Authors:L. Semko, L. Dzyubenko, V. Ogenko, and S. Revo
Composite materials (CM) based on poly(ethylene) (PE) and nanocrystalline nickel (Ni) have been produced. The effect of the
content of nanocrystalline Ni and processes of structure formation of its particles on a melting temperature (Tm), interval of melting, true melting heat (ΔHm), degree of crystallinity (χ) as well as characteristics of CM thermodestruction have been determined by DTA and thermogravimetry
techniques. It was found that these characteristics are changed non-linearly when the content of nanocrystalline Ni increases.
The most efficient influence of Ni on the above mentioned characteristics was observed for its low content (0.01 volume part
of Ni). It was shown that a formation of a branched multifractal cluster of nickel above a percolation threshold favored a
decrease in Tm, ΔHm, χ of filled PE and a majority of thermal characteristics of CM thermodestruction as well.
HDPE based composites were produced with 10-20-30 and 40% composite mass of wood fiber. The coupling agents were epolene and
silane. The thermal behavior of composite samples was analyzed as a function of the coupling agent content, the exposure time
and the wood fibers content by means of differential scanning calorimetry. Calorimetric curves of all samples of first and
second heating shows a similar behavior. Some significant relation has been observed between the exposure time and the degree
of crystallinity for the same percentage of fiber samples. A linear relation between the melting enthalpy average vs. content
in cellulosic fibers is detected. Nevertheless, the fibers non-pretreated with coupling agent show a lower loss of crystallinity
of the HDPE matrix at low wood fiber content (10%). A slight diminution of the melting peak temperature is detected as increasing
the exposure time.
Authors:T. Sopcak, L. Medvecky, T. Zagyva, M. Dzupon, J. Balko, K. Balázsi, and C. Balázsi
adhesion to substrate but also retains high biocompatibility and bioactivity of the Hap coating [ 16 , 17 ]. The PEG-modified hydroxyapatite composite coating exhibited improved binding strength of Hap to the substrate with increased packing density of Hap
Authors:Ali Mohammad, Inamuddin, Arshi Amin, Mu. Naushad, and Gaber E. Eldesoky
Organic–inorganic type composite materials is the latest study of interest in different laboratories for various applications [ 1 – 5 ], owing to their better thermal, chemical, and radiation stabilities compared
Properties and applications of composite ion exchangers developed in this Institute are described. The new sorbents consist of a selective inorganic ion exchanger, e.g., hexacyanoferrate of transition metals or hydrated antimony pentoxide, firmly incorporated into a resin matrix, e.g., phenol-formaldehyde, of various shapes. The composites have proved to be effective adsorbents for radionuclides of cesium, sodium, francium, elements 104 and 105, and some others. The sorbents were successfully tested as filter fillers for radiocesium removal from liquid radioactive wastes and from other solutions encountered in nuclear technology. They were also applied in radiochemical studies and in nuclear activation analysis.
3 to obtain CeO 2 –Al 2 O 3 composite support by using three different methods. Then we prepared Co–Mo catalysts supported on these CeO 2 –Al 2 O 3 supports to study their sulfur-resistant methanation performance. The effect of preparation methods
particles offers the possibility of producing, in a wide temperature range, high-conductivity composites with enhanced thermal stability and improved mechanical performance [ 14 – 16 ]. Considering the feasibility and practicability of RbH 2 PO 4 as fuel
Authors:Maurizio Ferrante, Morena Petrini, Paolo Trentini, Luigi Ciavarelli, and Giuseppe Spoto
The aim of this study has been to evaluate light-curing composites polymerization quality (monomer/polymer) with an halogen
and diode lamp through the thermal analysis (TG-DTA). Samples have been polymerized at 20, 40 and 50 s through a constant
and a soft start polymerization and, subsequently, analyzed by TG-DTA. The TG/DTA analysis shows that different light-curing
times affect the degree of conversion of the composite, since by increasing the curing time the quantity of the monomer that
has not reacted (residual) decreases. The halogen lamp, compared to the diode lamp, produces a lower mass loss at 20 s, while
for 40 and 50 s the results are overlapping. The soft start polymerization (20 s) initially produces a higher mass loss, if
compared to the constant intensity, but, by performing a polymerization for at least 40 s, the results can be overlapped.
The properties of a composite ion exchanger containing potassium nickel ferrocyanide incorporated in silica gel matrix are described. The sorbent was prepared in the form of spherical beads. For the characterisation of the ion exchanger X-ray diffraction, electron microscopy, IR and Mössbauer spectrometry were used. The sorbent was used for the sorption of radiocesium from model solutions as well as from radioactive waste solutions (NPP Jaslovské Bohunice, Slovakia).