Fatima Al-Ali

Publications (5)6.14 Total impact

• Source

  Available from: univ-toulouse.fr

  Article: Preparation and characterization of new hybrid organic/inorganic systems derived from calcium (alpha-aminoalkyl)-phosphonates and -phosphonocarboxylates.

  Fatima Al-Ali, Albert Lebugle, Isabelle Rico-Lattes, Guita Etemad-Moghadam
  [show abstract] [hide abstract]
  ABSTRACT: We have studied the phenomenon of calcium complexation by lab synthesized amphiphilic (alpha-aminoalkyl)-phosphonocarboxylic or -phosphonic acids. The electrical conductivity of aqueous solutions of sodium salts of all these acids was measured versus the volume of a calcium salt solution added. It appeared that calcium complexes are formed in a Ca/P atomic ratio close to 1. Calcium phosphonocarboxylates and calcium phosphonates were also precipitated by mixing aqueous solutions of disodium salts of phosphorus amphiphiles and calcium nitrate solutions. Before chemical analysis, these complexes were calcined to remove the organic part. In the mineralized products, calcium and phosphate were assayed: the Ca/P atomic ratio was equal to 1. X-ray diffraction and IR spectroscopy showed that they are made entirely of beta pyrophosphate (Ca2P2O7), a result in agreement with previous chemical analysis. The chemical formula of the starting calcium complexes could be written as CaL2H2O (L=ligand). The SEM micrographs of these complexes show plate-like structures. XRD patterns are characteristic of layered structures. These facts suggest that calcium complexes are composed of alternating bimolecular layers of calcium alkylphosphonocarboxylates or calcium alkylphosphonates, the chains being tilted and partially interdigitated.
  Journal of Colloid and Interface Science 10/2005; 289(2):504-11. · 3.07 Impact Factor
• Article: Langmuir films of (alpha-amino) phosphorus amphiphiles on various ion-containing subphases.

  Fatima Al-Ali, Christophe Déjugnat, Guita Etemad-Moghadam, Isabelle Rico-Lattes
  [show abstract] [hide abstract]
  ABSTRACT: Monolayers of amphiphilic (alpha-amino)phosphonocarboxylic and (alpha-amino)phosphonic acids have been formed by adsorption at the air/water interface. The influence of both the ionic strength and the pH of the subphase on the stability and compactness of the monolayers have been studied. The stability and the compactness of the Langmuir films are enhanced by introduction of metallic ions such as Ca(2+) or Mg(2+) in the subphases. These effects are more pronounced with Ca(2+). These metal ions can form dimeric complexes with the phosphorus moieties of the surfactant polar heads and therefore bring the amphiphiles closer. For the less hydrophobic derivative, complexation with Ca(2+) or Mg(2+) is required to ensure the formation of a stable monomolecular film. For both phosphonocarboxylic and phosphonic compounds, models have been proposed to represent the complexation phenomenon at the air/water interface.
  Journal of Colloid and Interface Science 06/2004; 273(2):512-6. · 3.07 Impact Factor
• Article: New Catanionic Amphiphiles Derived from the Associative Systems (α-Hydroxyalkyl)-phosphinic or (α-Hydroxyalkyl)-phosphonic Acid/Cetyltrimethylammonium Hydroxide. Preparation, Characterization, and Self-Organization Properties

  Fatima Al-Ali, Alice Brun, Fernanda Rodrigues, Guita Etemad-Moghadam, Isabelle Rico-Lattes
  [show abstract] [hide abstract]
  ABSTRACT: New phosphorous catanionic amphiphiles were easily prepared by an acid−base reaction between (α-hydroxyalkyl)-phosphinic or -phosphonic acid and cethyltrimethylammonium hydroxide. In this way, we obtained, in nearly quantitative yields, bicatenary phosphinates and bicatenary and tricatenary phosphonates. The aggregation properties of these new catanionic amphiphiles were investigated at low concentrations in water (ranging from 1 to 5 mM), focusing in particular on spontaneous formation of different aggregate morphologies (vesicles, ribbons, tubules). Light and electron microscopy was used to identify the aggregate morphology of the catanionic amphiphiles. Moreover, these catanionic amphiphiles were able to organize into ordered lyotropic mesophases in concentrated water solutions, visualized by optical polarizing microscopy. Finally, the phosphorous catanionic amphiphiles, without rigid cores, were unexpectedly found to show thermotropic liquid-crystalline behavior. The various thermotropic mesophases were characterized by the formation of optical textures. Rigidification by ionic interactions could promote the formation of these thermotropic mesophases.
  07/2003;
• Article: Self-Organization Properties of New (α-Aminoalkyl)phosphonic- and (α-Aminoalkyl)phosphonocarboxylic Acid Amphiphiles in Water and at the Air/Water Interface

  Christophe Déjugnat, Fatima Al Ali, Karine Vercruysse-Moreira, Guita Etemad-Moghadam, Isabelle Rico-Lattes
  [show abstract] [hide abstract]
  ABSTRACT: We have studied the surfactant properties of a series of single- and double-chain (α-aminoalkyl)phosphonocarboxylic- and (α-aminoalkyl)-phosphonic acid amphiphiles, prepared in nearly quantitative yields by one-pot selective hydrolysis of the mixture obtained by reacting P−H bond tetraoxyspirophosphorane and long-chain aldimines. Disodium salts of monocatenary derivatives are soluble in water and the cmc's were determined by tensiometry, showing surfactant properties for all compounds. Thermodynamic calculations confirmed the tensiometry results, in the sense that phosphonocarboxylates present much more electrostatic destabilizing repulsions favoring micellization less than phosphonates. The disodium salts of these phosphonic acids were able to organize into ordered lyotropic mesophases in concentrated water solutions, visualized by optical polarizing microscopy. The nature of the observed mesophases seems to be strongly dependent on the polar head structure. All compounds were studied using the Langmuir technique. The more hydrophobic derivatives formed stable monolayers versus time at the air/water interface. The areas occupied per molecule depend on the polar head structure and the number of alkyl chains. The conformations at the air/water interface were estimated by a molecular modeling study.
  11/2002;
• Article: Preparation and characterization of new hybrid organic/inorganic systems derived from calcium (aminoalkyl)-phosphonates and -phosphonocarboxylates

  Fatima Al-Ali, Albert Lebugle, Isabelle Rico-Lattes, Guita Etemad-Moghadam
  [show abstract] [hide abstract]
  ABSTRACT: We have studied the phenomenon of calcium complexation by lab synthesized amphiphilic (α-aminoalkyl)-phosphonocarboxylic or -phosphonic acids. The electrical conductivity of aqueous solutions of sodium salts of all these acids was measured versus the volume of a calcium salt solution added. It appeared that calcium complexes are formed in a Ca/P atomic ratio close to 1. Calcium phosphonocarboxylates and calcium phosphonates were also precipitated by mixing aqueous solutions of disodium salts of phosphorus amphiphiles and calcium nitrate solutions. Before chemical analysis, these complexes were calcined to remove the organic part. In the mineralized products, calcium and phosphate were assayed: the Ca/P atomic ratio was equal to 1. X-ray diffraction and IR spectroscopy showed that they are made entirely of β pyrophosphate (Ca2P2O7), a result in agreement with previous chemical analysis. The chemical formula of the starting calcium complexes could be written as CaL·2H2O (L= ligand). The SEM micrographs of these complexes show plate-like structures. XRD patterns are characteristic of layered structures. These facts suggest that calcium complexes are composed of alternating bimolecular layers of calcium alkylphosphonocarboxylates or calcium alkylphosphonates, the chains being tilted and partially interdigitated.