Structural and multi-scale rheophysical investigation of diphasic magneto-sensitive materials based on biopolymers.
We present a structural and a multi-scale rheophysical investigation of magneto-sensitive materials based on biopolymers, namely aqueous solutions of sodium alginate incorporating magnetic maghemite nanoparticles, functionalized with adsorbed negative citrate ions. The large alginate ionic strength impacts the structure and the rheology of these nanocomposites in zero magnetic field. In given physico-chemical conditions, the system is fluid and homogeneous on macroscopic scales while it is diphasic on microscopic ones, containing micro-droplets coming from the demixion of the system. These micro-droplets are liquid and deformable under magnetic field. Their under-field elongation and their zero-field relaxation are directly observed by optical microscopy to determine their interfacial tension, their magnetic susceptibility and their internal viscosity. A structural analysis of the solutions of alginate chains and of the phase-separated mixtures of alginate and nanoparticles by Small Angle Scattering completes the local description of the system.
UPMC Univ Paris 06, CNRS, Lab. PHENIX, Case 51, Sorbonne Universités, 4 place Jussieu, F-75005, Paris, France.
Stéphane
S
Roger
Yan Yip Cheung
YY
Sang
Agnès
A
Bee
Régine
R
Perzynski
Jean Marc
JM
Di Meglio
Alain
A
Ponton
D000464:Alginates / Q000737:chemistry*; D001704:Biopolymers / Q000737:chemistry*; D020723:Glucuronic Acid / Q000737:chemistry; D006603:Hexuronic Acids / Q000737:chemistry; D060526:Magnetic Fields; D058185:Magnetite Nanoparticles / Q000737:chemistry*; D053761:Nanocomposites / Q000737:chemistry; D009994:Osmolar Concentration; D012212:Rheology; D014783:Viscosity
D000464:Alginates; D001704:Biopolymers; D006603:Hexuronic Acids; D058185:Magnetite Nanoparticles; D020723:Glucuronic Acid