Journal of the University of Chemical Technology and Metallurgy, 39, Book 2, 2004
Journal of the University of Chemical Technology and Metallurgy, 39, Book 2, 2004
EDITOR-IN- CHIEF
Prof. DSc Rumen I. Dimitrov
Department of Fundamentals of ChemicalTechnology,
Tel: (+ 359 2) 62 54 485
University of Chemical Technology and Metallurgy,
8 Kl. Ohridski ., 1756 Sofia, Bulgaria
E-mail: rumen@uctm.eduChapters:
Review
PLASMACHEMICAL NANOTECHNOLOGIES IN CATALYSIS
G. Vissokov
Chemical Technology
SYNTHESIS OF PYRROLE- AND PYRROLYLCARBOXYLIC HYDRAZIDES AND THEIR DITHIOCARBAZATES
A. Bijev, P. Prodanova
ON THE SYNTHESIS AND APPLICATION OF SOME NEW METALLIZED BIFUNCTIONAL REACTIVE AZO DYES AND THEIR NON-METALLIZED ANALOGS
P. Miladinova, T. Konstantinova
PRODUCTION OF LOW MOLECULAR PHENOLIC COMPOUNDS FROM TECHNICAL HYDROLYSIS LIGNIN
S. Nenkova, T. Vasileva, K. Stanulov
POSSIBILITIES FOR CREATING POLYAMIDE TEXTILE MATERIALS WITH HAEMOSTATIC AND ANTIMICROBIAL PROPERTIES FOR MEDICAL APPLICATION
A. Georgieva1, B. Alexandrov1, Chr. Ivanova1, J. Topalov2, S. Nikolov2
ADSORPTION OF PHENOL FROM WASTEWATERS OVER WOOD SAWDUST, BARKS AND TECHNICAL HYDROLYSIS LIGNIN
S. Nenkova, L. Radev
STUDY OF THE EFFECT OF GAMMA RAYS TREATMENT ON LIPID PEROXIDATION OF NON-PERISHABLE RAW-DRIED SALAMI
N. Kaloyanov 1, S. Brachkova 2
ELECTROCHEMICAL PROTECTION OF INTERNAL SURFACES THROUGH ALUMINIUM ANODE DISSOLUTION
D. Ionova1, L. Fachikov2
Chemistry
USE OF COMPETITIVE ION EXCHANGE FOR INTERACTION OF BENTONITE WITH Cr (III) CHELATE
M. Atanassova, E. Kashchieva, I. Dukov
Mathematics, Physics
ANALYSIS OF THE SOLUTION OF THE SUPPORT PROBLEM IN THE OPTIMIZATION ALGORITHM FOR DYNAMIC SYSTEMS WITH TERMINAL CONSTRAINTS IN A CLASS OF INERTIAL CONTROLS
L. Dimitrova
OPTICAL ABSORPTION EDGE IN GaP AFTER LASER DOPING WITH Zn
D. Demireva
EFFECTS OF SOME PARAMETRIC VARIATIONS ON THE OPTICAL PROPERTIES OF CHEMICAL BATH DEPOSITED BiClO THIN FILMS
F. I. Ezema
PLASMACHEMICAL NANOTECHNOLOGIES IN CATALYSIS
(Review)
G. Vissokov
University of Chemical Technology and Metallurgy,
8 Kl. Ohridski, 1756 Sofia, Bulgaria
E-mail: vissokov@abv.bg
Received 25 May 2004
Accepted 15 June 2004
Investigations and author,s considerations about plasmachemical preparation, regeneration and activation of nanostructured catalysts in low-temperature plasma (electric-arc torch, high frequency and other discharges) have been summarized in this review. The four main trends in the plasmachemical preparation of catalysts are described: 1) Plasmachemical synthesis and activation of catalysts in the condensed phase, 2) Plasma-assisted deposition of catalytically active compounds and composites on various carriers, 3) Plasmachemical regeneration of spent catalysts, and 4) Activation of catalytic processes in a plasma conditions. The theoretical basis and advantages of plasma-chemical synthesis and regeneration of spent catalysts are discussed. And finally the investigations on plasma modification of catalysts have been reviewed as a new direction in this area.
It is pointed out that the high catalytic activity and thermal stability of plasma-chemical prepared, modified and regenerated catalysts make them a potential competitor to their industrial analogies
Keywords: catalysts, plasmachemical–synthesis, regeneration, activation, supported catalysts, modification.
SYNTHESIS OF PYRROLE- AND PYRROLYLCARBOXYLIC HYDRAZIDES AND THEIR DITHIOCARBAZATES
A. Bijev, P. Prodanova
University of Chemical Technology and Metallurgy,
8 Kl. Ohridski, 1756 Sofia, Bulgaria
E-mail: a.bijev@uctm.edu
Received 26 February 2004
Accepted 17 May 2004
Three new carbohydrazides, containing pyrrole cycle (1-hydrazinocarbonylmethyl-2,4-dimethyl-5-phenyl-1H-pyrrole-3-carboxylic acid ethyl ester; 1-(2-hydrazinocarbonyl-ethyl)-5-(4-methoxy-phenyl)-2-methyl-1H-pyrrole-3-carboxylic acid ethyl ester and 5-(4-chloro-phenyl)-1-hydrazinocarbonylmethyl-2-methyl-1H-pyrrole-3-carboxylic acid ethyl ester), were synthesized and together with five known hydrazides converted to the relevant dithiocarbazates by reaction with carbondisulfide in alkali media at ambient temperature.
The new eleven compounds were proved by 1H-NMR and IR-spectra. Spectral interpretations and TLC-characteristics are represented.
The new products may be useful as versatile intermediates in the synthesis of pharmacologically significant hydrazones, 4H-1,2,4-triazoles and 1,3,4-thiadiazoles, containing pyrrole cycle.
Keywords: pyrroles, heterocycles, hydrazones, condensation, synthetic methods.
ON THE SYNTHESIS AND APPLICATION OF SOME NEW METALLIZED BIFUNCTIONAL REACTIVE AZO DYES AND THEIR NON-METALLIZED ANALOGS
P. Miladinova, T. Konstantinova
University of Chemical Technology and Metallurgy,
8 Kl. Ohridski, 1756 Sofia, Bulgaria
E-mail: ppolya@uctm.edu
Received 22 Marchy 2004
Accepted 30 April 2004
The synthesis of twelve bifunctional reactive monochloro triazine dyes (eight metallized and four non-metallized dyes) and their intermediates were investigated. Two monochlorotriazine reactive dyes, a blue and a black one, with practical application as basic chromophores were chosen. Thin-layer chromatography (TLC) was used to monitor the synthesis. Cotton and wool fabrics were dyed and their colourimetric characteristics were measured. The copolymerization of the dyes with acrylamide (ACA) was studied. Copolymers with an intense colour stable to solvent extraction presenting a possibility for an environmentally more tolerant application of the dyes were obtained.
Keywords: bifunctional metallized reactive triazine dyes, polymerisable dyes, inherently colored polymers of acrylamide.
PRODUCTION OF LOW MOLECULAR PHENOLIC COMPOUNDS FROM TECHNICAL HYDROLYSIS LIGNIN
S. Nenkova, T. Vasileva, K. Stanulov
University of Chemical Technology and Metallurgy,
8 Kl. Ohridski, 1756 Sofia, Bulgaria
E-mail: nenkova@mail.bg
Received 19 April 2004
Accepted 30 May 2004
Alkaline depolymerization of technical hydrolysis lignin (THL) has been carried out at temperature of 180°C for 4 and 6 hours with depolymerizing agent 5 % aqueous solution of NaOH at hydromodule 1:8. By means of coupled Gas Chromatography/Mass Spectrometry (GC/MS) extracted with toluene low molecular products have been identified: benzaldehyde, 2-methoxyphenol (guaiacol), 2,6-dimethoxyphenol (syringol), vanillin, etc. During the 6 hour depolymerization a bigger quantity of low molecular phenolic products is obtained from the aqueous phase and precipitated activated lignin, liberated from the resistant to hydrolysis polysaccharides, possessing higher reactivity than the initial lignin. This process increases the possibilities for utilizing the waste technical hydrolysis lignin.
The obtained low molecular phenolic compounds can be used for production of antiknock and antioxidant additives to fuels.
Keywords: hydrolysis lignin, depolymerization, low molecular phenolic compounds.
POSSIBILITIES FOR CREATING POLYAMIDE TEXTILE MATERIALS WITH HAEMOSTATIC AND ANTIMICROBIAL PROPERTIES FOR MEDICAL APPLICATION
A. Georgieva1, B. Alexandrov1, Chr. Ivanova1, J. Topalov2, S. Nikolov2
1University of Chemical Technology and Metallurgy,
8 Kl. Ohridski, 1756 Sofia, Bulgaria
E-mail: angi@mail.bg
2Military Medical Academy – Sofia
Received 11 February 2004
Accepted 15 March 2004
Calcium chloride is proposed as an agent, imparting haemostatic properties to polyamide textile materials, intended for medical application in the shape of surgical sutures. A methodology has been developed for combined two-bath haemostatic and antimicrobial treatment of the materials with Calcium chloride and derivatives of 8-oxyquinoline respectively, in different sequence under the selected optimal conditions.
A comparative evaluation of the antimicrobial effect of the treated samples has been done by the Agar-diffusion method and by the method of microbial impermeability. The haemostatic effect has been studied by the method of spontaneous coagulation of venous blood. Very good antimicrobial effect and good haemostatic effect have been proved.
Keywords: haemostatic agents, antimicrobial agents, special treatments of textile materials, haemostatic effect, antimicrobial effect.
ADSORPTION OF PHENOL FROM WASTEWATERS OVER WOOD SAWDUST, BARKS AND TECHNICAL HYDROLYSIS LIGNIN
S. Nenkova, L. Radev
University of Chemical Technology and Metallurgy,
8 Kl. Ohridski, 1756 Sofia, Bulgaria
E-mail: nenkova@uctm.edu
Received 16 March 2004
Accepted 17 May 2004
The basic results of the investigation have enabled the autors to create the idea that wood sawdust, barks and technical hydrolysis lignin (THL) can be used as good adsorbents for cleaning waters from dissolved in them phenol.
The adsorption ability of investigated adsorbents decreases in the following order: sawdust>wood barks>THL.
Keywords: adsorption, phenol, sawdust, wood barks, THL.
STUDY OF THE EFFECT OF GAMMA RAYS TREATMENT ON LIPID PEROXIDATION OF NON-PERISHABLE RAW-DRIED SALAMI
N. Kaloyanov 1, S. Brachkova 2
1University of Chemical Technology and Metallurgy,
8 Kl. Ohridski, 1756 Sofia, Bulgaria
E-mail: mikkaloyanov@hotmail.com
2 National Diagnostic and Research Veterinary Institute,
15 Pencho Slaveikov blvd., 1606 Sofia, Bulgaria
Received 11 March 2004
Accepted 9 June 2004
Decontamination of non-perishable meat products from pathogenic microorga-nisms is possible only through the method of cold sterilisation in which changes of their lipids are of essential importance.
The effect of gamma rays treatment on oxidation processes running in the lipid component of non-perishable raw-dried salami of cut meat pieces (“Lukanka”) has been studied. The samples were treated at an average absorbed dose of 4 kGy.
The quantity of the conjugated diens and triens formed during auto-oxidation, was determined by means of ultraviolet spectroscopy. The changes were traced on the 1st, 15th and 30th day from the beginning of the sample treatment, and the samples were stored under a temperature of 4 to 6oC.
The tendency established in the dynamics of the oxidation processes of the tested and control samples during that period showed a weak rise in the levels of the two para-meters (less expressed in the treated samples), which did not result in worse quality of the product and its organoleptic features.
Mathematical processing of the data shows that the dynamics of the oxidation processes is function of the time of storing, while gamma rays treatment has weak effect and can be neglected as a factor.
Keywords: lipids, oxidation, conjugated diens and triens, gamma rays treatment, salami.
ELECTROCHEMICAL PROTECTION OF INTERNAL SURFACES THROUGH ALUMINIUM ANODE DISSOLUTION
D. Ionova1, L. Fachikov2
1Technical University – Varna,
E-mail: ionova@mail.bg
2University of Chemical Technology and Metallurgy,
8 Kl. Ohridski, 1756 Sofia, Bulgaria
Received 09 March 2004
Accepted 31 May 2004
The electrochemical protection of internal surfaces of tanks, vessels and pipelines subjected to aggressive environment are discussed. Electrolytic installation with aluminium electrodes arranged as anode and cathode groups is developed for tank wall protection. The results indicate that if there is an electric circuit connecting the electrical supply, the electrodes and the tank walls playing a role of cathode the tank can be electrochemically protected. The laboratory results show that electrochemical dissolution of aluminium anode at 0.6 mg/l concentration of aluminium ions reduces corrosion rate of carbon steels in sea water.
Keywords: cathodic protection, sea water, heat exchanger.
USE OF COMPETITIVE ION EXCHANGE FOR INTERACTION OF BENTONITE WITH Cr (III) CHELATE
M. Atanassova, E. Kashchieva, I. Dukov
University of Chemical Technology and Metallurgy,
8 Kl. Ohridski, 1756 Sofia, Bulgaria
E-mail: dukov@uctm.edu
Received 20 April 2004
Accepted 20 May 2004
The intercalation of Cr(phen)3, (phen = phenanthroline) into the bentonite interlayers is studied. The samples have been characterized by IR, TEM and X-ray diffraction measurements. TG – DTA curves were recorded too. The presence of exchangeable cations in the interlayer space obtained by the treatment of the clay with 1M KCl, BaCl2 and FeCl3 solutions was discussed.
Keywords: intercalations, exchangeable cation, clay-chelate hybrid material.