Biofunctional nanomaterials based on ultra fine silica, protein and aminocarbohydrates

Aim. Investigation of adsorptive interactions of N-acetyl-D-glucosamine (GlcNAc) and N-acetylneuraminic acid (NANA) with ultra fine silica (UFS) modified by protein bovine serum albumin (BSA). Methods. Adsorption, IR-, 1H NMR- and laser Doppler spectroscopy. Results. Conditions for obtaining bionanocomposites (BNC) UFS/GlcNAc, UFS/BSA/GlcNAc and UFS/BSA/NANA are developed. Conclusions. Impellent ability of deconservated bovine gametes decreased in the presence of BNC after adsorptive fastening of protein on UFS surface. The 1H NMR spectroscopy data proved that interaction of GlcNAc with protein was accompanied by essential dehydratation of protein molecules.Цель. Исследование адсорбционных взаимодействий N-ацетил-D-глюкозамина (GlcNAc) и N-ацетилнейраминовой кислоты (N-АНК) с высокодисперсным кремнеземом (ВДК), модифицированным белком бычьим сывороточным альбумином (БСА). Методы. Адсорбция, ИК-, 1Н ЯМР- и лазерно-допплеровская спектроскопия. Результаты. Разработаны условия получения бионанокомпозитов (БНК) ВДК/GlcNAc; ВДК/БСА/GlcNAc и ВДК/БСА/N-АНК. Выводы. Двигательная способность деконсервированных гамет быка снижается в присутствии БНК после адсорбционного закрепления на его поверхности белка. На основе данных 1Н ЯМР-спектроскопии установлено, что взаимодействие GlcNAc с белком сопровождается сильной дегидратацией его молекул.Мета. Дослідження адсорбційних взаємодій N-ацетил-D-глюкозаміну (GlcNAc) та N-ацетилнейрамінової кислоти (N-АНК) з високодисперсним кремнеземом (ВДК), модифікованим білком бичачим сироватковим альбуміном (БСА). Методи. Адсорбція, ІЧ-, 1Н ЯМР- та лазерно-допплерівська спектроскопія. Результати. Розроблено умови отримання біонанокомпозитів (БНК): ВДК/GlcNAc; ВДК/БСА/GlcNAc та ВДК/БСА/N- АНК. Висновки. Здатність до руху деконсервованих гамет бика знижується за присутності БНК після адсорбційного закріплення на його поверхні білка. На основі даних 1Н ЯМР- спектроскопії встановлено, що взаємодія GlcNAc з білком супроводжується сильною дегідратацією його молекул

Кластеризація води в міжчастинковому просторі гідрофобного нанокремнезему АМ-1

The processes occurring in hydrated powders and concentrated suspensions of hydrophobic silica were studied by 1H NMR spectroscopy. It is shown that a mixture of methyl silica and water with a hydration of less than 1 g / g is a wet powder, where water is in the form of submicron clusters filling the interparticle voids of nanosilica, and the interfacial energy is directly proportional to the amount of added water. It was found that at high water concentrations there is a spontaneous increase in the size of water structures, which is accompanied by a sharp decrease in interfacial energy, that may reflect the disappearance of narrow interparticle voids or their filling with air. It is shown that aqueous suspensions of AM-1 are easily mixed with a weakly polar organic solvent chloroform, forming a stable suspension with close the amounts both of water and chloroform. It was revealed that the aqueous suspension of methyl silica has high thixotropic properties, which depend on the time and the magnitude of the applied mechanical loads.Методом 1Н ЯМР спектроскопії було досліджено процеси, що відбуваються в гідратованих порошках і концентрованих суспензіях гідрофобного кремнезему. Показано, що суміш метилкремнезему та води при гідратованості менше 1 г/г являє собою вологий поршок, де вода знаходиться у вигляді субмікронних кластерів, що заповнюють міжчастинкові проміжки нанокремнезему, а міжфазна енергія прямо пропорційна кількості води, що додається. Виявлено, що при великих концентраціях води відбувається спонтанне збільшення розміру водних структур, яке супроводжується різким зменшенням міжфазної енергії, що може відображати зникнення вузьких міжчастинкових зазорів або заповнення їх повітрям. В роботі показано, що водні суспензії АМ-1 легко змішуються із слабополярним органічним розчинником хлороформом, формуючи стійку суспензію, де кількість води та хлороформу може бути близьким. Виявлено, що водна суспензія метилкремнезему має високі тиксотропні властивості, які залежать від часу та від величини прикладених механічних навантажень

Dependence of the Ice Formation Activity of Dioxynaphthalenes, Fluoroglucin and Silver Iodide on the Structure of the Hydrate Shells of Their Crystals

The 1 H NMR spectroscopy of frozen suspensions has been used to investigate the hydrate shells of Agl, fluoroglucin (FG) and dioxynaphthalenes (DON). It has been shown that the ice formation activity (IFA) of the above compounds may be correlated with the inverse thickness of their associated adsorbed water layer and with the free energy of the strongly bound water film. All the compounds studied formed an ice layer at the substance/ice interface in which the mobility of the water molecules has a value which is intermediate between that for water molecules in ice and for adsorbed water molecules. The ratio between the thickness of the layer of ‘mobile’ ice and that of the layer of adsorbed water increased as a function of IFA

1H NMR Chemical Shifts of Adsorbed Molecules on the Carbon Surface

The chemical shifts of water and organic molecules adsorbed on to different types of carbon surfaces (exfoliated graphite, graphite oxide, intercalated graphite, graphitized and non-graphitized activated carbons, carbon black, carbosils) were studied by 1 H NMR spectroscopy. Values of the chemical shift were found to differ in accordance with the structure of the active sites. This is caused by an anisotropic effect associated with condensed aromatic systems. The maximum values of such changes in the chemical shift were observed with slitlike pores formed by graphite clusters in partly graphitized activated carbons. Some such clusters were also identified in carbon black and carbosils. For water, it was found that the chemical shifts also depended on the number of water molecules taking part in the formation of hydrogen-bonded associates

The Influence of Aluminium Concentration on the Hydration of ZSM-5-Type Zeolites in Aqueous Suspensions

The 1 H NMR spectral technique has been applied to the study of samples of ZSM-5-type zeolites. These samples were synthesized using the template procedure and possessed various aluminium concentrations in their crystal lattice. The characteristics of the adsorbed water layers and the values of the free surface energy of the adsorbents were determined. It was established that, for aqueous suspensions of zeolites, the highest concentration of water in the pores was characteristic of the sample containing the lowest amount of aluminium. It was suggested that the amount of water in the pores is determined not so much by the concentration of primary adsorption sites as by the conditions under which the development of water clusters occurs as well as by the competing sorption of water and ambient air

Peculiarities in the Hydration of Cellulose in Air and Water Suspensions as Studied by H NMR Spectroscopy

Bound water layers in hydrated powders and aqueous suspensions of microcrystalline cellulose were investigated by 1 H NMR methods. The characteristics of such layers were calculated and the magnitude of the interfacial energy (γ s ) at the cellulose/water interface in an aqueous environment determined. It was found that the concentration of strongly bound water and the value of γ s were strongly dependent on the concentration of cellulose in suspension. This is probably due to the strong interaction between cellulose particles. At very high suspension concentrations, the concentration of water inside the cellulose filament decreased by more than three-times while the value of γ s decreased from 31 J/g to 9 J/g as a result of surface forces

Structured Water in Porous Solids and Bio-Objects

The interfacial behaviour of water and mixtures of water and organic compounds adsorbed onto carbon and oxide adsorbents and bio-objects (proteins, cells, tissues) was analyzed using 1 H NMR spectroscopy with layer-by-layer freezing-out of the bulk and structured water at 190–280 K and the NMR cryoporometric method based on the Gibbs-Thomson relationship for the freezing point depression for adsorbed liquids

Influence of Structural and Chemical Modification of Silica on its Surface Hydration

It was shown that an unusual structural type of water, which is weakly associated and unfrozen up to 180 K and possessing a proton resonance chemical shift at 1.5 ppm, appears at the patch-wise hydrophilic/hydrophobic interfaces of adsorbents placed in non-polar or weak solvents. Such water can amount to 10 wt% in amount

Surface Properties of Carbonaceous Solids as Examined by H NMR Spectroscopy Using the Bulk Freezing Procedure

It has been established that the type of adsorption sites on the surface of different carbonaceous materials [graphite oxide, thermo-expanded graphite, graphitized and non-graphitized carbons, carbon black, carbonated silicas (Carbosils)] can be determined using a chemical shift in the 1 H NMR spectra of adsorbed test compounds possessing different donor–acceptor properties and polarizability. This is due to the existence of local magnetic anisotropy regions near the carbon surface. The 1 H NMR measurements on adsorbent/adsorbed water/inert solvent interfaces provide an effective procedure for the differentiation of NMR signals from molecules bound with various types of surface sites. Variations in the free energy of water in the adsorption layer of Carbosils having different carbon contents on the silica surface and their free surface energy have been determined from measurements of the temperature dependence of the NMR signal for non-freezing water in the cooling process. A low degree of carbonization for the initial silica surface leads to a drastic increase in the aqueous interlayer thickness structurized by the surface