02045nas a2200265   4500008004100000022001400041245006600055210006600121260005700187300001200244490000700256520123100263653002601494653002001520653000901540653001201549653001401561653001301575653001301588100002201601700001901623700002001642700002101662856009601683       2013                        eng d  a0035-451100aAscertaining universal features of yielding of soft materials0 aAscertaining universal features of yielding of soft materials  a233 SPRING ST, NEW YORK, NY 10013 USAbSPRINGERcNOV  a859-8650 v523 a<p>Many metastable complex fluids, when subjected to oscillatory shear flow of increasing strain amplitude at constant frequency, are known to show a characteristic nonlinear rheological response which consists of a monotonic decrease in the elastic modulus and a nonmonotonic change in the loss modulus. In particular, the loss modulus increases from its low strain value, crosses the elastic modulus, and then decreases with further increase in the strain amplitude. Miyazaki et al. (Europhys Lett 75:915-921, 2006) proposed a qualitative argument to explain the origin of the nonmonotonic nature of the loss modulus and suggested that in fact this response could be universal to all complex fluids if they are probed in a certain frequency window in which the fluid is dominantly elastic in the small strain limit. In this letter, we confirm their hypothesis by showing that a wide variety of complex fluids, irrespective of their thermodynamic state under quiescent conditions, indeed show the aforementioned characteristic nonlinear response. We also show that the maximum relative dissipation during yielding occurs when the imposed frequency resonates with the characteristic beta relaxation frequency of the fluid.</p>10aColloidal suspensions10aEntangled melts10aGels10aGlasses10aMicrogels10aRheology10aYielding1 aKamble, Samruddhi1 aPandey, Anurag1 aRastogi, Sanjay1 aLele, Ashish, K.  uhttp://library.ncl.res.in/content/ascertaining-universal-features-yielding-soft-materials-002057nas a2200217   4500008004100000022001400041245010900055210006900164260000800233300001000241490000800251520131600259653001301575653002501588653001401613653001801627100002201645700002101667700002301688856012801711       2019                        eng d  a0021-979700aAlternating electric-field-induced assembly of binary mixtures of soft repulsive ionic microgel colloids0 aAlternating electricfieldinduced assembly of binary mixtures of   cMAY  a88-950 v5443 a<p>An external alternating electric field is used to study the assembly of a binary mixture of Poly(N-isopro pylacrylamide-co-acrylic acid) microgels in their swollen form at hydrodynamic size ratio 2:1 under deprotonated state. The AC field experiments were carried out at a fixed frequency of 100 kHz in the fluid regime for three number density ratios 1:3, 1:1 and 3:1 of big-to-small microgels using a confocal microscope. Strings with different types of co-assembly structures such as buckled, ring, flame and sandwich have been observed at low and intermediate field strengths at ratio 1:3, 1:1. In buckled and ring type, one or two small particles sit at the contact of two big particles and in the flame type, small particles arrange like a cone at end of the string. In the sandwich structure, several double small particle layers lie in between big particles. At high field strength, aggregation of strings and a phase separation into individual aggregates of strings from both big and small microgels have been observed. At higher ratio 3:1, the string formation is mostly dominated by big particles. Our experimental results are discussed with the recent simulation and experimental works on AC field induced structures in binary hard sphere mixtures. (C) 2019 Elsevier Inc. All rights reserved.</p>10aassembly10adipolar interactions10aMicrogels10aSoft colloids1 aJathavedan, Kiran1 aBhat, Suresh, K.1 aMohanty, Priti, S.  uhttp://library.ncl.res.in/content/alternating-electric-field-induced-assembly-binary-mixtures-soft-repulsive-ionic-microgel