Influence of surfactant addition on the rheological properties of aqueous welan matrices
Autori: S. Manca, R. Lapasin, P. Partal, C. Gallegos Presentato al:Southern Europe Conference on Rheology Anno: 1999 Volume: 1 - Issue: Unico Casa Editrice: SIR-Cuen Napoli Lingua: English
Abstract
The role of surfactants is essential to provide long term stability to emulsions since they prevent droplet coalescence by adsorbing at the o/w interface and increasing the repulsive interactions among droplets. Another way of enhancing the stability of emulsions and other disperse systems is based on the addition of polymers as thickening agents. Their efficiency depends on polymer concentration in the aqueous phase as well as on the structural features of the aqueous polymer system. Indeed, the formation of a weak gel-like polymer network in the continuous phase leads to very high viscosities in the low stress range and impart additional elastic properties to the whole system so that emulsion creaming is strongly inhibited. Several aqueous polysaccharide systems exhibit weak-gel properties, even at low polymer concentration, in a sufficiently large temperature range and, hence, could be considered 'a priori' as valid candidates to display such a stabilizing role in emulsions. However, the creaming stability of emulsions containing polysaccharides can be sensitive not only to the biopolymer concentration but also to surfactant-biopolymer interactions, depending on the nature of surfactant.
Attenzione la lettura completa dell'Abstract e il download dei file è riservata esclusivamente ai Soci dell'Associazione Italiana di Reologia.
Se sei un Socio ti preghiamo di effettuare il login se non lo hai già fatto
Nel caso non fossi un Socio dell'Associazione Italiana di Reologia ti preghiamo di visitare la sezione "Iscriviti all'Associazione" per procedere alla registrazione
The XVIII edition of the SIR conference will be held in Villa Rosa, a recently renovated ancient Neapolitan villa in Capri Island (Naples, Italy), in September 12th-14th 2024. The event will be organised with the support of the Department of Chemical, Materials and Industrial Production Engineering of the University of Naples Federico II.
All those with an interest in rheology, in all its aspects, are invited to submit contributions.
Selected papers will be eligible for a special issue in Rheologica Acta.
L'Associazione Italiana di Reologia ha come scopo la promozione e lo sviluppo delle attività nel campo della reologia in relazione ai suoi aspetti teorici, sperimentali, didattici, applicativi e industriali.
L'organizzazione di incontri periodici e di un congresso Nazionale annuale permette lo sviluppo di contatti e incontri