyethylated alcohol, antagonistic interaction of the components is observed. When a tertiary amine oxide (Oksipav) having a semipolar N→O bond in the molecule is introduced, the formation of mixed micelles occurs. In solutions of mixtures of nonionic surfactants, the critical concentration of micelle formation is reduced, surface activity is increased, the values of maximum adsorption in the surface layers become higher, and the area occupied by the surfactant molecules in a saturated adsorption layer (smol) is reduced as compared to the individual surfactants. Low values of interfacial tension (from 1.2 to 0.88 mJ/m2) in the surfactant solution - toluene system increase the degree of surface cleaning from oil pollution. When cleaning solutions contain mixtures of three nonionic surfactants with different functional groups, synergysm of the wetting, stabilizing, foaming and emulsifying abilities of liquid detergents is provided. Compositions developed on the basis of colloid-chemical criteria are characterized by high removal efficiency with respect to pigment-oil stains from the fabric at pH in the range from 8.8 to 10.5.
28-32 222
Abstract
There is an ever increasing interest in the production and use of bio-based chemical substances for the preparation of polymeric materials designed to obtain children's toys, medical equipment and materials that are in contact with food. Trifunctional esters of citric acid - trialkyl citrates - obtained by esterification of citric acid with aliphatic alcohols C2-C5 are of hazard class 4, good plasticizing ability, compatibility with the polymer, a high flash temperature. Citric acid (global production of 0.85-1 mtpa) is a readily available raw material obtained from the waste of sugar production. The purpose of the study is to develop a model of citric acid esterification with linear alcohols C2-C5 in the presence of homogeneous acidic catalysts for the creation of a domestic technology for the synthesis of plasticizing compositions based on renewable raw materials. The selected catalyst is sulfuric acid. The correlation of reactivity of the aliphatic alcohols C2-C5 with their structure in the esterification of citric acid was studied. Some kinetic parameters (lnk0, Ea) were estimated. Synthesis modes were proposed. The reaction time of the preparation of trialkyl citrates at 96% conversion of citric acid (t = 90 °C) was calculated. Laboratory samples were obtained and tested. Some operational characteristics were determined.

THEORETICAL BASES OF CHEMICAL TECHNOLOGY

33-43 118
Abstract
The dependence of the energy consumption decrease on the different feed composition for the separation of C4+ vapor cracking fraction by means of complex columns implementation is investigated. Distillation sequences consisting of simple columns and partially thermally coupled distillation columns are compared. Cases of direct and indirect separation for all the schemes are considered. In order to reduce capital cost and industrial areas the implementation of dividing wall columns was proposed. These dividing wall columns are the thermodynamic analogs of partially thermally coupled distillation flowsheets. Analysis of temperature, liquid and vapor profiles in the partially thermally coupled distillation sequence revealed that only one column in the original flowsheets requires a structural change when converting it to the partially thermally coupled configuration. It is shown that the complex columns provide energy consumption reduction in the reboilers by 3-60% as compared to conventional distillation schemes.
44-51 123
Abstract
Various options of separation of binary mixtures by combining the processes of fractional crystallization and rectification are considered. The base mixture, depending on its composition, can be initially directed to the rectification stage or to one of the stages of separated components crystallization using the proposed variants. The flow diagrams of integrated heat exchanging systems and schemes involving open and closed type heat pumps under consideration for the determination of ways of reducing energy consumption of the coupled processes were suggested. These solutions enable improving the processes energy efficiency. In addition, the analysis of the effect of the composition and temperature of the initial mixture, the temperature of fractionation at the crystallization stage, the composition of distillates and bottom products on the separation parameters was carried out. It was found that when the initial mixture is fed to the stage of crystallization of one of the components, the energy costs for carrying out the process under consideration are usually lower than when the initial mixture is fed to the rectification stage. It is shown that using a combination of fractional crystallization and rectification processes can significantly expand the possible separation range and improve the technical and economic characteristics of the separation process.

CHEMISTRY AND TECHNOLOGY OF INORGANIC MATERIALS

52-57 175
Abstract
Trivalent gallium compounds are structural analogs of the elements with variable valency in (+3) oxidation state that can be used as cathode materials for electrochemical power devices (iron, vanadium, chromium). Literature data about gallium(III) sulfate are quite scarce. So, we developed a preparation technique for synthesizing Ga2(SO4)3 from Ga(CH3COO)2OH as a starting material. The latter was dissolved in sulfuric acid. Then gallium(III) sulfate hydrate was precipitated under cooling. The obtained precipitate is extremely hygroscopic, and it deliquesces quickly under aerobic ambient conditions. The synthesized gallium(III) sulfate hydrate was dried on the filter and then kept in vacuum at 10-2 torr for two hours to remove traces of water and acetic acid. Gallium(III) sulfate, its intermediates and products of its thermal treatment were studied by differential thermal analysis (DTA) and X-ray diffraction phase analysis. The content of crystallization water in gallium(III) sulfate hydrate was determined, and the composition of the crystallohydrate was established as Ga2(SO4)3·18H2O. (The original X-ray diffraction pattern of the latter is disclosed below in this paper.) The mentioned crystallohydrate lost its water in six steps within 40-350 °С temperature range and formed anhydrous Ga2(SO4)3, which, in turn, decomposed at 700 °С and produced nanocrystalline gallium oxide, Ga2O3. Anhydrous gallium(III) sulfate is slightly hygroscopic, so it should be stored in a desiccator. It was found that propanol-2 (isopropanol) can be used to precipitate gallium(III) sulfate from aqueous sulfuric acid: isopropanol extracts acetic acid and, thus, exhibits salting-out activity. The formed amorphous precipitate partially loses its mass when heated up to 400 °С. However, a single phase Ga2(SO4)3 specimen could not be synthesized by this method. Considering similarities between gallium and indium, it can be assumed that Ga2(SO4)3 precipitate is contaminated by gallium oxosulfate.
58-64 148
Abstract
It was found that it is sufficient to have the values of magnetic susceptibility X of a disperse sample containing ferroparticles to obtain the values of magnetic susceptibility Xч of its particles (particularly, in solving many scientific applied tasks of magnetic control and/or magnetophoresis of such particles). It is important that the values of volume fraction (concentration) γ of the ferroparticles be low (feasible), when simple dependence is acceptable for determining Xч values: Xч = X/γ. The question of the criterion value of γ is considered (it is still a discussion question). This value is up to γ=0.02-0.05 (this is evaluated data existing for a long time) for magnetite samples and even up to γ=0.2-0.25 (circumstantial evidence - by determining the demagnetization factor of disperse ferromagnetic samples). Direct experiments based on the ponderomotive Faraday method are realized with the use of a powder sample within the range of volume fraction γ ≤ 0.3 (for disperse phase - magnetite). The results of the experiments show that the linear part of X(γ) relation ends at γ 0.2. This is confirmed by many other consolidate data obtained by using disperse samples of magnetite (powder, colloid). However, at lower values of γ (γ ≤ 0.02-0.05) “individual” linear relation between X and γ is found as the consolidate data show. Taking into account the proportionality coefficient this relation differs from the previous relation by about 18%. This means that it is appropriate to use X values obtained at γ ≤ 0.02-0.05 for obtaining more accurate values of Xч.

SYNTHESIS AND PROCESSING OF POLYMERS AND POLYMERIC COMPOSITES

65-72 132
Abstract
A composition and method for applying a superhydrophobic composite coating for fabrics based on chemically crosslinked polydimethylsiloxane (PDMS), silica nanoparticles (SiO2 NP), composite nanoparticles with “polystyrene core/silica shell structure” and a fluoroalkylsilane (FAS) were proposed. It is shown that the degree of hydrophobicity and durability of the composition are the functions of NP, PDMS and FAS concentration and their ratios. The optimal concentrations of the components for the formation of a coating with a maximum degree of hydrophobicity (water static and sliding contact angle ≈ 170° and 2°, respectively) were determined. It is established that the developed composition is characterized by prolonged wear resistance to various types of abrasive action, heat treatment, exposure to acids and bases. It was experimentally determined that the observed effects are a consequence of the complex influence of all the constituents of the composition.

MATHEMATICAL METHODS AND INFORMATION SYSTEMS IN CHEMICAL TECHNOLOGY

73-80 106
Abstract
The paper deals with laboratory preclinical studies of the impact of targeted anticancer drugs on the life of A-549 cell cultures of the cancer origin (lung carcinoma). Preclinical studies enable evaluating the effectiveness of targeted therapy drugs, possible contraindications and side effects in order to determine in future the scope of clinical trials and the possibility of performing them. It is proposed to develop information support of preclinical research. In this work the use of functional modeling technology for building a logic-information model in the category of IDEF0 is considered. For detailed elaboration of the model it is necessary to review step-by-step the whole research process. The necessity of creating the information support is connected to the tasks of structuring, storage and processing large amounts of experimental data.
81-86 118
Abstract
The mathematical theory of constructing an integral transformation and the inversion formula for it for the third boundary value problem in a domain with a continuous spectrum of eigenvalues are developed. The method is based on the operational solution of the initial problem with an initial function of general form satisfying the Dirichlet condition and a homogeneous boundary condition of the third kind. On the basis of the obtained relations, a series of analytical solutions of the third boundary value problem for a parabolic equation in various equivalent functional forms is proposed. An integral representation of the analytic solutions of the third boundary-value problem is proposed for the general form of the representation of boundary-value functions in the initial formulation of the problem. The corresponding Green's function is written out.
87-94 129
Abstract
Informational models and control algorithms models for separate functional modules of the pharmaceutical enterprises distribution and supply logistics management are considered in the article. The possibility of such modules management by means of ERP class integrated information systems is shown. Drug procurement management algorithms implemented with the help of ERP and based on the ABC/XYZ analysis methodology, algorithms and informational models for pharmaceutical companies’ logistic system of inventory management in warehouses are proposed. Algorithms, mathematical and information models for the logistic control system of stocks in warehouses with medicinal preparations at pharmaceutical enterprises are proposed. The scheme of the organization of the current incoming control of medicinal preparations in the finished goods warehouse is considered. Functional models are presented in IDEF0 notation for describing management systems based on ERP in distribution and marketing logistics systems in pharmaceutical companies. Examples are given of constructing graphic IDEF0-models, for describing business processes in drug prediction systems (LS) and quality control of incoming products. The analysis of modern ERP-systems is carried out, and their main features and directions of development are revealed, which is the most important step when working in any field of activity.
95-100 110
Abstract
This article describes the development of information systems for modeling a number of polynomial functions based on experimental data, on the basis of which the parameters of thermoelectric coolers are calculated. The input data is entered manually or by uploading files with input data. The calculation is carried out in several stages, including different types of calculations. Some of them are done in parallel and independently of each other. At the first stage, the functions of the measured quantities are calculated by the method of least squares. On their basis the iterative calculation of the main parameters, and also the calculation of a number of additional parameters of the branches are carried out. For convenience in analyzing results, the IS visualizes them in a tabular form and in the form of graphs, giving them in priority of importance for the operator. The results can be exported by copying or automatically in an Excel file.
101-105 144
Abstract
Three statistical criteria were compared on the basis of the sampling of chemical data in the article. When the criteria were compared, the level of significance was taken as equal to 0.05, because this value is most often used in the technical calculations. Evaluation of data on the one-sided outliers of variational series was carried out by using statistical criteria. With the help of Grubbs criterion for checking variation series, outliers were found neither on the right nor on the left. Further examination of the data with the use of three-sigma rule also showed no outliers. The latest statistical criterion used to detect errors was Chauvenet's criterion. When checking the data with this criterion, one error on the right was detected. No outliers were found on the left. According to the generalized results, namely, the vote on the three most statistical criteria, it can be concluded that the variational series belongs to the same general totality. Criteria presented in the article can be applied for the analysis of any data and for making conclusions based on them, if errors were found in the sampling.


ISSN 2410-6593 (Print)
ISSN 2686-7575 (Online)