The low-temperature sol-gel synthesis of metal-oxide films on polymer substrates and the determination of their optical and dielectric properties

Photoactive, optically transparent heterostructures from silver nanowires and titanium dioxide were obtained by the sol-gel method on the surface of a polyethylene terephthalate film. The characteristics of optical transmission on the wavelength and those of dielectric permittivity, conductivity and dissipation on frequency in the range of 25–1,000,000 Hz were investigated

Certification of Samples in the Bioresource Collection USU 44053 CSBG SB RAS Using Digital Seed Library and Cytological and Genetic Methods

Одним из современных направлений исследований ботанических учреждений является создание биоресурсных коллекций, которые используются для проведения научных экспериментов, прикладных разработок и в образовательном процессе. В Центральном сибирском ботаническом саду СО РАН на базе биоресурсной коллекции USU 44053 проводятся не только научные исследования, но также подготовка бакалавров и магистрантов биологических и сельскохозяйственных специальностей. Цель работы – описание методов, используемых в ЦСБС СО РАН для паспортизации и характеристики объектов биоресурсных коллекций редких и хозяйственно-ценных растений с использованием современных молекулярно-генетических методов и цифровых технологий. Для характеристики коллекционных образцов привлекаются наиболее константные признаки, например морфометрические показатели семян. Микрофотографии цифровой семенотеки позволяют описать морфологические признаки семян и провести статистическую обработку морфометрических параметров с использованием стереомикроскопа Carl Zeiss Stereo Discovery V12 с цифровой камерой высокого разрешения AxioCam MRc‑5 (программное обеспечение AxioVision 4.8). При работе с цифровой семенотекой используются описательно-морфологический и статистический методы обработки данных. К настоящему времени цифровая семенотека ЦСБС насчитывает более 280 образцов, наиболее широко в ней представлены виды семейств Asteraceae, Brassicaceae, Caryophyllaceae, Poaceae, Rosaceae, Solanaceae. Также в учебном процессе используются сведения по морфологии и морфометрии семян видов, входящих в семейства Amaranthaceae, Begoniaceae, Capparaceae, Hydrophyllaсеае, Onagraceae, Paeoniaceae, Papaveraceae, Polemoniaceae, Scrophulariaceae, Verbenaceae. Дополнительной характеристикой являются микрофотографии кариотипов, позволяющие выявить среди представителей внутривидового разнообразия коллекционных образцов хромосомные расы. Для изучения внутри- и межвидовой изменчивости и уточнения таксономического разнообразия, в том числе родственных видов, наиболее удобными маркерами являются запасные белки зрелых семян. Поэтому электрофоретическое исследование состава запасных белков семян является эффективным методом характеристики генотипов растений, входящих в биоресурсные коллекции. Важной характеристикой объектов, входящих в биоресурсные коллекции, является описание присущих им систем размножения, в частности завязывания семян при различных способах опыления. Проверка возможности использования электрофоретического метода с целью идентификации способов семенной репродукции у многолетних злаков трибы Triticeae показала, что у всех видов Elymus L. спектры сестринских зерновок в высокой степени идентичны, что подтверждает представление о самоопылении как основной форме размножения видов этого рода. У Agropyron cristatum (L.) Gaertn., напротив, спектры характеризовались высокой гетерогенностью семян с индивидуального растения, что является показателем перекрестного опыления при наличии множественного аллелизма по генам, контролирующим проламиновые белкиOne of the current trends in research of botanical institutions is the creation of bioresource collections, which are used in scientific experiments, applied research, and education. In the Central Siberian Botanical Garden of the Siberian Branch of the Russian Academy of Sciences (CSBG SB RAS), the bioresource collection USU 44053 is used not only for scientific research, but also for the training of bachelors and masters of biological and agricultural sciences. The purpose of the present work is to describe research methods employed in the CSBG SB RAS to certify resources and characterize specimens in bioresource collections of rare and economically valuable plants using modern molecular genetic approaches and digital technologies. The characterization of collection specimens is based on the most permanent features such as morphometric parameters of seeds. Micrographs of the digital seed library make it possible to describe the morphological features of seeds and carry out statistical processing of morphometric parameters using a Carl Zeiss Stereo Discovery V12 stereomicroscope with an AxioCam MRc‑5 high- resolution digital sensor (AxioVision 4.8 software). In the work with the digital seed library, descriptive- morphological and statistical methods of data processing are used. To date, the digital library of the CSBG has more than 280 accessions, the species of the families Asteraceae, Brassicaceae, Caryophyllaceae, Poaceae, Rosaceae, and Solanaceae being the most diversely represented in it. The data on the morphology and morphometry of seeds of the species belonging to the families Amaranthaceae, Begoniaceae, Capparaceae, Hydrophyllaseae, Onagraceae, Paeoniaceae, Papaveraceae, Polemoniáceae, Scrophulariaceae, and Verbenaceae are also used in the educational process. Additional characterization is provided by microphotographs of karyotypes, which reveal chromosome races among representatives of intraspecific diversity. Storage proteins of mature seeds are the most convenient markers for studying intra- and interspecific variability and specifying taxonomic diversity, for related species as well. Therefore, electrophoretic analysis of the composition of seed storage proteins is an effective method for characterizing plant genotypes included in the bioresource collections. An important characteristic of the samples included in bioresource collections is the description of their reproductive systems, in particular, seed formation under different pollination modes. Electrophoretic analysis used to identify the types of seed reproduction in perennial grasses of the Triticeae tribe showed that in all species of Elymus L., the spectra of sister grains were highly identical, supporting the idea of self-pollination being the main reproduction type of the species of this genus. By contrast, in Agropyron cristatum (L.) Gaertn., the spectra of the seeds of the same plant showed high heterogeneity, indicating cross-pollination and multiple allelism in the genes that control prolamin protein

Microevolutionary relationships between biotypes of

According to descriptions, the Siberian species E. peschkovae and E. confusus differ in the presence or absence of trichomes on lemma and rachilla surfaces only. Two methods were used for study microevolutionary relationships between these species: hybridization of biotypes from different locations and analysis of nucleotide sequences of the low-copy nuclear gene GBSS1. Created and grown hybrids in combinations AMU-8804 × BER-0807 and AMU-8804 × BUK-1109 showed complete seed sterility in two field vegetations. Taking into account wide species areas, 3 hybrids were created between Magadan biotypes from a common habitat in the combination E. confusus MOL1887 × E. peschkovae MOL-1882. The plants showed seed fertility (SF) of 0–3 %. This result does not obscure the possibility to assess SF in the F2 generation and the character of inheritance of diagnostic traits. A comparative study of the GBSS1 gene sequences in accessions was carried out in comparison with clones of reference species. Differentiation of clones by the St2 subgenome in E. confusus, E. peschkovae, E. sibiricus and E. caninus did not reveal a clear relationships between the species. Meanwhile, a certain species specificity for the H1 subgenome was noted, confirming the existence of microevolutionary isolation of these species

Electrorheological Properties of Polydimethylsiloxane/TiO2-Based Composite Elastomers

Electrorheological elastomers based on polydimethylsiloxane filled with hydrated titanium dioxide with a particle size of 100–200 nm were obtained by polymerization of the elastomeric matrix, either in the presence, or in the absence, of an external electric field. The viscoelastic and dielectric properties of the obtained elastomers were compared. Analysis of the storage modulus and loss modulus of the filled elastomers made it possible to reveal the influence of the electric field on the Payne effect in electrorheological elastomers. The elastomer vulcanized in the electric field showed high values of electrorheological sensitivity, 250% for storage modulus and 1100% for loss modulus. It was shown, for the first time, that vulcanization of filled elastomers in the electric field leads to a significant decrease in the degree of crosslinking in the elastomer. This effect should be taken into account in the design of electroactive elastomeric materials

High electrorheological effect in Bi1.8Fe1.2SbO7 suspensions

We report on the first experimental evidence of the electrorheological effect in suspensions of superfin

Enhancing the Thermal Stability of Ionogels: Synthesis and Properties of Triple Ionic Liquid/Halloysite/MCC Ionogels

In this study, an ionic liquid (IL), 1-butyl-3-methylimidazolium acetate, was used to prepare ionogels with microcrystalline cellulose (MCC) and halloysite (Hal). SEM, XRD, TG, DSC, FTIR spectroscopy, conductometry and mechanical tests were used to study the morphology, structure, thermal behaviour and electrophysical and mechanical characteristics of synthesised ionogels. XRD analysis showed a slight decrease in the interlayer space of halloysite in ionogels containing MCC, which may have been associated with the removal of residual water molecules resulting from hydrophilic IL anions and polymer macromolecules. A change in conductivity and glass-transition temperature of the ionic liquid was revealed due to intercalation into halloysite (a confinement effect) and modification with cellulose. For triple IL/Hal/MCC ionogels, the characteristic thermal degradation temperatures were higher than the corresponding values for IL/Hal composites. This indicates that the synthesised IL/Hal/MCC ionogels are characterised by a greater thermal stability than those of IL/Hal systems

Photocatalytic and adsorption properties of TiO2-pillared montmorillonite obtained by hydrothermally activated intercalation of titanium polyhydroxo complexes

We report on a new approach for the synthesis of TiO2-pillared montmorillonite, where the pillars exhibit a high degree of crystallinity (nanocrystals) representing a mixture of anatase and rutile phases. The structures exhibit improved adsorption and photocatalytic activity as a result of hydrothermally activated intercalation of titanium polyhydroxo complexes (i.e., TiCl4 hydrolysis products) in a solution with a concentration close to the sol formation limit. The materials, produced at various annealing temperatures from the intercalated samples, were characterized by infrared spectroscopy, differential scanning calorimetry (DSC)/thermogravimetric analysis (TGA), X-ray diffraction, dynamic light scattering (DLS) measurements, and liquefied nitrogen adsorption/desorption. The photocatalytic activity of the TiO2-pillared materials was studied using the degradation of anionic (methyl orange, MO) and cationic (rhodamine B, RhB) dyes in water under UV irradiation. The combined effect of adsorption and photocatalysis resulted in removal of 100% MO and 97.5% RhB (with an initial concentration of 40 mg/L and a photocatalyst-sorbent concentration of 1 g/L) in about 100 minutes. The produced TiO2-pillared montmorillonite showed increased photocatalytic activity as compared to the commercially available photocatalyst Degussa P25

Surfactant-Switched Positive/Negative Electrorheological Effect in Tungsten Oxide Suspensions

The electrorheological (ER) effect was experimentally observed in dielectric suspensions containing tungsten oxide (WO3) modified with surfactant molecules (sodium dodecyl sulfate (SDS) and dodecylamine (DDA)) in electric fields up to several kilovolts per millimeter. The dielectric properties of WO3 suspensions in silicone oil were analyzed, depending on the frequency of the electric field, in the range from 25 to 106 Hz. Unmodified WO3 suspensions, as well as suspensions modified with sodium dodecyl sulfate, were shown to exhibit a positive electrorheological effect, whereas suspensions modified with dodecylamine demonstrated a negative electrorheological effect. The quantitative characteristics of the negative electrorheological effect in the strain–compression and shear regimes were obtained for the first time. Visualization experiments were performed to see the chain structures formed by WO3 particles modified with sodium dodecyl sulfate, as well as for dynamic electroconvection in electrorheological fluids containing WO3 modified with dodecylamine. The negative electrorheological effect was shown to be associated with the processes of phase separation in the electric field, which led to a multiplicative effect and a strong electroconvection of the suspension at field strengths above 1 kV/mm