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CONCLUSION The copolymers of PLGA-PEG-PLGA and ITA-PLGA-PEG-PLGA-ITA were synthesized and characterized by GPC and the test tube inverting method. The presence of the itaconic acid in the polymer chain caused the decrease in both CGC and CGT. The degradation of PLGA-PEG-PLGA was attended by the decreasing of molecular weight during ten days until the gel has dissolved. The number of the low molecular weight chains increased with time causing the increasing in polydispersity of the polymer. Acknowledgement I would like to thank Dr. Lucy Vojtová for the copolymers preparation and expert advice. This work was supported by the Ministry of Education of the Czech Republic under the research project MSM 0021630501. REFERENCES [1] A. Göpferich, Biomaterials 1996, 17, 103 – 114. [2] P. Giunchedi, B. Conti, S. Scalia, U. Conte: J. Contr. Rel. 1998, 56, 53 – 62. [3] S. Li,: Biomed. Mater. Res. 1999, 48, 342 – 353. [4] I. Grizzi, H. Garreau, S. Li, M. Vert: Biomaterials 1995, 16, 305 – 311. [5] B. Marcato, G. Paganetto, G. Ferrara, G. Cecchin: J. Chromatogr. B. 1996, 682, 147 – 156. [6] T. G. Park: J. Contr. Rel. 1994, 30, 161 – 173. [7] G. Schliecker, C. Schmidth, S. Fuchs, T. Kissel: Biomaterials 2003, 24, 3835 – 3844. [8] M. S. Shim, H. T. Lee, W. S. Shim, I. Park, H. Lee, T. Chang, S. W. Kim, D. S. Lee: J. Biom .Mat. Res. 2002, 61, 188 - 196 Sborník soutěže Studentské tvůrčí činnosti Student 2006 a doktorské soutěže O cenu děkana 2005 a 2006 Sekce DSP 2006, strana 222
STUDY OF THE COPPER(II) IONS NON–STATIONARY DIFFUSION IN HUMIC GEL Ing. Petr Sedláček, 1 st year of study Supervisor: doc. Ing. Martina Klučáková, PhD. Brno University of Technology, Faculty of Chemistry, Institute of Physical and Applied Chemistry, Purkyňova 118, 612 00 Brno, e–mail: sedlacek@fch.vutbr.cz INTRODUCTION Severe reduction of use of solid fossil fuels in the power–producing industry has markedly encouraged the investment to alternative applications of these materials. Humic acids (HA), which are one of their key components, are because of their rich natural sources, simple isolation methods and profitable chemical ad physical behavior predetermined for the wide– spread use in different industrial and agricultural branches. Although the intensive study of this material lasts for several decades the knowledge level (mainly concerning the structure of HA) is still quite low (it is often compared with the knowledge of proteins fifty years ago). Application of HA in a form of humic gel (see [1]) is quite new and unexplored field of their study. The gel form of HA is easy to prepare, suitable for the exploration of transport phenomena and mainly simulates the natural conditions; HA are usually found in the highly humid environment (water sediments, peat etc.) and thus in the swollen form. One of most famous and promising HA properties is the ability to bind metal ions. They can form stable complexes among others with heavy metals, which influences their toxicity in environment and this fact encourages potential applications of humic substances mainly in environmental industry, in the production of fertilizers and in pharmacy. Most important binding sites in HA molecule are carboxylic and phenolic groups and aromatic cycles. Besides the lower mobility of metal ions in humic gels comparing water solution, the diffusion in gels are influenced also by the retention or immobilization of the ions, both caused by chemical reaction between metals and HA. The result is that mathematical apparatus used in the description of diffusion phenomena is very complicated. Copper(II) ion is well–known for its high affinity to humic substances [2]. Besides this the HA–Cu(II) binding is among the highest strengths. Therefore and also because of easy quantification of copper content by means of spectroscopy, the copper(II) ions has been chosen as model metal ions for this work. The main aim of this research was the study of copper(II) ions diffusion from solutions with different Cu 2+ concentration into humic gel across the phase interface and the diffusion in the gel itself. Other experiment interested in the influence of other properties of the copper(II) source solution, namely the type of anion of copper salt, solution pH and ionic strength. EXPERIMENTAL PART HA were obtained from South-Moravia lignite by means of the alkaline extraction (see [2]). Humic gel was prepared by the technique optimized in [3]: HA were diluted in 0.5 M NaOH in the 8 g HA in 1 dm 3 Fig. 1 Humic gel sample NaOH ratio. This sodium humate solution was acidified by Sborník soutěže Studentské tvůrčí činnosti Student 2006 a doktorské soutěže O cenu děkana 2005 a 2006 Sekce DSP 2006, strana 223
Page 1 and 2: PRODUCTION OF SELECTED SECONDARY ME
Page 3 and 4: containing ampicillin, IPTG and x-g
Page 5 and 6: THE SIMPLE METHOD FOR THE RECOGNITI
Page 7 and 8: Figure 1 Negative-ion mode MALDI-TO
Page 9 and 10: Table 1 Evaluation of negative-ion
Page 11 and 12: Fig. 1: Scheme of the hydride gener
Page 13 and 14: [4] H. Matusiewicz, M. Kopras, J. A
Page 15 and 16: - are hypotriglyceridemic; - exhibi
Page 17 and 18: HYDROPHOBIZED SODIUM HYALURONATE IN
Page 19 and 20: spectrophotometer (AMINCO-Bowman, S
Page 21 and 22: Hyaluronate derivatives showed with
Page 23 and 24: copolymers were additionally functi
Page 25: Each micelle has a hydrophobic core
Page 29 and 30: CuSO4, Cu(ClO4)2 and Cu2P2O7 of the
Page 31 and 32: total flux [mol.m -2 ] 0.7 0.65 0.6
Page 33 and 34: number of free radicals is very low
Page 35 and 36: Differences can be caused by severa
Page 37 and 38: MEASUREMENT OF THERMOPHYSICAL PROPE
Page 39 and 40: The typical time responses of tempe
Page 41 and 42: Figure 4 illustrates the typical de
Page 43 and 44: sodium sulphate and filtered to a 5
Page 45 and 46: Compare all tested evening primrose
Page 47 and 48: IMPROVED FLUORIMETRIC DETERMINATION
Page 49 and 50: Al F i 80 70 60 50 40 30 20 10 0 0
Page 51 and 52: F i 60 50 40 30 20 10 Data UCL LCL
Page 53 and 54: PHYSICAL-CHEMICAL ASPECTS OF PAINT
Page 55 and 56: Finally, the solubility parameter o
Page 57 and 58: Study of the influence of different
Page 59 and 60: Fig.1: Chemical structures of pI ma
Page 61 and 62: Identification of pI markers - Firs

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