[en] In this doctoral thesis, an experimental study on the transport properties on liquid mixtures has been conducted. The molecular di usion coe cient, thermodi usion coe cient and Soret coe cient of several mixtures have been analyzed. The molecular di usion coe cient has been measured by the sliding symmetric tubes technique, while the thermodi usion coe cient has been determined using the thermogravitational technique. The Soret coe cient, on the other hand, has been calculated using the data obtained with these two experimental techniques. Di erent types of mixtures have been analyzed using these techniques. On the one hand, several binary mixtures, specifically mixtures of hydrocarbons, aqueous mixtures and polymer mixtures, have been studied. In the group of hydrocarbon mixtures, the thermodi usion, molecular di usion and Soret coefficients at 25 °C of three equimolar and equimass normal alkane series have been determined (49 binary mixtures). The analysis of the obtained data has been used to develop three correlations for the prediction of the transport properties of the binary mixtures composed by these components. The first of these expressions, is a quantitative correlation which is used for the determination of the thermodi usion coe cient in normal alkane binary mixtures at any concentration. The second quantitative correlation developed, does the same thing but with the molecular di usion coe cient, using the data of the molecular mass di erence of the components and the dynamic viscosity of the mixture. The experimental data obtained for the Soret coefficient has been used to develop another quantitative correlation for the determination of this coefficient. In the case of aqueous mixtures, measurements of the transport properties in water-isopropanol mixture in the whole range of concentration at 25 °C have been carried out. The experimental analysis of this mixture has also been done by other laboratories (Service de Chimie physique E.P. and Microgravity Resesarch Center, both from university of Brussels, and Department of Physics from university of Bayreuth), both in ground and microgravity conditions. The results obtained in this international collaboration work, can be considered as a consistent reference data for the mixtures which present a sign change in the Soret coe cient over their concentration range. For polymer mixtures, a combination of the sliding symmetric tubes and the gravimetric techniques has been used to study the water-polyacrylamide binary system in collaboration with FAST laboratory of Pierre et Marie Curie university. The analysis carried out using these two techniques has allowed the determination of the molecular di usion coe cient of the mixture throughout the concentration range of the three regimes that can be found in this mixture: concentrated, diluted and semi-diluted. Additionally, measurements of the thermodi usion coe cient in ternary hydrocarbon mixtures have been done. Two of these mixtures tetrahydronaphthalene-isobutylbenzene-ndodecane and toluene-nhexane-ndodecane) at several concentrations and 25 °C have been analyzed. The data measured has been used to analyze and check the reliability degree of a correlation developed in a previous work. This correlation is able to predict the thermodiffusion coe cient in ternary mixtures using the data of their corresponding binary mixtures.

[eu] Doktoretza-tesi honetan nahasketa likidoen garraio-ezaugarri buruzko azterketa esperimentala egin da. Sistema ezberdinetako difusio-molekular, termodifusio eta Soret koefizienteak aztertu dira. Difusio-molekular koefizientea, hodi simetriko irristakor teknikarekin neurtu da. Termodifusio koefizientea, beste aldean, teknika termograbitazioarekin neurtu da, Soret koefizientea, beste bi teknikekin lortutako datuekin kalkulatuz. Nahasketa desberdinak ikertu izan dira teknika hauek erabiliz. Alde batean likido-nahaste bitarrak aztertu dira. Hauen artean hidrokarburoen nahasketak, ur-nahasketak eta polimeroen nahasketak aurkitzen dira. Hidrokarburoen nahasketen kasuan, hiru alkano serie ekimolar eta hiru alkano serie ekimasikoen termodifusio, difusio-molekular eta Soret koefizienteak 25 gradutara zehaztu dira (49 nahaste bitarrak). Lortutako datuak aztertuz, konposatu hauen garraio-ezaugarriak iragartzeko hiru korrelazio garatu dira. Lehenengo korrelazio kuantitatiboa, hidrokarburoen nahasketa bitarretan edozein kontzentrazioetan termodifusio koefizientea zehazteko aukera ematen du. Garatutako bigarren korrelazio kuantitatiboa gauza berdina egiten du baina difusiomolekular koefizientearekin, nahasketaren biskositate eta bere konposatuen masa molekularren diferentzien datuak erabiliz. Soret koefizientean lortutako emaitz esperimentalak, bestalde, koefiziente hau zehazteko beste korrelazio kuantitatibo bat garatzeko erabili dira. Ur-nahasketen kasuan, ura eta isopropanolen arteko nahasketako garraio-propietateak kontzentrazio tarte osoan ikertu dira. Nahasketa hau beste laborategi batzuetan ere esperimentalki ikertu da (Service de Chimie physique E.P. eta Microgravity Resesarch Center, biak Brusela-ko unibertsitatekoak eta Department of Physics Bayreuth-eko unibertsitatekoa), lur eta mikrograbitate kondizioetan. Nazioarteko mailan egindako ikerketa honetan lortutako emaitzak erreferentzia bezala hartu ahal dira, Soret koefizientean zeinu aldaketa daukaten nahasketetan. Polimero nahasketetan, ura-poliakrilamida sisteman, hodi simetriko irristakor eta grabimetriko tekniken konbinazioa erabiliz, difusio-molekular koefizientea neurtu da. Analisi hau Pierre et Marie Curie unibertsiteko FAST taldearekin egindako elkar lana izan da. Bi teknika hauen konbinazioa erabiliz, nahasketa honen difusio-molekular koefizienteak kontzentrazio tarte guztietan, nahasketa honek daukadan hiru erregimenetan (kontzentratua, diluitua eta semi-diluitua) neurtu dira.