Bucharest, Romania
Bucharest, Romania

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Dimonie D.,ICECHIM Bucharest | Radovici C.,ICECHIM Bucharest | Trandafir I.,ICECHIM Bucharest | Pop S.F.,ICECHIM Bucharest | And 6 more authors.
Revue Roumaine de Chimie | Year: 2011

The structure and properties of the bio-hybrids based on starch and PVOH obtained with MMT conditioned before melt processing into a good plasticizer depends on the conditioning sequence characteristics. A small influence on the silicate morphology can be a sign that the silicate was only hydrated by water and it is not yet dispersed into water. The stirring of multilayered silicate into a good starch and polyvinyl alcohol plasticizer in a special mechanical sequence is a good method to increase the silicate exfoliation.


Dimonie D.,ICECHIM Bucharest | Kelnar I.,Czech Institute of Macromolecular Chemical | Socoteanu R.,Romanian Academy of Sciences | Darie R.N.,Petru Poni Institute of Macromolecular Chemistry | And 5 more authors.
Materiale Plastice | Year: 2010

The paper presents the effects of the miscibility and of the micro-structure on the surface defects of some bio-hybrides based on starch, polyvinyl alcohol (PVOH) and multilayered silicates. At macroscopic level (100μ) the studied starch bio-hybrids seem to be compact materials. If these materials are analysed at a microscopic level (10 μ) depending on their type surface defects like voids, cracks and fractures can be observed. These defects are not a consequence of a poor miscibility, even in case of bio-hybrids that contain untreated silicate. These defects appear because of the bio-hybrids micro-structure. As the new bio - hybrids are probably disorderly ones, it can be estimated that the surface defects appear as a consequence of a poor distribution of the swollen silicate tectoids into the polymeric matrix, possibly as a consequence of the improper melt processing conditions.


Ion R.-M.,ICECHIM Bucharest | Ion R.-M.,University Valahia of Targoviste | Turcanu-Carutiu D.,Ovidius University | Fierascu R.-C.,ICECHIM Bucharest | And 6 more authors.
Applied Surface Science | Year: 2015

The development of new composition for surface conservation of some architectural monuments represents now an important research topic. The Basarabi-Murfatlar Ensemble, recognized as the first religious monument from mediaeval Dobrogea (Romania) (from 9th to 11th century), is one of the most impressive archaeological sites of Europe. This ensemble is built from amorphous calcium carbonate, very sensitive to humidity, frost, salts, etc. The aim of this paper is to test on chalk stone samples a new consolidant - hydroxyapatite (HAp) mixed with calcium oxalate trihydrate (caoxite) (COT). Some specific techniques for evaluation its impact on chalk stone surface are used, as follows: petrographical and physical-chemical techniques: SEM, OM, ICP-AES, TGA, FTIR and Raman spectroscopy, chromatic parameters changes, the accelerated weathering tests: heating, freeze-thaw, and their effects on porosity and capillary water uptake by the chalk surface. All these have been evaluated before and after treatment with COT-HAp, putting into evidence the effect of the new composition on the chalk stone surface. HAp induces COT stabilization, and their joint composition can bind weathered stone blocks providing a substantial reinforcement of chalk surface. © 2015 Elsevier B.V.


Poinescu A.A.,University Valahia of Targoviste | Ion R.M.,University Valahia of Targoviste | Van Staden R.-I.,National Institute of R and D for Electrochemistry and Condensed Matter | Van Staden J.F.,National Institute of R and D for Electrochemistry and Condensed Matter | Ghiurea M.,ICECHIM Bucharest
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2010

It is well-known that hydroxyapatite have multiple applications in tissue engineering due to compositional similarities with bone tissue. In this work, hydroxyapatite powders obtained by modified chemical precipitation route, has been investigated by AMF and SEM analysis grain size, X-ray diffraction and infra-red spectroscopy. The particle size of hydroxyapatite was observed to be very fine, uniform, around 50-60 nm. SEM observation of the HA coatings showed the presence of nano-sized needles, with a significant level of agglomeration. The infrared analysis show the characteristic peaks of absorbed water, hydroxyl, phosphate and carbonate species. The XRD pattern clearly indicated the crystallites responsible for the Bragg reflection of the (002) and (003) planes are useful for size determination by Sherrer relationship (around 68 nm). © 2010 SPIE.


Dimonie D.,ICECHIM Bucharest | Coserea R.M.,ICECHIM Bucharest | Andrei F.,Science Rompetrol Rafinare SA
Leather and Footwear Journal | Year: 2010

Trademark means a way to promote a product on the market, to conquer new sectors of the market, to keep the loyal clients of the company and to create a national and international brand. A mark can be opposed to another mark that belongs to a challenger, only after the registration at OSIM. The deposit confers to the first applicant a temporary right for goods and services requested in the application, that allows him to fight counterfeits or illegal imitations. Thus, the financial efforts for promotion of the owner of the mark to make his products public, cannot be used by challengers in an unfair way. The registered mark becomes an active element that can be evaluated or commercialized.


Mihailescu M.,Polytechnic University of Bucharest | Gabor A.R.,ICECHIM Bucharest
Romanian Reports of Physics | Year: 2011

The holographic interferometry technique associated with the fringe processing in the Fourier plane permits the real-time monitoring due to digital recording with great resolution and is used to detect the optical path length variations in a transparent media and consequently the temporal and spatial distribution of the refractive index in liquid solutions with concentration gradient. A new method based on the auto-correlation coefficients, the convolution and shift theorems is introduced to visualize the displacement of the fringe pattern in regions with different concentration in isotropic and anisotropic conditions. The experimental results have been used in the diffusion process modeling and to calculate the diffusion coefficient of the potassium dihydrogen phosphate in water.


Dimonie D.,ICECHIM Bucharest | Radu S.,Academy Institute of Chemistry and Physics | Doncea S.,ICECHIM Bucharest | Pop F.S.,ICECHIM Bucharest | And 3 more authors.
E-Polymers | Year: 2011

Based on the FTIR spectral changes, the miscibility of some nanocomposites based on starch, polyvinyl alcohol and treated multilayered silicate, was qualitatively estimated. The FTIR spectroscopy provide evident gross/small spectral changes as well as appreciable spectral shifts mainly in those spectral range that defines hydroxyl O-H vibrations (3600-3000 cm-1), water absorbtion (1800-1500 cm-1), the morphological order degree and the interaction with multilayered silicate and (1192-950 cm-1). Based on the observed spectral modifications it can be estimate that high miscibility do exist between the components of the studied nanocomposites.


Dimonie D.,ICECHIM Bucharest | Dimonie M.,ICECHIM Bucharest | Iliescu S.,Science Rompetrol Rafinare SA | Pavel M.,Science Rompetrol Rafinare SA | And 5 more authors.
Journal of Elastomers and Plastics | Year: 2012

Bitumen properties may be successfully modified if the polymeric modifiers have the ability to control the elastic and plastic properties within wide temperature ranges of -30/-40°C to +45/+60°C. The article presents a study on the ability of two thermoplastic elastomers, thermoplastic block co-polymer styrene-styrene butadiene (SBS) and the co-polymer ethylene-vinyl acetate (EVA), to be used in obtaining polymer bitumen composites with controlled properties.The elastic and plastic properties of the bitumen composites can be more easily controlled if these composites are modified with SBS. This thermoplastic elastomer is characterized by an optimum ratio between soft domains of amorphous polybutadiene and rigid ones of those represented by the thermoplastic blocks of polystyrene. © 2012 SAGE Publications.

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