JSCS Vol 66, No. 6
Adobe Acrobat version
|
These articles were
created using Adobe Acrobat and were compressed using WinZip |
To download the latest
|
|
|
To download the text
of the whole issue click here |
To download the latest
|
|
Impresum 
(34 KB - WinZip file); Content of Vol 66, No. 6 (26 KB - pdf file); Instruction for authors (37 KB - pdf file)
J.Serb.Chem.Soc.
66(6)359–365(2001)
UDC 547.822:543.242
JSCS–2863
Original scientific paper
The effect of solvent on the
kinetics of the oxidation of 3-methyl-2,6-diphenyl-piperidin-4-one by
quinolinium fluorochromate in aqueous organic media
KUPPANAGOUNDER P. ELANGO
Department of Chemistry, Gandhigram
Rural Institute-Deemed University, Gandhigram 624 302, India
(Received 4 July 2000,
revised 21 February 2001)
The kinetics of the oxidation of
3-methyl-2,6-diphenyl-piperidin-4-one by quinolinium fluorochromate (QFC) have
been investigated in aqueous solutions of dimethyl sulphoxide, 1,4-dioxane, tert-butanol
and acetone. The influence of the added co-solvent on the reactivity were
analysed in the light of various simple and multiple regression equations, viz
the Laidler-Eyring, Grunwald-Winstein, Swain and Kamlet-Taft equations. The
obtained results showed that the solvation phenomenon plays a dominant role on
the reactivity.
Keywords: kinetics, oxidation, solvent
effect.
To download this article click here (63 KB pdf file)
J.Serb.Chem.Soc.
66(6)367–376(2001)
UDC 576.65:541.182
JSCS–2864
Original scientific paper
Dyeing of hydrophobic fabrics with
disperse dyes
HARI RAGHAV MARADIYA and VITHAL SOMA PATEL*
V.P. and R.P.T.P. Science College,
Vallabh Vidyanagar 388 120, Gujarat State, India,
*Department of Chemistry, Sardar Patel University, Vallabh
Vidyanagar 388 120, Gujarat State, India
(Received 29 January
2001)
A series of disperse dyes has been synthesized
by diazotisation of 2,6-dibromo-4-nitroaniline and coupled with various
N-arylmaleimides. The dyes were characterized by IR spectral studies, visible
absorption spectroscopy and elemental analysis. All the dyes were applied as
disperse dyes on nylon, cellulose triacetate and polyester fabrics. These
dyeswere found to give yellowish orange to deep brown shades with very good
depth, levelness and brightness on different fabrics. The percentage dye bath
exhaustion and fixation on fabrics were found to be very good. The light,
washing, rubbing, perspiration and sublimation fastness properties of the dyed
fabrics were found to be good to excellent.
Keywords: 2,6-dibromo-4-nitroaniline, nylon,
cellulose triacetate, polyester, fixation, fastness, exhaustion.
To download this article click here (65 KB pdf file)
J.Serb.Chem.Soc.
66(6)377–383(2001)
UDC 547.458
JSCS–2865
Original scientific paper
Fine structural analysis of the
fungal polysaccharide pullulan elaborated by Aureobasidium pullulans,
CH-1 strain
DRAGICA JAKOVLJEVIC, MIROSLAV M. VRVIC*, MILANKA RADULOVIC and
MIRJANA HRANISAVLJEVIC-JAKOVLJEVIC*
Institute of Chemistry, Technology
and Metallurgy, Centre for Chemistry, Njego{eva 12, YU-11000 Belgrade and
*Faculty of Chemistry, Univeristy of Belgrade, Studentski trg
12-16, P.O. Box 158, YU-11001 Belgrade, Yugoslavia
(Received 29 December
2000)
The structure of pullulan, the extracellular
a-D-glucan elaborated by the yeast-like fungus Aureobasidium pullulans,
may be described as a linear a-D-glucan consisting of maltotriosyl repeat units
connected terminally by (1->6)-a-D-glucosidic bonds. Occasionally some of
maltotriosyl residues are replaced by higher oligosaccharide units, most
frequently with maltotetraosyl residues. Using the susceptibility of pullulan
CH-1 (obtained from strain CH-1 of Aureobasidium pullulans) to
hydrolysis catalysed by porcine alpha-amylase, the polysaccharide was cleaved
and the fragments obtained fractionated by gel-permeation chromatography. The
heterogenous size of the fragments indicates that there is no apparent regular
distribution of tetrasaccharide units in the pullulan chain. Enzymatic digestion
of pullulan CH-1 using pullulanase, followed by gel-permeation chromatography
of the resulting digest confirmed these results as did preparative paper
chromatography and CI mass spectrometry of the separated components, i.e.,
that maltotetraosyl units (about 7 %) are building units of pullulan CH-1.
Keywords: Aureobasidium pullulans,
polysaccharide, pullulan, amylolysis, pullulanolysis.
To download this article click here (85 KB pdf file)
J.Serb.Chem.Soc. 66(6)385–396(2001)
UDC 549.623.63:541.183
JSCS–2866
Original scientific paper
Sorption characteristics of paper
produced from sepiolite
MIROSLAVA DOJCINOVIC*, MILAN MITROVIC*, MILJENKO MARTIC*, VERA
VUCELIC* and DUSAN VUCELIC*,**
*Institute of General and Physical
Chemistry, Studentski trg 12, P.O. Box 551, YU-11001 Belgrade, and
**Faculty of Physical Chemistry, University of Belgrade,
Studentski trg 16, P.O. Box 138, YU-11001 Belgrade, Yugoslavia
(Received 10 January
2001)
Paper laboratory-produced from sepiolite,
Goles-Serbia was studied to determine its sorption characteristics for nitric
oxides, water vapor, and ammonia. The paper adsorbed high percentages of nitric
oxides and ammonia was stoichiometrically chemisorbed on paper saturated with
NO2 and H2O. Infrared spectroscopy
showed that the sorption of nitric oxides and ammonia does not destroy the
crystal lattice of sepiolite, which was confirmed by XRD-analysis. Sorption of
both nitric oxides and ammonia occurred by zeolitic water inside the structural
channels of sepiolite. Pressure swing adsorption (PSA) or temperature swing
adsorption (TSA) cycles can be repeated many times, in the case of NOx and NH3.
Keywords: ammonia, IR, nitric oxides,
sepiolite, sorption, XRD.
To download this article click here (117 KB pdf file)
J.Serb.Chem.Soc. 66(6)397–401(2001)
UDC 547.458:65
JSCS–2867
Short communication
SHORT COMMUNICATION
Specific
refractive index increments of inulin
GORAN S. NIKOLIC, MILORAD D. CAKIC and LJUBOMIR A. ILIC*
Faculty of Technology, University
of Ni{, Bulevar Oslobodjenja 124, YU-16000 Leskovac and
*Pharmaceutical and Chemical Industry "Zdravlje",
YU-16000 Leskovac, Yugoslavia
(Received 14 July 2000,
revised 28 February 2001)
The specific refractive index increments (dn/dc)
of inulin in water, at 25°C, were measured at different wavelengths (436, 546
and 589 nm) using a BP-differential refractometer. The dn/dc at
the operating wavelength (633 nm) of the laser light scattering photometer was
calculated by an approximate method. This value can be used to determine the
absolute molar mass and the second virial coefficient of inulin by light
scattering photometry.
Keywords: inulin, specific refractive index
increment.
To download this article click here (67 KB pdf file)
J.Serb.Chem.Soc. 66(6)403–409(2001)
UDC 541.183:547.914
JSCS–2868
Note
N O T E
On
the adsorbed mass of polymers on surfaces
GEORGIOS K. STRATOURAS
Kalypsous 15, Akropolis, Nicosia,
Cyprus-2014
(Received 8 December
2000, revised 6 March 2001)
It is shown that for ideal polymers interacting
with a surface via the pseudopotential of a delta function, the number of
contacts between the monomer units and the surface as a function of
concentration cb is a dependence of the form acb/(1–bcb). The architecture of the polymer, the degree
of polymerization, the interaction energy between a monomer unit and the
surface, the area of the surface and the monomer length are embodied in the
parameters a and b. The above dependence of the adsorbed mass of a polymer on
the concentration is confirmed by the experimental results of Takahashi and his
collaborators. For linear polystyrene of molecular weight 134×105,interacting with a chrome plate, the parameters a and b are,
respectively, about equal to (89938/273) ×10-6 m and (–19300/273) m3 kg-1.
Keywords: adsorbed mass, polymer, linear,
cyclic, A-B diblock copolymer.
To download this article click here (73 KB pdf file)
J.Sehem.Soc.
66(6)411–418(2001)
UDC 553.52:548.2
JSCS–2869
Original scientific paper
The growth of sapphire single
crystals
ALEKSANDAR GOLUBOVIC, SLOBODANKA NIKOLIC, STEVAN DJURIC* and
ANDREJA VALCiC**
Institute of Physics, Pregrevica
118, P.O. Box 57, YU-11001 Belgrade,
*Faculty of Mining and Geology, Djusina 7, P.O. Box 162, YU-11000
Belgrade and
**Faculty of Technology and Metallurgy, Karnegijeva 4, YU-11000
Belgrade, Yugoslavia
(Received 8 November
2000, revised 14 March 2001)
Sapphire (Al2O3) single crystals were grown by the Czochralski technique both in
air and argon atmospheres. The conditions for growing sapphire single crystals were
calculated by using a combination of Reynolds and Grashof numbers. Acritical
crystal diameter dc = 20 mm and the critical rate of rotation wc = 20 rpm were calculated from the hydrodynamics of the melt. The
value of the rate of crystal growth was experimentally found to be 3.5 mm/h.
According to our previous experiments, it was confirmed that three hours
exposures to conc. H3PO4 at 593 K was suitable
for chemical polishing. Also, three hours exposure to conc.H3PO4 at 523 K was found to be a suitable etching
solution. The lattice parameters a = 0.47573 nm and c = 1.29893
nm were determined by X-ray powder diffraction. The obtained results are
discussed and compared with published data.
Keywords: Czochralski technique, sapphire,
growth, single crystal, etching.
To download this article click here (106 KB pdf file)
J.Serb.
Chem.Soc. 66 (6)419–427(2001)
UDC 546.19.539.1.08
JSCS–2870
Original scientific paper
A new technique of arsenic
determination based on electrolytic arsine generation and atomic absorption
spectroscopy
MIRJANA M. SEVALJEVIC, SLAVKO V. MENTUS* and NIKOLA J.
MARJANOVIC**
Technological Ecological Center, Petra
Drap{ina 15, Zrenjanin,
*Faculty of Physical Chemistry, University of Belgrade, Studentski
trg 12, YU-11000 Belgrade and
**Faculty of Technology, University of Novi Sad, Cara Lazara 1,
YU-21000 Novi Sad, Yugoslavia
(Received 20 November
2000, revised 14 February 2001)
Amethod for the determination of traces of
arsenic in food has been developed based on electrolytic arsine generation and
atomic absorption spectroscopy detection.
The essence of the method is the addition of
copper and tin salts to the electrolyte solution, enabling a fast and effective
arsine evolution. The advantage of this method lies in the fact that it enables
the simultaneous concentration of heavymetals, such as cadmium and lead, on
cathode. The applicability of themethod was illustrated by determining the
arsenic content in some food samples based on vegetable oils and by comparing
the results with those obtained by the classical technique of chemical
hydriding with sodium tetrahydroborate.
Keywords: arsine generation, atomic
absorption spectroscopy, electrolysis, trace determination, diffusion rate
constants.
To download this article click here (78 KB pdf file)
Copyright & copy; SHD 2001.
Last
Updated June 19, 2001.
For
more information contact: SHD@elab.tmf.bg.ac.yu