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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

S?ntese de tensoativos aminados e estudo das suas influ?ncias na molhabilidade de rochas carbon?ticas

Fernandes, J?ssica Emanuela de Ara?jo 25 April 2016 (has links)
Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2017-03-28T19:23:20Z No. of bitstreams: 1 JessicaEmanuelaDeAraujoFernandes_TESE.pdf: 2514876 bytes, checksum: 124c4f78a98f40c9e466558c72113259 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2017-03-29T00:13:38Z (GMT) No. of bitstreams: 1 JessicaEmanuelaDeAraujoFernandes_TESE.pdf: 2514876 bytes, checksum: 124c4f78a98f40c9e466558c72113259 (MD5) / Made available in DSpace on 2017-03-29T00:13:38Z (GMT). No. of bitstreams: 1 JessicaEmanuelaDeAraujoFernandes_TESE.pdf: 2514876 bytes, checksum: 124c4f78a98f40c9e466558c72113259 (MD5) Previous issue date: 2016-04-25 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (CAPES) / Neste trabalho foram sintetizados dois tensoativos cati?nicos cloreto de dodecilam?nio (DAC) e cloreto de N,N-dietildodecilam?nio (NNDAC) para investigar sua capacidade de alterar a molhabilidade de rochas carbon?ticas atrav?s do tratamento com sistemas micelares ou microemulsionados. A caracteriza??o destes compostos foi feita atrav?s de espectroscopia de infravermelho, ponto de fus?o e valores de concentra??o micelar cr?tica (c.m.c.). Os sistemas microemulsionados foram escolhidos de maneira a contemplar pontos ricos em mat?ria ativa, fase aquosa e fase oleosa e caracterizados por di?metro de got?cula, tens?o superficial, densidade e viscosidade. Os substratos calc?rio e carbonato de c?lcio utilizados foram caraterizados por espectroscopia de infravermelho por transformada de Fourier (FTIR), an?lise t?rmica (TG), difra??o de raios X (DRX) e fluoresc?ncia de raios X (FRX). Os sistemas microemulsionados preparados com DAC e caracterizados por micelas esf?ricas apresentaram menores di?metros de got?cula se comparados com os mesmos sistemas para o NNDAC, com valores entre 100 e 225 nm para o primeiro tensoativo e na faixa de 500 a 980 nm para o segundo tensoativo. O efeito salino proporcionou a redu??o das intera??es eletrost?ticas entre as cabe?as das mol?culas de tensoativo, ocasionando o empacotamento micelar com menor concentra??o e reduzindo os di?metros das part?culas. Os resultados de viscosidade e de tens?o superficial confirmaram os dados de tamanho de part?cula, j? que os sistemas com menores concentra??es de tensoativo apresentaram valores de viscosidade na faixa de 3 ? 4,5 cP, enquanto os sistemas com maiores concentra??es de mat?ria ativa, ou seja, que sugerem agregados estruturais maiores ? lamelas ? exibiram resultados entre 6,5 e 7,8 cP. A caracteriza??o dos substratos inorg?nicos mostrou a ocorr?ncia da fase calcita e a aus?ncia de subst?ncias ou contaminantes que comprometessem a rocha calc?ria utilizada. Os ensaios de molhabilidade mostraram que todos os tratamentos inverteram a molhabilidade da rocha carbon?tica de molh?vel ao ?leo para molh?vel ? ?gua, mas os menores valores de ?ngulo de contato foram obtidos ao trat?-la com os sistemas microemulsionados formados com o NNDAC em meio salino. Os sistemas microemulsionados caracterizados pela ocorr?ncia de lamelas foram os mais eficientes na diminui??o dos valores de ?ngulo de contato. J? os sistemas com micelas diretas promoveram menor modifica??o de molhabilidade. / In this work two cationic surfactants were synthesized, dodecylaminium chloride (DAC) and N, N-diethyldodecylaminium (NNDAC) to investigate their ability to change the of carbonate rock wettability with treatment with microemulsion systems. The surfactant characterization was carried out through infrared spectroscopy technique, melting point and critical micelle concentration values (c.m.c.). Microemulsions with high composition of active matter, aqueous and oily phase and phase were characterized by droplet diameter, surface tension, density and viscosity. The limestone and calcium carbonate used were characterised by Fourier Transform Infrared Spectroscopy, thermal analysis (TG), x-ray diffraction (XRD) and x-ray fluorescence (FRX). Microemulsion systems prepared with DAC and characterized as spherical micelles showed smaller droplet diameters compared with similar systems for the NNDAC, with values between 100 and 225 nm for the first surfactant and between 500 and 980 to the second. The salt effect caused the reduction of electrostatic interactions between the polar heads of surfactant molecules, causing the micelle packaging with lower concentration and reducing the diameters. Viscosity and surface tension results confirmed the particle size data. The systems with lower surfactant concentrations presented viscosity values in the range of 3-4.5 cP, while the systems with higher concentrations of active matter, i.e. that suggest larger structural aggregates - lamella - exhibited results between 6.5 and 7.8 cP. The characterization of inorganic substrates showed the occurrence of calcite phase and the absence of substances or contaminants that compromise the limestone used. The wettability tests showed that all treatments have reversed the carbonate rock wettability of oil wet to water wet, but the lower contact angle values were obtained through treatment with microemulsion systems formed with the NNDAC in saline media. Microemulsion systems characterized by the occurrence of lamella were the most effective to reduce the contact angle values while systems with direct micelle promoted smaller micelles wettability change.

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