This review covers the main problems and basic principles of the use of various membranes in medicine and pharmacy. Developments in the field of sterilizing, bacteriostatic and bactericidal membranes and membranes for pyrogen-free water preparing are considered. An analysis of the scientific literature in this research area are identified. The main ways of development of this area, as well as an analysis of properties of membranes from different manufacturers for use in the medical and pharmaceutical industries are given. Their advantages and disadvantages are considered. It is shown that the main criterion for sterilizing membranes is the pore size, which should be no less than 0.1 microns. The most commonly used materials for sterilizing membranes are PTFE, polyamide and polysulfone. Review of methods for bacteriostatic and bactericidal membranes showed that there are different prospective modification methods of widely used membranes. Examples of some membranes modifications with inorganic and organic substances are considered. It is shown that the most effective modifying agents are chitosan and silver compounds. The mechanism of action of the ions and silver nanoparticles on bacterial cells is shown. A comparison of the effectiveness of distillation and membrane filtration processes for the preparation of water for injection is given. The ultra- and nanofiltration membranes used for pyrogen-free water preparing are described. New data about the properties of charged membranes are given. It is shown that the use of positively charged membranes for pyrogen-free water preparing is perspective, because it works by sieve and adsorption mechanism.
Аннотация: Рассмотрены вопросы управления реактором с применением современных средств промышленной автомати-ки. Представлена принципиальная схема производства, приве-дено ее словесное описание. Дано описание действующей про-граммы на языке Ladder Diagram в среде CoDeSys, реализую-щей алгоритм процесса синтеза полиуретановых предполиме-ров. Представлена визуализация данного технологического процесса.В настоящее время автоматизация химических процессов в производ-стве является важной и актуальной задачей. Внедрение автоматизирован-ной системы управления позволяет не только получить высококачествен-ные продукты, снизить затраты, повысить рентабельность, но и обеспе-чить безвредность производства. Актуальность применения в химическом производстве объясняется сложностью и высокой степенью протекания технологических процессов, а также чувствительностью их к нарушению режима, вредностью условий работы, взрыво-и пожароопасностью пере-рабатываемых веществ и т.д. [1].Существующие системы автоматизации на производствах, построен-ных в конце XX века, часто не могут отвечать современным требованиям автоматизации процессов. С одной стороны, эти системы все еще надежны, Тимакова Ксения Александровна -аспирант кафедры «Химические технологии», ФГБОУ ВПО «ВлГУ», г. Волгоград, e-mail: bka_793@mail.ru; Самойленко Владимир Ва-лерьевич -кандидат технических наук, руководитель Центра управления учебным процес-сом, доцент кафедры электротехники, автоматики и метрологии, ФГБОУ ВО «СтГАУ», г. Ставрополь; Панов Юрий Терентьевич -доктор технических наук, профессор, заведую-щий кафедрой «Химические технологии», ФГБОУ ВПО «ВлГУ», г. Волгоград.
The paper investigates the effect of fillers on the viscosity properties of one-pack polyurethane sealants. It is noted that with the introduction of such mineral fillers as Mikarb, Midol, MTD2 chalk and aluminum hydroxide, the dynamic viscosity of the composition increases uniformly, while when filled with chemically precipitated Calofort SV chalk and MT-GShM talc, an abnormally sharp increase in viscosity is observed. Such an increase in viscosity for Calofort SV is explained by a highly developed surface, in contrast to other fillers. Talc is characterized by a plate-like shape of particles, which leads to a complex orientation of talc particles in the composition and shear difficulties.It was found that a sealant filled with chemically precipitated chalk has more than 100 pts. wt.(parts by weight), per 100 pts. wt. of the prepolymer under the influence of shear forces (at a constant shear rate) during the first 10 minutes of exposure, a sharp decrease in viscosity is observed, which is characteristic of thixotropic compositions, reaching a constant value after 5-10 minutes. After 10 minutes, the thixotropy of the sealant is restored. Talc does not impart thixotropic properties to the sealant composition.
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