Giorgi Bibileishvili

The acquisition and use of polymeric membranes with different pore sizes (0.2 μm, 0.45 μm, 0.8 μm) for wine filtration is discussed. The surface topography, productivity and pore dimensions of the obtained membrane samples are studied. It is established that by using filters of membrane samples obtained by wine filtration, it is possible to reduce the initial turbidity of wine from 20.35 NTU to 0.26 -0.6 NTU and to remove yeasts, mold fungi, lactose, vinegar and coliforms in the wine

Polymeric membranes with porous dimensions of 0.005 μm, 0.1 μm, 0,2 μm, 0,45 μm with small surface relief (1-10 nm) are designed and processed to obtain crystal clear, sterile water, while retaining polymer membranes are obtained to remove chemical components. Particles with a molecular mass of 20-10000 daltons. Membrane units equipped with this type of membranes provide high quality drinking water, the obtained product is ecologically clean

The paper presents some results of experimental development of the methodology for determining the molecular mass of components needed to create nanocomposite materials. The data obtained as a result of adjusting the parameters of different concentrations of the order, step, delay time and device are given. The optimal mode parameters of the instrument and the concentration values of the test substance are established to achieve high accuracy of repetition of results

Acetate Cellulose are widely used to produce filtration membranes. To prepare acetate cellulose filtration membranes with desirable properties, the Institute has studied the phase intersection of solutions of various concentrations of acetate cellulose. Dimethylacetamide is used as a solvent for acetate cellulose, however CaCl2 and MgCl2 are used as pore forming agents. During the phase intersection of prepared solutions, water was used as unsolvent. The study of the obtained membrane structure has shown that the existence of calcium chloride in the acetatecellulose solution causes the increase of the amount and size of viscosity and of supramolecular particles. Also in the calcium chloride solutions the process of forming membrane structure is more mild than in magnesium chloride solutions.As a result, membranes with open-porous selective layer are obtained, specific flux of which may be variable with the change of concentration of pore forming lyotropicalts

Today polymer membranes are widely used to filter solution. They constitute 80% of the world production of membranes. The usage of polymers is due to their physical structure and their chemical properties. The Goal of polymer modification is to obtain the membrane with a structure desired for the particular process of filtering.

  Properties of polymer membrane in exploitation depends on polymer, its concentration , composition of the polymer solution, solvent type and the concentration of nonsolvent.

  Cellulose Acetate are often used for preparation of membranes. Their properties are moderate hydrophilic, inertto filtering components of the solution and relatively cheap raw materials.

  The research was conducted on solutions with different concentration of Cellulose Diacetate(5-7%) in DMAc/LiCl for creation of Cellulose Acetate membranes in the Engineering Institute of Membrane Technologies. The study of the process of phase invertion of obtained solutions in different correlation conditions of solvent and nonsolvent revealed that the range of this correlation for Coagulation bath is 0-20%.

  The research was conducted on the automated laboratory instrument created in Institute. The instrument allowed to control the membrane precipitation process by regulating bath temperature and the speed and angle of immersing of the polymer solution in the bath.

  The morphology of the obtained samples is studied by the microscope which is equipped with a digital camera (x5000). The structures of obtained membranes differ. The pore size of some microfiltration membrane is 0,3-0,45µm. 

At the main the development of membrane science and techniques is bonded with membrane materials, creation and processing, which would ensure the separation quality and effectiveness close to biological membranes (maximal wade, selectivity and stability of functional features). Membrane, Catalyst and Hybrid processes for sure, are the processes which would give the possibilities for fast and effective transformation of fundamental researches into high-tech and competitive technologies of the future. Recently, great importance is attached to the use of membranes which are made from polymers for filtration, concentration and fractionation of different liquids. For preparation of membrane are widely used such polymer materials as are: acetylcellulose, the polysulfones, the polioxadiazols and the polyamides.

The goal of researches is the creation of membranes from some mentioned polymer materials (acetylcellulose, the polysulfones, the polioxadiazols, the polyamides) and the studying of some technological parameters, influence on membrane functional groups. During membrane samples, preparation, besides of polymers, was used different modifiers. Dissolve of polymers was occurred in organic solvents, in some cases with addition of metal chlorides.

Was studied the influence of modifiers, concentration on morphology and filtration ability of received membrane samples and the influence on membranes, pore sizes and its scatter range. Were worked out operating parameters of solvents, evaporation from mixtures which are used during the preparation of different membranes

Polyamides(PA) are widely used as high-performance polymers in technical applications due to their combination of outstanding thermal, optical, mechanical and chemical properties The synthetic aromatic polyamides differ from the aliphatic polyamides (nylons) on the highly aromatic nature of the polymer backbone. Both nylons and aromatic polyamides are considered engineering materials. But the aromatic structure of the main chain of the aramids endow this polymers with specialty characteristics making them less sensitive to oxidation higher solvent resistant, and conferring the materials with superior thermal and mechanical resistance, thus being classified as high-performance materials. Both of these polymers can be transformed into flame, cut-resistant and high-tensile strength synthetic fibers, with technological applications in the field of coatings and fillers in the aerospace and armaments industry, in asbestos substitutes, electrical insulation, industrial filters, sport fabrics, gas separation membranes, ion-exchange membranes.

The preparation of asymmetric membranes by the phase-inversion process is a standard technique nowadays. During the study we tested the solvent resistance of the membrane, also investigated the effect of the concentration of polymer solution, the evaporation time of solvent and the temperature of coagulation bath on the membrane performance. The structure of porous membrane is related to the characteristics of the interacting polymer and solvent, components concentration, molecular weight, temperature and storing time in solution. Dimethylsulfoxide (DMSO), dimethylacetamide (DMAC), n-methylpyrrolidone (NMP) and acetone served as solvents for the preparation of the casting solutions. Several additives such as benzene, tetrahydrofure(THF), formamide were used in the casting solution. Water, methanol, glycerol, formic acid and mixtures of these components were used as precipitants the polymer concentration in the casting solution was varied between sand 25wt % polymer.

The mechanical properties and chemical structural changes during the photochemical aging process were studied by using appropriate techniques including infrared spectroscopy (FTIR), X-ray diffraction (XRD), differential scanning calorimetry (DSC), scanning electron microscopy (SEM), atomic force microscopy (AFM) and permeability measurements

Doctoral Thesis Referee

Master Theses Supervisor

Doctoral Thesis Supervisor/Co-supervisor

Scientific editor of monographs in foreign languages

Scientific editor of a monograph in Georgian

Editor-in-Chief of a peer-reviewed or professional journal / proceedings

Review of a scientific professional journal / proceedings

Member of the editorial board of a peer-reviewed scientific or professional journal / proceedings

Participation in a project / grant funded by an international organization

Participation in a project / grant funded from the state budget

Patent authorship

Membership of the Georgian National Academy of Science or Georgian Academy of Agricultural Sciences

Membership of an international professional organization

Membership of the Conference Organizing / Program Committee

National Award / Sectoral Award, Order, Medal, etc.

Honorary title

Monograph

Handbook

Research articles in high impact factor and local Scientific Journals

Publication in Scientific Conference Proceedings Indexed in Web of Science and Scopus