Formulacija in karakterizacija naravnih polimernih nosilcev za vezavo pigmentov

doktorska disertacija

Tina Perko (Author), Mojca Škerget (Mentor), Željko Knez (Co-mentor)

Abstract

Prvi del doktorske disertacije je namenjen raziskavam faznih ravnotežij trigliceridov v sub- in superkritičnih fluidih. Podatki so ključni za nadalnje načrtovanje visokotlačnih separacijskih in formulacijskih procesov, saj so pripomogli k izboljšanju določenih industrijskih procesov v smeri okoljevarstva in kvalitete proizvodov. Za določitev topnosti glicerol tristearata-zgoščeni plini in glicerol trioleata-zgoščeni plini smo uporabili visokotlačno optično celico. Meritve smo izvedli pri različnih temperaturah (30, 50, 70 in 90 °C) in tlakih do 600 bar. Cilj našega eksperimentalnega dela je bilo pridobiti podatke o faznih ravnotežjih za glicerol tristearat in glicerol trioleat v sistemih superkritični CO2 in SF6, ki so ključnega pomena za optimizacijo visokotlačnih separacijskih in formulacijskih procesov. Podatkov o faznih ravnotežij glicerol tristearata-SF6 in glicerol trioleata-SF6 v literaturi ni. Pridobljeni podatki so novi in odpirajo nove perspektive za uporabo SF6 kot topila za različne nosilce. Za raziskave vpliva tlaka na temperaturo tališča in določitev talilne toplote v različnih plinih (dušik in CO2) smo uporabili visokotlačni DSC. Prav tako smo določiti topnosti in difuzijske koeficiente superkritičnega CO2 v različnih naravnih polimerih, ki se uporabljajo v prehrambeni industriji kot vezivo in sicer v različnih celulozah in škrobih. Topnost CO2 v polimeru je odvisna od temperature in tlaka, ter povzroča njegovo nabrekanje in s tem znižanje viskoznosti polimera. S povišanjem topnosti CO2 v polimeru se povečuje tudi masa polimera. Za določanje topnosti CO2 in difuzije smo uporabili magnetno suspenzijsko tehtnico. Meritve smo izvedli s pomočjo magnetne suspenzijske tehtnice pri različnih temperaturah (40, 60 in 80 °C) in tlakih do 300 bar. Določili smo visoke vrednosti topnosti in difuzijskih koeficientov ob izpostavitvi polimerov SC CO2. V nobenem primeru ni prišlo do raztapljanja polimera, ampak je polimer absorbiral CO2 in nabreknil. Iz dobljenih podatkov je razvidno, da topnost CO2 v polimerih z zviševanjem tlaka narašča in z zviševanjem temeperature pada. Zviševanje tlaka povzroča povečanje gostote plina in s tem večjo topnost, pri čemer se poveča volumen polimera. Z zviševanjem temperature pa se znižuje gostota plina. Difuzijski koeficienti CO2 so odvisni od koncentracije CO2 v polimeru. Na začetku se vrednosti difuzijskega koeficienta s povečanjem topnosti dvigajo, dokler CO2 ne zapolni vseh prostih praznin v polimeru, nato pa začnejo te vrednosti padati zaradi delovanja hidrostatičnega tlaka. Z določitvijo topnosti in difuzijskega koeficienta CO2 v polimerih pri določeni temperaturi in tlaku, smo pridobili več podatkov o faznem ravnotežju polimer-plin, ki so pomembni za razumevanje vpliva in optimiranje procesnih parametrov. V zadnjem delu doktorske disertacije smo vezali naravno rumeno barvilo kurkumin iz začimbe in 10 % tekočega ekstrakta na nosilce kot so trigliceridi, polietilen glikol, ciklodekstrin, celuloze in škrobi. Raziskovali smo različne kombinacije zmesi barvil in različnih nosilcev s superkritičnim CO2. Mikroniziranim praškastim produktom barvil kurkume smo izmerili povprečno velikost in povprečno porazdelitev velikosti nastalih delcev. Izvedli smo tudi superkritične in konvencionalne ekstrakcije kurkume (Curcuma longa L.). Naredili smo več različnih konvencionalnih ekstrakcij: ekstrakcija s hladnim topilom v bučki, Soxhlet ekstrakcija, ekstrakcija z ultrazvokom in ekstrakcija s konvencionalnim topilom pri povišanih tlakih. V dobljenih ekstraktih smo analizirali antioksidativno aktivnost s pomočjo pomočjo radikalske metode. Prav tako smo v ekstraktih določili antioksidacijske vrednosti s standardom Trolox. Preverili smo prisotnost kurkuminoidov v ekstraktih s tankoplastno kromatografijo in primerjali dobljene rezultate s HPLC analizo. V doktorski nalogi smo tudi preverili protimikrobno delovanje mikroniziranih vzorcev na različne bakterije in glive.

Keywords

trigliceridi;superkritični ogljikov dioksid;ravnotežne topnosti;naravni polimeri;superkritične ekstrakcije;kurkuminoidi;nanoenkapsulacija;sproščanje aktivne substance;ekonomska analiza;

Data

Language:	Slovenian
Year of publishing:	2014
Typology:	2.08 - Doctoral Dissertation
Organization:	UM FKKT - Faculty of Chemistry and Chemical Engineering
Publisher:	[T. Perko]
UDC:	543.635.32:54-139:547.979.4(043.3)
COBISS:	18195222
Views:	1994
Downloads:	224
Average score:	0 (0 votes)
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Other data

Secondary language:	English
Secondary title:	FORMULATION AND CHARACTERIZATION OF NATURAL POLYMERIC CARRIERS FOR PIGMENTS
Secondary abstract:	The first part of the dissertation is devoted to research of phase equilibria of triglycerides in sub and supercritical fluids. Data is key for further planning and formulation of high-pressure separation processes because they contributed to the improvement of certain industrial processes towards environmental protection and product quality. To determine the solubility of the glycerol tristearate-condensed gases and glycerol trioleate-condensed gases were used a high-pressure optical cell. The measurements were performed at different temperatures (30, 50, 70 and 90 ° C) and pressures up to 600 bar. The aim of our experimental work was to obtain information on the phase equilibria of glycerol and glycerol trioleate tristearate systems in supercritical CO2 and SF6, which are crucial for optimizing high-pressure separation and formulation processes. Data on the phase equilibria of glycerol tristearate-SF6 and SF6-glycerol trioleate in the literature is not. The data obtained are new and open up new prospects for the use of SF6 as a solvent for various media. For investigation of the influence of pressure to a temperature of the melting point and the determination of the melting heat of the various gas (nitrogen and CO2), we used high-pressure DSC. We have also determined the solubility and diffusion coefficient of the supercritical CO2 in a variety of natural polymers, which are used in the food industry as a binder, and in the various celluloses and starches. CO2 solubility in the polymer is dependent on temperature and pressure, as well as causing its swelling and thereby lowering the viscosity of the polymer. By increasing the solubility of CO2 in the polymer also increases the weight of the polymer. To determine the solubility of CO2 and diffusion, we used a magnetic suspension balance. The measurements were performed by means of magnetic suspension scales at different temperatures (40, 60, and 80 ° C) and pressures up to 300 bar. We determined high levels of solubility and diffusion coefficients of polymers when exposed to SC CO2. In any case, there was no dissolution of the polymer, but the polymer can absorb CO2 and swollen. From the obtained data it is clear that the solubility of CO2 in the polymers by increasing the pressure increases and decreases with increasing in temperature. Increasing pressure causes an increase in gas density and to improve the solubility, thereby increasing the volume of the polymer. By increasing the temperature is decreasing gas density. Diffusion coefficients of CO2 are dependent on the concentration of CO2 in the polymer. At the beginning, the value of the diffusion coefficient by increasing the solubility of the rise until the CO2 does not fill all free of voids in the polymer, and then apply these values to fall due to the action of hydrostatic pressure. By determining the solubility and diffusion coefficient of CO2 in polymers at a given temperature and pressure, we gain more information about the phase equilibrium polymer-gas, which are important for understanding and optimizing the process parameters. In the last part of the doctoral dissertation are bound natural yellow colorant curcumin from spices and 10% of the liquid extract on carriers such as triglycerides, polyethylene glycol, cyclodextrin, cellulose, and starches. We studied different combinations of colors and a mixture of various media with supercritical CO2. Micronized powder product dyes curcuma we measured the average size and the average size distribution of the resulting particles. We also supercritical and conventional extraction of turmeric (Curcuma longa L.). We have several different conventional extractions: extraction with cold solvent in a flask, Soxhlet extraction, ultrasonic extraction and extraction with conventional solvent at elevated pressures. The resulting extracts were analyzed antioxidant activity by means of using the free-radical methods. We are also in extracts determine the antioxidant value of the standard TROLOX.
Secondary keywords:	triglycerides;equilibrium solubility;natural polymers;diffusion coefficient;supercritical extraction;curcuminoids;nanoencapsulation;the release of active substances;the economic analysis;
URN:	URN:SI:UM:
Type (COBISS):	Dissertation
Thesis comment:	Univ. Maribor, Fak. za kemijo in kemijsko tehnologijo
Pages:	XXIII, 243 str.
ID:	8730872