Publications by authors named "Alexandr V Vinogradov"

Nanocrystalline titanium dioxide (TiO) is a widespread multifunctional and environmentally friendly material that has numerous applications requiring micro-/nanofabrication or thin film deposition. In most cases, the fabrication of titania films can be achieved using cost-efficient solution chemistry combined with various coating or printing techniques. The practical implementation of these methods requires the preparation of a suitable ink with properly adjusted rheological properties.

View Article and Find Full Text PDF

This study is devoted to the development of photonic patterns based on polystyrene spheres (PSS) incorporated in chitosan hydrogels by inkjet printing. Using this method, high-resolution encrypted images that became visible only in high humidity were obtained. Inks based on PSS with carboxylic groups on the surface were made, and their rheological parameters (viscosity, surface tension, and ζ-potential) were optimized according to the Ohnesorge theory.

View Article and Find Full Text PDF

In this study we address a novel design of a planar memristor and investigate its biocompatibility. An experimental prototype of the proposed memristor assembly has been manufactured using a hybrid nanofabrication method, combining sputtering of electrodes, patterning the insulating trenches, and filling them with a memristive substance. To pattern the insulating trenches, we have examined two nanofabrication techniques employing either a focused ion beam or a cantilever tip of an atomic force microscope.

View Article and Find Full Text PDF

Drug delivery systems based on the zeolitic imidazolate framework ZIF-8 have recently attracted viable research interest owing to their capability of decomposing in acidic media and thus performing targeted drug delivery. In vivo realization of this mechanism faces a challenge of relatively slow decomposition rates, even at elevated acidic conditions that are barely achievable in diseased tissues. In this study we propose to combine drug delivery nanocomposites with a semiconductor photocatalytic agent that would be capable of inducing a local pH gradient in response to external electromagnetic radiation.

View Article and Find Full Text PDF

Here, for the first time, we investigated the effects of matrixes with different nature on the stimuli-responsive mechanoluminescence (ML) of incorporated nanoparticles. It turned out that the contraction forces initiated by polymerization process can have compressive effects that differ by orders. This effect was achieved owing to the introduction of ML crystals in an alumina sol-gel system, which has large surface of coagulation contact.

View Article and Find Full Text PDF

In this study, we present a new concept for the simple visual detection of nano-scale objects in solutions. To achieve this goal, we developed chromogen-free interference-based sensors that provided a color visible reaction directly after the interaction of the analyte with the substrate. The effect is based on the strong optical interference occurring at the interface between the inkjet printed sol-gel titania film (a layer with high refractive index) and the adsorbed nano-sized objects (layer with low refractive index), which can be detected even with the naked eye.

View Article and Find Full Text PDF

We describe the synthesis and properties of a new composite material based on heparin and MIL-101(Fe) metal-organic framework. The intrinsic instability of MIL-101(Fe) towards hydrolysis enables binding of heparin molecules to the framework structure as is evidenced by DFT calculations and adsorption experiments. The de novo formed heparin-MOF composites showed good biocompatibility in in vitro and demonstrated pronounced anticoagulant activity.

View Article and Find Full Text PDF

We report on a new approach for the synthesis of TiO-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.

View Article and Find Full Text PDF

We have demonstrated for the first time an inkjet fabrication of highly efficient luminescent structures based on Eu-doped ZrO nanocrystals (3.4 ± 0.3 nm), with a refractive index close to the one of the bulk materials.

View Article and Find Full Text PDF

Synergistic combination of organic and inorganic nature in van der Waals metal-organic frameworks supports different types of robust excitons that can be effectively and independently manipulated by light at room temperature, and opens new concepts for all-optical data processing and storage.

View Article and Find Full Text PDF

In this paper we for the first time report a reversible sol-gel-sol approach to obtain optical enzymatic biosensors with improved enzyme stability and good sensitivity by using desktop inkjet printing. The developed technique is based on the bio-inorganic inks allowing for a sol-gel-sol transition of the inorganic matrix: from liquid ink to a solid alumina matrix with entrapped enzymes and a subsequent color response due to the enzymatic reaction upon the resuspension of the matrix. This approach improves the stability of the enzymes entrapped in the porous inorganic matrix, and at the same time maintains a high sensitivity of the biomolecules, whose facile release is ensured by the gel-sol transition.

View Article and Find Full Text PDF

This paper describes a practical approach for the fabrication of highly visible interference color images using sol-gel ink technique and a common desktop inkjet printer. We show the potential of titania-boehmite inks for the production of optical heterostructures on various surfaces, which after drying on air produce optical solid layers with low and high refractive index. The optical properties of the surface heterostructures were adjusted following the principles of antireflection coating resulting in the enhancement of the interference color optical visibility of the prints by as much as 32%.

View Article and Find Full Text PDF

Color printing technology is developing rapidly; in less than 40 years, it moved from dot matrix printers with an ink-soaked cloth ribbon to 3D printers used to make three-dimensional color objects. Nevertheless, what remained unchanged over this time is the fact that in each case, dye inks (CMYK or RGB color schemes) were exclusively used for coloring, which inevitably limits the technological possibilities and color reproduction. As a next step in printing color images and storing information, we propose the technology of producing optical nanostructures.

View Article and Find Full Text PDF

Herein, we report a new method for the crystal growth of two Zn-based MOFs at room temperature (known MOF-5 and a new modification of [{Zn2(TBAPy)(H2O)2}·3.5DEF]n (1)) by employing slow diffusion conditions. Employing both Zn-based MOFs with different pore morphology made it possible to discover an anomalous adsorption of L-histidine in of up to 24.

View Article and Find Full Text PDF

A single-step hydrothermal synthesis of a TiO2-Mil-125 composite was applied for the first time to produce a depleted perovskite/TiO2-MOF heterojunction solar cell with 6.4% power conversion efficiency (PCE), characterized by durable stability in air.

View Article and Find Full Text PDF

This paper reports an original technique that provides a highly pure crystalline sol of titania with controllable particle size by ultrasonic activation of the hydrolysis products of titanium isopropoxide in an aqueous medium at a near-neutral pH, which is potentially promising in impurity-sensitive electronics and biochemical engineering. Optimal conditions (H2O/TIP ratio, sonication time, etc.) for preparation of stable nanocrystalline titania sol were adopted.

View Article and Find Full Text PDF