Chemistry Journal of Moldova

Physical chemistry and chemical physics

APPLICATION OF TAGUCHI OPTIMIZATION METHOD IN THE PREPARATION OF ACTIVATED CARBON BY MICROWAVE TREATMENT

Author(s):

Oleg Petuhov


Field: Physical chemistry and chemical physics
Type: Research paper
Issue: 2015 Volume 10, no.1
Pages: 95-103
Keywords: activated carbon, walnut shells, microwave radiation, experimental design, analysis of variance.
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Abstract (PDF)

DOI:
dx.doi.org/10.19261/cjm.2015.10(1).14

Graphical Abstract: 
This paper reports on the preparation of activated carbon from walnut shell. Orthogonal array experimental design method was used to optimize the preparation of activated carbon with phosphoric acid by using microwave treatment. The optimization parameters were: microwave power, activation time, phosphoric acid concentration and particle sizes of nut shells. Thermal analysis of the intact and impregnated with phosphoric acid walnut shells was used for the simulation of activation process. Activated carbon with the optimal parameters was obtained, being characterized by gas adsorption method and scanning electron microscopy.

 

Downloads: 52

TOWARDS SCREENING THE ENHANCE OF LUMINESCENCE PROPERTIES OF MODIFIED TANNINS IN ALKALINE SOLUTION BY A FENTON-LIKE REACTION

Author(s):

Alexandru Gonta


Field: Physical chemistry and chemical physics
Type: Research paper
Issue: 2015 Volume 10, no.1
Pages: 104-112
Keywords: oxidation, tannins, free radical, chemiluminescence.
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Abstract (PDF)

DOI:
dx.doi.org/10.19261/cjm.2015.10(1).15

Graphical Abstract:
 After modification of enotannins, flavonols monomer units could be obtained with polyfunctional properties. Moreover, polyphenols are known to generate H2O2 and other ROS under alkaline conditions. ROS generation and catalytic influence of ferrous ions enhance the chemiluminescence light. Therefore in this work, Tox/Tris-Edta/Fe2+ ions have been used for screening luminescent properties of oxidized tannins.


Downloads: 60

POLYMER NANOCOMPOSITE BASED ON STYRENE WITH BUTYL METHACRYLATE AND INORGANIC SEMICONDUCTOR CdS

Author(s):

Mihail Iovu, Marius Enachescu, Ion Culeac, Victor Verlan, Stefan Robu, Dionezie Bojin, Iurie Nistor, Ion Cojocaru


Field: Physical chemistry and chemical physics
Type: Research paper
Issue: 2014 Volume 9, no.2
Pages: 74-79
Keywords: nanocomposite, polymer matrix, photoluminescence, exciton
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Abstract (PDF)

DOI:
dx.doi.org/10.19261/cjm.2014.09(2).11

Graphical Abstract:
 We present experimental results on copolymer-based nanocomposite made of styrene with butyl methacrylate (1:1) and inorganic semiconductor CdS. Thin film composite samples have been characterized by UV-Vis absorption and photoluminescent spectroscopy, as well as by transmission electron microscopy.

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ELECTRONIC CONTROL OF MOLECULAR CONFIGURATION INSTABILITY VIA VIBRONIC COUPLING. PSEUDO JAHN-TELLER STABILIZATION OF VERTICALLY EXCITED STATES OF F2CO, N2H2 AND H2C2O MOLECULES

Author(s):

Natalia Gorinchoy


Field: Physical chemistry and chemical physics
Type: Research paper
Issue: 2014 Volume 9, no.2
Pages: 80-89
Keywords: Pseudo Jahn-Teller effect, stereochemistry, excited states, carbonyl fluoride, diazene, ketene
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Abstract (PDF)

DOI:
dx.doi.org/10.19261/cjm.2014.09(2).12

Graphical Abstract:
 The pseudo Jahn-Teller effect is employed to explane the origin of structural distortions of carbonyl fluoride, diazene and ketene molecules in the lowest singlet and triplet excited states. It was shown that in all the cases the distortions of the molecules in the excited states are due to the vibronic mixing of considered states with the appropriate by symmetry higher-lying excited states.



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IODIDE IONS SORPTION ON POLYMER AV-17(Cl) AND SORBENT AV-17(Bi)

Author(s):

Vasile Gutsanu


Field: Physical chemistry and chemical physics
Type: Research paper
Issue: 2014 Volume 9, no.2
Pages: 90-98
Keywords: strongly basic anion exchanger, iodide ions, sorption, Bi(III) compounds
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Abstract (PDF)

DOI:
dx.doi.org/10.19261/cjm.2014.09(2).13

Graphical Abstract:
 The iodide ions sorption from solutions of KI and KI in excess of KCl has been investigated. The strongly basic anion exchangers AV-17 in Cl- form and Varion AD in NO3- form were used as sorbents. Also AV-17 polymer modified with Bi(III)-containing compounds were used. The sorption was performed in static and dynamic conditions. Isotherms are approximated with BET sorption model. The sorption value of iodide ions in the KI solutions with KCl in excess is quite high. It was established that sorption of iodide ions in the form of polyiodide occurs both as a result of anion exchange and as a result of chemisorption.


Downloads: 29

LACTOFERRIN: ANALYSIS OF THE STRUCTURE PROFILE

Author(s):

Lilia Anghel


Field: Physical chemistry and chemical physics
Type: Research paper
Issue: 2014 Volume 9, no.2
Pages: 99-106
Keywords: iron, protein, lactoferrin, transferrin, multiple sequence alignment
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Abstract (PDF)

DOI:
dx.doi.org/10.19261/cjm.2014.09(2).14

Graphical Abstract:
 The multitude of physiological processes in which the binding of iron ions takes part makes its mechanism worth investigating. The multiple sequence alignment method was applied to investigate the structure similarities of five lactoferrin X-ray crystallographic structures and outline the differences and similarities between lactoferrin and serum transferrin. The results of this study provide useful insights into the mechanism of iron-binding of lactoferrin molecule.



Downloads: 69

MALDI-TOF INVESTIGATION OF LYSOZYME-ALBUMIN INTERACTION

Author(s):

Marharyta Vasylieva, Taras Gromovoy


Field: Physical chemistry and chemical physics
Type: Short communication
Issue: 2014 Volume 9, no.2
Pages: 107-110
Keywords: MALDI-TOF, albumin, lysozyme, protein-protein interaction
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Abstract (PDF)

DOI:
dx.doi.org/10.19261/cjm.2014.09(2).15

Graphical Abstract: 
Proteins are the main components of living systems therefore they are a subject of study from different points of view. Under certain conditions, proteins are capable of self-organization forming oligomeric structures of various composition and new properties. The investigations of these transformations were carried out on two well known proteins: albumin and lyzozyme. It is shown that associates of albumin and lysozyme are formining in the stoichiometric ratios of 1:1, 1:2, 1:3, 1:4. A similar pattern is observed in the case of albumin dimer.



Downloads: 58

HOLOGRAPHIC INFORMATION MEDIA BASED ON AZO-POLYMERS WITH DIFFERENT STRUCTURES

Author(s):

Irina Davidenko


Field: Physical chemistry and chemical physics
Type: Research paper
Issue: 2014 Volume 9, no.1
Pages: 112-116
Keywords: azobenzene, metallic polycomplexes, polymer composition, electrooptical effect, polarization holohraphy
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Abstract (PDF)

DOI:
dx.doi.org/10.19261/cjm.2014.09(1).14

Graphical Abstract:
 Polarization sensitive holographic recording was accomplished in new synthesized azobenzene polymer composites with Co metallic polycomplexes of different structure.



Downloads: 25

HOLOGRAPHIC RECORDING MEDIA BASED ON ELECTRONS DONOR OLIGOMERS

Author(s):

Nicolay Davidenko, Irina Davidenko, Nicolay Chuprina, Yuriy Getmanchuk., Leonid Kostenko, Elena Mokrinskaya, Valeriy Pavlov, Sergey Studzinsky, Larisa Tonkopieva


Field: Physical chemistry and chemical physics
Type: Research paper
Issue: 2014 Volume 9, no.1
Pages: 117-122
Keywords: carbazole, oligomer, photothermoplastic, holographic recording
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Abstract (PDF)

DOI:
dx.doi.org/10.19261/cjm.2014.09(1).15

Graphical Abstract: 
Information properties of recording media based on electrons donor oligomer of different structure for thermoplastic technique are investigated.




Downloads: 17

AMINOSILICA NANO- AND SUBMICROSPHERES: ANALYSIS OF FACTORS INFLUENCING MORPHOLOGY, STRUCTURE AND PROPERTIES

Author(s):

Inna Melnyk


Field: Physical chemistry and chemical physics
Type: Research paper
Issue: 2014 Volume 9, no.1
Pages: 123-127
Keywords: silica nanoparticles and submicrospheres, aminopropyl groups, Stöber method
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Abstract (PDF)

DOI:
dx.doi.org/10.19261/cjm.2014.09(1).16

Graphical Abstract:
 Current paper focuses on the analysis of influence of main factors (stages of the synthesis, the ratio of the reacting components, the order of their introduction, the concentration of water and ammonia, the synthesis temperature) on the morphology, size and content of functional groups of aminosilicanano- and submicrospheres. The recommendations for the synthesis of particles with predetermined properties were done. It is shown, that the ratio of the reacting components mainly affects the content of 3-aminopropyl functional groups and the temperature of the hydrolytic polycondensation reaction - the size of the particles.



Downloads: 41