"TITLE","AUTHORS","SUBJECT","SUBJECT_RELATED","DESCRIPTION","PUBLISHER","AVAILABILITY","RESEARCH_ORG","SPONSORING_ORG","PUBLICATION_COUNTRY","PUBLICATION_DATE","CONTRIBUTING_ORGS","LANGUAGE","RESOURCE_TYPE","TYPE_QUALIFIER","JOURNAL_ISSUE","JOURNAL_VOLUME","RELATION","COVERAGE","FORMAT","IDENTIFIER","REPORT_NUMBER","DOE_CONTRACT_NUMBER","OTHER_IDENTIFIER","DOI","RIGHTS","ENTRY_DATE","OSTI_IDENTIFIER","PURL_URL" "Coalescence of organic solutions in acid and metal extraction by tri-alkylamines; Demixtion des solutions organiques lors de l'extraction des acides et des metaux par les trialcoylamines","Blain, J [Commissariat a l'Energie Atomique, Fontenay-aux-Roses (France). Centre d'Etudes Nucleaires]","37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; AMINES; COALESCENCE; MICELLAR SYSTEMS; ORGANIC SOLVENTS; PARAMETRIC ANALYSIS; PHASE STUDIES; SALTS; SOLVENT EXTRACTION","","The formation of two layers with tri-alkylammonium salts solutions in low polarity diluents could be explained on the basis of settling of micelles. Light scattering and viscosity measurements reveal that micelles size increases rather sharply before coalescence. The existence of micelles in the solution has been confirmed by ultracentrifuge experiments. The behaviour of these solutions, in general, is similar to that of colloidal soap solutions. The various parameters which promote third phase formation are: anion size in the order of Cl{sup -} {approx} Br{sup -} < NO{sub 3} < ClO{sub 4}{sup -}; extraction of excess acid; metal cation size in the order of UO{sub 2}{sup ++} < Pu{sup 4+} {approx} Th{sup 4+}; decreasing in the length of the n-alkyl chain in the alkyl-ammonium salts; decreasing in diluent polarity. The above phenomenon could be explained on the basis of the affinity between alkylammonium salts and organic solvent. The composition of the three phases is independent of the initial amine concentration for a fixed acid and metal concentration. This has been verified experimentally and is in conformity with phase rule. (author) [French] La demixtion des solutions organiques de sels de trialcoyl-ammonium dans les solvants peu polaires est provoquee par la decantation des micelles presentes dans la solution. Nous avons montre par viscosimetrie et surtout par diffusion de la lumiere que les micelles grossissent de facon importante juste avant demixtion. Des experiences d'ultracentrifugation nous ont permis de confirmer la presence de micelles. Le comportement de ces solutions est analogue a celui des solutions colloidales de savons dans l'eau. Ainsi tous les parametres qui font decroitre la compatibilite du sel d'ammonium R{sub 3}NH+ oooX{sup -} avec le solvant organique favorisent l'agregation du sel et par consequent la demixtion, soient: l'extraction des anions de taille croissante Cl{sup -} {approx} Br{sup -} < NO{sub 3} < ClO{sub 4}{sup -}; l'extraction d'acide en exces; l'extraction des metaux dans l'ordre UO{sub 2}{sup ++} < Pu{sup 4+} {approx} Th{sup 4+}; la diminution de la longueur des chaines alcoyle de l'amine; les solvants organiques de polarite decroissante. Une etude thermodynamique nous a en outre permis de montrer que, pour un systeme d'extraction donne (amine, solvant; acide(metal)), il n'existe qu'une seule isotherme de dedoublement. (auteur)","","Available from INIS in electronic form","CEA Fontenay-aux-Roses, Dir. Centrale de la Securite, 92 (France); Faculte des Sciences de l'Universite de Paris, 75 (France)","","France","1970-07-01","","French","Thesis/Dissertation","","","","Other Information: TH: These ES sciences appliquees; 61 refs; PBD: 1970","","Medium: ED; Size: 60 pages","","CEA-R-3845","","TRN: FR04R3845007935","https://doi.org/","","2010-02-25","20552678","https://www.osti.gov/etdeweb/servlets/purl/20552678"