Synthesis and structure of nanomaterials in the system K2O-Nb2O5-SiO2

The aim of the present work is synthesis of ferroelectric nanomaterials, in the K2O-Nb2O5-SiO2 system via solgel method and studying the processes of formation and structure of the synthesized ferroelectric nanomaterials. The structure of synthesized materials has been studied by means of the following methods: EDS, XRD, FT-IR, SEM and AFM. The results obtained showed that the structure of the investigated compositions does not depend on the niobium content and all the samples keep their amorphous nature at room temperature. The surface structure shows random distribution of different kinds of aggregates with dimensions about 200–500 nm. The presence of a hybrid nanostructure with well-defi ned nanounits having special geometry is clearly observed

STRUCTURAL CHARACTERIZATION OF NANOMATERIALS

Sol-gel method opens new possibilities for synthesis of anomaterials with application in biotechnology and medicine as matrices for immobilization of cells, enzymes and other biomolecules. The main purpose of the present work is to study of the sol-gel synthesis and the structure of silica hybrid nanomaterials containing different quantities of organic component. FT-IR spectra show that in hybrids synthesized by ETMS or MTES strong chemical bonds are observed. The average size of nanoparticles on the sample surface is about 20 - 50 nm and formation of self-organized structures is observed

Structure and properties of innovative silica hybrid materials synthesized for environmental applications

Today, environmental protection is one of the main goals in the strive to preserve the human existence. Development in this area requires invention of new materials, which can reduce the levels of pollution. Hybrid materials are suitable for this purpose, because they combine different desirable properties existing in separate sources into one unique and accessible structure. Most of the commonly used materials for the degradation of different kind of pollutants are based on titanium dioxide, because of its photocatalytic activity under UV irradiation. Innovative silica hybrid materials, containing an organic component (chitosan) and titanium nanoparticles, were successfully synthesized via the sol-gel method and tetraethyl orthosilicate was used as a silica source and network former. Interaction between the chitosan and titanium units, and their influence on the structure of final material, were observed and discussed. A homogeneous structure with an even distribution of titanium and chitosan particles was visible from scanning electron microscopy (SEM) micrographs and the particle size varied between 50 and 150 nm. The formed silica network, characteristic peaks of chitosan and titanium groups and possible interactions between them are observed from Fourier transform infrared (FTIR) spectroscopy spectra and nuclear magnetic resonance (NMR) spectroscopy results. The behaviour of the synthesized silica hybrids after thermal treatment was investigated via differential thermal/thermo-gravimetric analysis (DTA/TG) analysis and the sorption and degradation activities of the obtained hybrid materials were investigated using a solution of methyl orange as model pollutant. The structure and properties of the synthesized silica hybrid materials assert their potential application in environmental remediation due to their photocatalytic degradation and sorption activities against pollutants

Association Of Eosinophilic Fasciitis With Morphea

Эозинофильный фасциит представляет редкое воспалительное заболевание неизвестной этиологии, описанное впервые в 1974 г. Shulman-ом LE. Заболевание проявляется индурацией кожи, соединительной ткани и подлежащей мышечной фасции. Иногда заболевание сопровождается миалгиями, чаще всего в области нижних конечностей. В отличие от склеродермии отсутствуют поражение внутренних органов и Рейно феномен. Устанавливаются гипергаммаглобунемия и эозинофилия. Эозинофильный фасциит часто ассоциируют с гематологическими заболеваниями. Описаны и сочетания с другими аутоиммунными заболеваниями как системная склеродермия, системный lupus eritthematosus, тиреоидит Hashimoto, синдром Sogren, витилиго и др. Появление morphea в ходе эозинофильного фасциита считается редкостью. Авторы наблюдали подобный случай с наличием одновременно двух типов повреждений. Описывается случай 20-илетней пациентки, у которой клиническая картина развивается в течение 6 мес. Начальный отек, а впоследствии и цианотичность, сопровожденные болевыми бляшками в области двух голеней, постепенно переходят в утолщение, уплотнение и гиперпигментации. Почти одновременно с этими жалобами появляются и мелкие коричнево-синюшные бляшки по телу. Диагноз поставлен на базе анамнеза, клинической картины, периферической эозинофилии и гистологической находки с пораженных участков. У пациентки отсутствует системное поражение и сопровождающееся гематологическое или другое заболевание. Терапевтическое овладение и значительное клиническое улучшение достигнуты благодаря применению кортикостероидной терапии, сочетанной с мототрексатом

DEVELOPMENT OF PROTOCOL FOR ANALYSIS OF ACID NITRATING MIXTURE

Technological control of nitration of organic compounds needs data about a composition of acid nitrating mixture before and after nitration. Content of water is a crucial factor for efficiency and safety of the nitration process. The industrial laboratories demands for fast, accurate, precise, low cost and easy to maintain analytical methods. This paper presents the development of a protocol for determination of composition of acid nitrating mixture. The determination of nitric acid is based on redox back titration. Determination of sulfuric acid is based on direct precipitation titration. Water content is determined by calculation. The proposed method showed good accuracy, precision and selectivity, with recoveries (99.80±0.06)% H2SO4 and (98.91±0,80)% HNO3,and total analysis time 20 min.