Vladimir N. Zaitsev

Pontifícia Universidade Católica do Rio de Janeiro · Department of Chemistry (QUI)

Organically-modified silica gels bearing mercaptopropyl and ethylenediaminetriacetate groups (SiO2-SH/ED3A) have been used for reduction and subsequent sequestration of Cr(VI) species. The uptake mechanism involves Cr(VI) reduction by thiol groups (SH) and further immobilization of the so-generated Cr(III) species via complexation to the ethylenedi...

Хімія координаційних сполук, що виникла як розділ неорганічної хімії, в даний час є тією ланкою, яка зв’язує такі різні розділи хімії як неорганічна, елементоорганічна, біохімія. Прийшла черга і хімії поверхні. Бурхливий розвиток методів хімічного модифікування поверхні призвів до того, що були одержані сотні видів композиційних матеріалів, поверхн...

Nanodiamonds (NDs) are among the most promising new carbon based materials for biomedical applications and the simultaneous integration of various functions onto NDs is an urgent necessity. A multifunctional nanodiamond based formulation is proposed here. Our strategy relies on orthogonal surface modification using different dopamine anchors. NDs s...

Cited By (since 1996): 5, Export Date: 1 April 2013, Source: Scopus

Recovery of rare earth elements from secondary sources is crucial to promote environmental sustainability and ensure the responsible utilization of natural resources. In this study, we showed a potential application of a silica-based adsorbent with immobilized fragments of aminobis(methylenephosphonic acid) for selective recovery of rare earth elem...

Short-chain aliphatic aldehydes are hazardous environmental pollutants and important biomarkers of various diseases. The development of effective methods for the determination of short-chain aliphatic aldehydes in samples with complex matrices remains an urgent task owing to their harmful effects on living organisms. To choose the optimal method of...

The development of X-ray-absorbing scintillating nanoparticles is of high interest for solving the short penetration depth problem of visible and infrared light in photodynamic therapy (PDT). Thus, these nanoparticles are considered a promising treatment for several types of cancer. Herein, gadolinium oxide nanoparticles doped with europium ions (G...

Herein, we utilized carbon nanodots (R-CNDs) for the electrochemical detection of estrogens in tap and natural water samples and simulated effluents from Swedish waste water treatment plants (WWTPs). R-CNDs were prepared from 2-aminophenol by solvothermal synthesis and used as a modifier for chitosan-based selective membranes. The data obtained fro...

Herein, we utilized carbon nanodots (R-CNDs) for the electrochemical detection of estrogens in tap, natural water samples and simulated effluents from Swedish Waste Water Treatment Plants (WWTPs). R-CNDs were prepared from 2-aminophenol by solvothermal synthesis and used as a modifier for chitosan-based selective membranes. The data obtained from a...

Rational synthesis and simple methodology for the purification of large (35-45 nm in lateral size) and flat (1.0-1.5 nm of height) nitrogen-doped graphene oxide quantum dots (GOQDs) are presented. The methodology allows robust metal-free and acid-free preparation of N-GOQDs with a yield of about 100% and includes hydrothermal treatment of graphene...

Blister agents damage the skin, eyes, mucous membranes and subcutaneous tissues. Other toxic effects may occur after absorption. The response of the Scientific Advisory Board (SAB) of the Organisation for the Prohibition of Chemical Weapons (OPCW) to a request from the OPCW Director-General in 2013 on the status of medical countermeasures and treat...

A set of samples of novel colorized zinc oxide-nanosilica composites was synthesized and analyzed. The color and optical properties are directly dependent on ZnO concentration in the composites. Visible light-driven (λ = 550 nm) catalytic activity on the degradation of pharmaceuticals was tested and indicated that the most active sample with 9 mmol...

Two samples of functionalized mesoporous silica containing anchored anthrylmethylamine groups (SiO₂-Ant) have been prepared by surface assembling (1) and one step silane immobilization (2). Both adsorbents can be attributed to bimodal balanced hydrophobic-hydrophilic adsorbents with loading of anthracene groups about 15-33%. The adsorben...

Two samples of functionalized mesoporous silica containing anchored anthrylmethylamine groups (SiO₂-Ant) have been prepared by surface assembling (1) and one step silane immobilization (2). Both adsorbents can be attributed to bimodal balanced hydrophobic-hydrophilic adsorbents with loading of anthracene groups about 15-33%. The adsorben...

Two samples of functionalized mesoporous silica containing anchored anthrylmethylamine groups (SiO2-Ant) have been prepared by surface assembling (1) and one step silane immobilization (2). Both adsorbents can be attributed to bimodal balanced hydrophobic-hydrophilic adsorbents with loading of anthracene groups about 15-33 %. The adsorbents have be...

Mesoporous Silica with Covalently Immobilized Anthracene as Adsorbent for SPE Recovery of PAHs Pollutants from Highly Lipidic Solutions. Two samples of functionalized mesoporous silica containing anchored anthrylmethylamine groups (SiO 2-Ant) have been prepared by surface assembling (1) and one step silane immobilization (2). Both adsorbents can be...

Two samples of functionalized mesoporous silica containing anchored anthrylmethylamine groups (SiO₂-Ant) have been prepared by surface assembling (1) and one step silane immobilization (2). Both adsorbents can be attributed to bimodal balanced hydrophobic-hydrophilic adsorbents with loading of anthracene groups about 15-33%. The adsorben...

Composition of the immobilized layer plays a crucial role in metal adsorption properties of complexing organo-mineral materials. Ignoring the specific features of chemical reactions on solid surface can lead to a significant deterioration in the target properties of the resulted materials. In this research we demonstrated that rationally designed s...

Because of its high surface area and combination of various functional groups, graphene oxide (GO) is currently one of the most actively studied materials for electroanalytical applications. It is not practical to utilize self-supported GO on its own and thus it is commonly integrated with different supporting carriers. Having a large lateral size,...

Because of high surface area and combination of various functional groups, graphene oxide (GO) is currently one of the most actively studying materials for electroanalytical applications. Self-supported GO is not practical enough to be utilized individually and thus is commonly integrated with different supporting carriers. Having large lateral siz...

A facile and robust synthesis of carbon dots (CDs) emitting blue-light in water without activation and stabilization has been developed by pyrolysis of citric acid (CA) adsorbed in silica gel (SiO2) pores. Effect of the host pore size on luminescent properties of SiO2@CDs nanocomposite as well as water suspension of CDs has been studied. The synthe...

https://doi.org/10.1088/2632-959X/ab7e0d A facile and robust synthesis of carbon dots(CDs) emitting blue-light in water without activation and stabilization has been developed by pyrolysis of citric acid (CA) adsorbed in silica gel(SiO2) pores. Effect of the host pore size on luminescent properties of SiO2@CDs nanocomposite as well as water suspen...

Here we present the first example of excitation-independent blue-emitting carbon dots (iC-dots) obtained by pyrolysis of citric acid (CA) without post-treatment chromatographic separation. To confine the growth and shape of carbon nanoparticles silica gel with immobilized aminopropyl groups (SiO2-NH2) has been used as a nanoreactor. It was demonstr...

Electrochemically-derived well-crystalline mesoporous silicon carbide (pSiC) was used as a host for cobalt nanoparticles to demonstrate superior catalytic performance during the CO hydrogenation according to Fischer-Tropsch. Colloidal Co nanoparticles (9 ± 0.4 nm) were prepared independently using colloidal recipes before incorporating them into pS...

A method of dispersive liquid-liquid microextraction (DLLME) with gas chromatographic separation has been developed and applied for the determination of phthalate esters in water samples and liquid pharmaceuticals. The method allows the determination of various phthalate esters with different polarities, namely: dimethyl phthalate, diethyl phthalat...

Os hidrocarbonetos aromáticos policíclicos (HAPs) são um grupo de mais de 100 produtos químicos com anéis aromáticos. A maioria deles são poluentes orgânicos persistentes. Devido ao acúmulo e natureza lipofílica, o conteúdo de HAPs do tecido dos animais pode ser maior do que o conteúdo de HAPs do solo ou da água onde os vivem. Infelizmente, após o...

The present communication reports the results of application of stable hybrid solid dispersed phase-based (nanodiamonds-nanosilica/titania) suspensions in cytotoxicity tests, using two different cell lines – the mouse sarcoma (J774.G8) and the ovarian carcinoma (OVCAR 8). It is also demonstrated that binary (1 wt% of nanodiamonds and 5 wt% of nanos...

Silica gel with covalently immobilized N-Benzoyl-N-phenylhydroxylamine fragments (SiO2-BPHA) has been successfully prepared using surface assembling approach. The SiO2-BPHA is characterized by FTIR, high-resolution X-ray photoelectron spectroscopy, by SEM and BET measurements, and by elemental and thermogravimetric analysis. It has been demonstrate...

Commercial bulk powder of SiC and SHS-synthesized SiC nanowires were studied. Gold nanoparticles were deposited onto a surface of both samples. Basic properties, such as crystalline structure, phase composition, morphology and photocatalytic activity with the chromatographic analysis of the reaction products, were determined. Obtained silicon carbi...

The Scientific Advisory Board (SAB) of the Organisation for the Prohibition of Chemical Weapons (OPCW) has provided advice on assistance and protection in relation to the Chemical Weapons Convention. In this, the first of several papers describing the SAB's work on this topic, we describe advice given in response to questions from the OPCW Director...

The Scientific Advisory Board (SAB) of the Organisation for the Prohibition of Chemical Weapons (OPCW) has provided advice in relation to the Chemical Weapons Convention on assistance and protection. We present the SAB's response to a request from the OPCW Director-General in 2014 for information on the best practices for preventing and treating th...

Advances across the chemical and biological (life) sciences are increasingly enabled by ideas and tools from sectors outside these disciplines, with information and communication technologies playing a key role across 21 st century scientific development. In the face of rapid technological change, the Organisation for the Prohibition of Chemical We...

The Chemical Weapons Convention (CWC) is an international disarmament treaty that prohibits the development, stockpiling and use of chemical weapons. This treaty has 193 States Parties (nations for which the treaty is binding) and entered into force in 1997. The CWC contains schedules of chemicals that have been associated with chemical warfare pro...

Two samples of novel perspective semiconductor photocatalysts, ZnO-SiO 2 composites, were synthesized using fumed silica (S BET = 300 m 2 /g), carbamide and water solution of zinc acetate. All components were mixed at room temperature in order to obtain 6 (ZnO-SiO 2-1) and 9 (ZnO-SiO 2-2) mmol of ZnO per 1 g of SiO 2. The water was evaporated at 37...

Novel approach to the synthesis of Carbon Dots using silica-based nanoreactor

Silica based adsorbent with immobilized 2,6-pyridinedicarboxylic acid. Adsorption of 17 lanthanide ions simultaneously. Reversible desorption and ICP-MS analysis of lanthanides in the presence of Ba, Fe and Cu ions.

Chromatographic phases with silica immobilized cyanopropyl fragments (CN-phases) are a modern alternative to the common octadecyl phases. They permit reduce separation time of lipophilic compounds when mobile phases with a high content of water is used and thus improve the efficiency of the chromatographic analysis and reduce its cost. However, the...

The article deals with synthesis of bentonite-based materials with covalently immobilized organophosphorus complexing agents: N-methylpropylamino (Bnt-MAPA) and propylaminodi-(Bnt-ADPA) methylene-phosphonic acids. The organo-bentonites were characterized by powder X-ray diffraction, FTIR, and 31 P NMR spectroscopy. It is demonstrated that interlaye...

The Scientific Advisory Board (SAB) of the Organisation for the Prohibition of Chemical Weapons (OPCW) has provided advice on the long-term storage and stability of samples collected in the context of chemical weapons investigations. The information they compiled and reviewed is beneficial to all laboratories that carry out analysis of samples rela...

Совсем недавно произошло горе. Ушел из жизни мой близкий друг и коллега, профессор Юрий Валентинович Холин. Ему было лишь 55 лет… Все должности и заслуги Юрия Валентиновича подробно изложены в официальном некрологе – как-никак, он был первым проректором Харьковского национального университета. Но, мне кажется, что в нашей памяти остается человек, а...

Совсем недавно произошло горе. Умер мой близкий друг и коллега, профессор Юрий Валентинович Холин. Ему было лишь 55 лет… Все должности и заслуги Юрия Валентиновича подробно изложены в официальном некрологе – как-никак, он был первым проректором Харьковского национального университета. Но, мне кажется, что в нашей памяти остается человек, а не его з...

Chromatographic phases with silica immobilized cyanopropyl fragments (CN-phases) are a modern alternative to the common octadecyl phases. They permit reduce separation time of lipophilic compounds when mobile phases with a high content of water is used and thus improve the efficiency of the chromatographic analysis and reduce its cost. However, the...

The electrochemical properties of triamcinolone acetonide on carbon-paste electrodes have been studied. By the cyclic voltammetry method it was revealed that this steroid is irreversibly reduced at a potential from -0.9 to -1.4 V, depending on the solution pH and the potential sweep rate, while an increase in the sweep rate results in a shift of th...

The present review is aimed to familiarize researchers with modified Nguyen-Do method for accurate and thorough analysis on textural structure on the basis of low-temperature nitrogen adsorption-desorption data. A deep analysis offers scope for conceptual foresight of properties of adsorbents, catalysts, active compounds carriers etc. The method is...

The possible approach to improve separation of polyaromatic compounds by using SPE-cartriges based on π-interactions between analytes and adsorbent.

Possibility of using chemically modified silica (CMS) with covalently immobilized sulfonic and ethylenediaminetriacetate (ED3A) groups for the adsorption preconcentration and extraction of tetracycline (TC) from aqueous solutions is studied. The conditions of complex formation by europium(III) ions on the surface of these adsorbents are optimized....

A nanocomposite material with an EDTA counterpart, ethylenediamine triacetate (ED3A), covalently fixed on the surface according to the core–shell technique is obtained in order to develop adsorbents for reversible analytical concentration of heavy-metal ions from solutions. The material is characterized using the methods of IR spectroscopy, X-ray p...

This work is the first report that critically reviews the properties of layered double hydroxides (LDHs) on the level of speciation in the context of water treatment application and dynamic adsorption conditions, as well as the first report to associate these properties with the synthetic methods used for LDH preparation. Increasingly stronger maxi...

Organosilica materials containing λ-carrageenan on their surface are synthesized. The conditions for the immobilization of the polysaccharide, such as phase contact time and pH and concentration of solutions, are optimized. It is shown that the chemisorption of the polysaccharide passes through ion exchange multipoint immobilization, which provides...

Abstract⎯Organosilica materials containing λ-carrageenan on their surface are synthesized. The conditions for the immobilization of the polysaccharide, such as phase contact time and pH and concentration of solutions, are optimized. It is shown that the chemisorption of the polysaccharide passes through ion exchange multipoint immobilization, which...

Porous SiC with uniformly sized 12 nm and 22 nm spherical mesopores was synthesized from nanocomposites of polycarbosilane (PCS) preceramic polymer and xerogels of Ludox® SiO2 nanoparticles as templates. The influence of PCS type (Mw 800 and 2000 Da), PCS:SiO2 ratio, pyrolysis temperature 1200–1400 °C, and addition of Ni complex to the preceramic c...

Получен новые твердофазные экстрагенты на основе кремнезема, модифицированного молекулами - или -каррагинан для селективного извлечения и определения 1,4-диоксана. Оптимизированы экспериментальные условия иммобилизации органических молекул на поверхность SiO2, такие как рН, температура раствора, природа полисахарида и кремнеземной матрицы, концен...

The m-aminophenylarsonic acid (m-APAA) was immobilized onto the silica gel surface with covalently grafted quaternary ammonium groups via ion exchange. The diazotization of ion-bonded m-APAA resulted in a new solid-phase spectrophotometric reagent for detection of 1-naphtol in environmental water samples. The procedure of solid-phase spectrophotome...

Nanodiamond particles (NDs) modified with glycan ligands are revealing themselves to have great promise as new nanomaterials for combating biofilm formation and as promising anti-adhesive scaffolds. Currently, the strategies at hand to formulate glycan-modified NDs (glyco-NDs) are limited to a few reports. We demonstrate herein that the photoinduce...

Nanodiamond particles (NDs) modified with glycan ligands are revealing themselves to have great promise as new nanomaterials for combating biofilm formation and as promising anti-adhesive scaffolds. Currently, the strategies at hand to formulate glycan-modified NDs are limited to some reports. We demonstrate, here, that the photo-induced covalent a...

Gold nanorods (Au NRs) are known for their efficient conversion of photon energy into heat, resulting in hyperthermia and suppression of tumor growths in vitro and in vivo. Au NRs are thus of great promise for photothermal therapy (PTT) of different cancers. From the point of cancer therapy, low laser powers are essential ([less-than-or-equal]1 W c...

For better separation of water-soluble biologically-active compounds by RP-HPLC in mobile phases with high content of water, new C18-type stationary phases with embedded polar groups (EPG-C18) were studied and the results were compared with those obtained on conventional C18 phases. Typical active ingredients of anti-inflammatory syrup, such as: pa...

Silica-based adsorbent was proposed for recovery and analytical pre-concentration of 2,4-dichlorophenoxyacetic acid from aqueous media. It was shown that the recovery of 2,4-D into a sorbent phase is occurred in the form of its ionic associate with cationic surfactants. Good recovery (up to 94%) of 2,4-D is reached in the presence of cetyltrimethyl...