BEGIN:VCALENDAR VERSION:2.0 PRODID:-//CERN//INDICO//EN BEGIN:VEVENT SUMMARY:Keynote 2 - Scattering and microscopy probes in colloidal systems under shear: Linking structure and dynamics with mechanical response DTSTART;VALUE=DATE-TIME:20181210T135000Z DTEND;VALUE=DATE-TIME:20181210T143000Z DTSTAMP;VALUE=DATE-TIME:20260522T224733Z UID:indico-contribution-67-499@lindico453.srv.lu.se DESCRIPTION:Speakers: George Petekidis (Materials science & Technology\, U niversity of Crete\, Greece)\nThe microscopic structure and dynamics in co lloidal systems at different length-scales\, from single to multiple parti cle level\, are probed under shear by a variety of scattering and direct i maging techniques. We present different studies of hard and soft particle glasses and attractive gels of spherical and rod-like colloids\, where we link the mechanical response with the underlying particle dynamics and str ucture.\nYielding of colloidal glasses under large amplitude oscillatory s hear was probed by simultaneous rheometry and light scattering with the LS -echo technique. We studied a range of colloidal systems with varying inte rparticle interactions from hard and soft sphere glasses to attractive gla sses and gels. LS-echo probes reversible and irreversible rearrangements t hat are linked with rheological yielding of the system.\nSecondly we discu ss the mechanisms responsible for a variety of shear induced structures in attractive colloidal gels and their relation to linear and nonlinear rheo logy. We use a combination of rheological experiments and rheo-confocal me asurements with computer simulations. In such thixotropic systems steady a nd oscillatory shear can be used as an external field to tune the structur e and mechanical properties of colloidal gels and drive them in metastable states\, not easily accessible at quiescent conditions.\nFinally\, we pre sent shear induced structural formations gels of attractive rod-like collo ids. More specifically we discuss the rheological response and flow induce d clustering of silica rods in a density matching solvent\, where electros tatic repulsions are screened via the addition of CsCl. A variety of simul taneous imaging techniques and rheometry reveals structural changes at dif ferent length-scales. Shear induced log-rolling clusters in the vorticity direction are formed driven by an interplay of hydrodynamic interactions\, confinement and a balance of shear and attractive forces. Structural form ation is discussed as a function of volume fraction\, shear rate\, gap siz e\, tool geometry as well as shear history.\n\nhttps://lindico453.srv.lu.s e/event/67/contributions/499/ LOCATION:Elite Hotel Ideon Tera URL:https://lindico453.srv.lu.se/event/67/contributions/499/ END:VEVENT BEGIN:VEVENT SUMMARY:Keynote 5 - Combining in-situ\, time-resolved SANS\, SAXS/WAXS and SALS\, to study molecular and crystal alignment in bottlebrushes polymers during uniaxial deformation DTSTART;VALUE=DATE-TIME:20181211T080000Z DTEND;VALUE=DATE-TIME:20181211T084000Z DTSTAMP;VALUE=DATE-TIME:20260522T224733Z UID:indico-contribution-67-484@lindico453.srv.lu.se DESCRIPTION:Speakers: Carlos Lopez-Barron (ExxonMobile Chemical Company\, USA)\nMolecular bottlebrushes are branched polymers with very high graft d ensity which results in very rigid backbones. This conformation provides u nique rheological properties compared to linear polymer melts. For instanc e\, their very large entanglement molecular weight (Me) results in very lo w elastic modulus\, which could be used to produce super-soft elastomers [ Pakula et al.\, Polymer 47\, 7198 (2006)]. Despite the growing interest in bottlebrush polymers\, very few studies have been devoted to their linear viscoelastic response\, whereas\, to our knowledge\, no study has been re ported on their extensional rheology or their response to cold-drawing. We synthesized a series of ultra-high molecular weight (UHMW) a-olefin molec ular bottlebrushes by organometallic coordinative insertion polymerization of 1-alkenes with lengths ranging from 8 to 18 carbons. The molecular wei ght of these polymers are in the order of a few million g/mol\, which allo ws accurate measurement of their rubbery plateau modulus (GN0) and their M e values. The latter is an increasing function of the side chain length (N sc) and takes values ranging from 25 kg/mol (for poly(1-octene)) to 115 kg /mol (for poly(1-octadecene)). Therefore\, our bottlebrush polymers are hi ghly-entangled and have sufficient melt strength to perform extensional rh eology measurements using a commercial Sentmant extensional rheometer (SER ). Bottlebrush chain alignment was measured using a novel method that comb ines the use of a SER with time-resolved small-angle neutron scattering (S ANS) measurements [López-Barrón et al.\, J Rheol. 61\, 697 (2017)]. The latter uses state of the art methods of neutron time stamping in the SANS detector and deconvolution protocols that yields scattering data with time resolutions of the order of seconds [López-Barrón et al.\, Phys. Rev. L ett. 108\, 258301\; Calabrese et al.\, Soft Matter 12\, 2301 (2016)]. Thos e measurements were used to confirm the direct correlation between extensi onal stress and bottlebrush chain alignment. Complementary\, in situ wide- and small-angle X-ray scattering measurements reveal that chain alignment is concomitant of self-assembly of the bottlebrush molecules into hexagon al packed cylinder (HEX) phases induced by uniaxial extension. This work r eports the first direct evidence of strain-induced alignment and packing o f molecular bottlebrushes and their relation with the macroscopic rheologi cal and mechanical responses.\n\nhttps://lindico453.srv.lu.se/event/67/con tributions/484/ LOCATION:Elite Hotel Ideon Tera URL:https://lindico453.srv.lu.se/event/67/contributions/484/ END:VEVENT BEGIN:VEVENT SUMMARY:Keynote 3 - Vorticity banding in shear-thickening suspensions DTSTART;VALUE=DATE-TIME:20181210T150000Z DTEND;VALUE=DATE-TIME:20181210T154000Z DTSTAMP;VALUE=DATE-TIME:20260522T224733Z UID:indico-contribution-67-500@lindico453.srv.lu.se DESCRIPTION:Speakers: Romain Mari (CNRS\, University Grenoble-Alpes\, Fran ce)\nDiscontinuous shear thickening of dense suspensions is a phenomenon i n which\, at a specific shear rate\, the viscosity increases discontinuous ly often by orders of magnitude. Recent modeling of the phenomenon suggest s that the viscosity jump in rate-controlled rheometry corresponds to an u nderlying S-shaped flow curve in stress-controlled conditions. This nonmon otonic rheology was observed in simulations with modest particle numbers\, showing a range of shear stresses for which the shear rate is a decreasin g function of the shear stress. In general\, however\, one expects that fo r large enough systems a decreasing flow curve leads to a mechanical linea r instability of the uniform flow and the appearance of banding or rheo-ch aos in the nonlinear regime. The exact mode of instability is nonetheless quite difficult to predict in absence of a proper tensorial constitutive m odel. In this talk I will show particle-based numerical simulations of thi ckening suspensions exhibiting an instability along the vorticity directio n and subsequent "traveling" vorticity bands. Interestingly\, because the mechanical description of the vorticity direction can be decoupled from th e flow and gradient directions\, a one-dimensional (scalar) constitutive m odel is enough to capture most of the features observed in the simulations . This model also gives hints as to the origin of the unsteady rheological response observed in experiments performed in similar conditions.\n\nhttp s://lindico453.srv.lu.se/event/67/contributions/500/ LOCATION:Elite Hotel Ideon Tera URL:https://lindico453.srv.lu.se/event/67/contributions/500/ END:VEVENT BEGIN:VEVENT SUMMARY:Keynote 4 - Quantitative Light Microscopy of Dense Suspensions: Co lloid Science at the Next Decimal Place DTSTART;VALUE=DATE-TIME:20181210T162000Z DTEND;VALUE=DATE-TIME:20181210T170000Z DTSTAMP;VALUE=DATE-TIME:20260522T224733Z UID:indico-contribution-67-503@lindico453.srv.lu.se DESCRIPTION:Speakers: Itai Cohen (Physics\, Cornell University\, USA)\n“ Why should one wish to make measurements with ever increasing precision? B ecause the whole history of physics proves that a new discovery is likely to be found lurking in the next decimal place.” (Floyd K. Richtmyer\, 19 31)\n\nSince the days of Perrin\, microscopy methods have played an import ant role in the study of colloidal suspensions. Along with the continued d evelopment of new imaging techniques\, colloid scientists have also implem ented a sophisticated range of computational analyses. These analysis tech niques are often the unsung heroes that hold the promise of unlocking scie ntific mysteries at the next decimal place of colloid science. They now en able precision measurements of particle location and size with nm precisio n as well as measurements of local stresses and forces. Here\, I spotlight exciting recent advances we have made focusing on the analysis of simple confocal microscope images of dense colloidal suspensions. I will then des cribe our plans for using these tools to unravel scientific mysteries rang ing from yielding in glasses\, training of colloidal gels\, and the stress networks governing shear thickening flows.\n\nhttps://lindico453.srv.lu.s e/event/67/contributions/503/ LOCATION:Elite Hotel Ideon Tera URL:https://lindico453.srv.lu.se/event/67/contributions/503/ END:VEVENT BEGIN:VEVENT SUMMARY:Contr. Talk 13 - Studying slow dynamics with X-ray photon correlat ion spectroscopy DTSTART;VALUE=DATE-TIME:20181212T103000Z DTEND;VALUE=DATE-TIME:20181212T105000Z DTSTAMP;VALUE=DATE-TIME:20260522T224733Z UID:indico-contribution-67-483@lindico453.srv.lu.se DESCRIPTION:Speakers: Oier Bikondoa (ESRF-The European Synchrotron\, Greno ble\, France)\nScattering experiments based on coherent X-ray beams have o pened new possibilities for the investigation of soft and hard condensed m atter. X-ray photon correlation spectroscopy (XPCS) allows to access a wid e variety of dynamic phenomena at the nanoscale by studying the temporal c orrelations among photons that are scattered by a material when it is illu minated using a coherent X-ray beam. \nWe present two examples of XPCS stu dies on systems with slow dynamics that illustrate the capabilities of the technique in SAXS and GISAXS geometries: (a) Dynamics of ion beam eroded surfaces\, which represent a paradigmatic case of sustained non-equilibriu m dynamics governed by the complex interplay between the mechanisms that t end to roughen and smoothen the surface [1]\; (b) An ongoing study on the initial steps of self-assembly mechanism and gelation of a pH-sensitive lo w molecular weight hydrogelator\, controlling both assembly rate and morp hology of the self-assembled structures.\nWe shall also discuss on the ben efits and possibilities that the new diffraction limited storage rings bri ng about for XPCS studies.\n\nhttps://lindico453.srv.lu.se/event/67/contri butions/483/ LOCATION:Elite Hotel Ideon Tera URL:https://lindico453.srv.lu.se/event/67/contributions/483/ END:VEVENT BEGIN:VEVENT SUMMARY:Keynote 10 - Phase Mapping with Microfluidic-SANS and Predictive D esign of Polymeric Microcapsules DTSTART;VALUE=DATE-TIME:20181212T080000Z DTEND;VALUE=DATE-TIME:20181212T084000Z DTSTAMP;VALUE=DATE-TIME:20260522T224733Z UID:indico-contribution-67-480@lindico453.srv.lu.se DESCRIPTION:Speakers: Joao Cabral (Dept. of Chemical Engineering\, Imperia l College London\, UK)\nMicrofluidics provides an exceptional platform for the generation of polymer solution droplets and their subsequent manipula tion. We describe the formation of polymeric particles and capsules induce d by solvent extraction\, with broad applications in the pharmaceutical an d consumer good industries. A microflow approach to perform small angle ne utron scattering (SANS) and phase mapping of multicomponent liquid mixture s is first described\, and the development of reconfigurable microfluidic- SANS. By contrast with conventional techniques\, our approach continually varies solution composition during SANS acquisition\, enabling global fits of large\, constrained datasets\, leading to unprecedented robustness and precision. After establishing the phase diagram of model polymer and coll oidal solutions\, we obtain a capsule morphology diagram\, attaining inter nal morphologies encompassing nucleated and bicontinuous microstructures\, as well as isotropic and non-isotropic external shapes. Equipped with thi s knowledge\, we design and fabricate composite capsules and particles wit h prescribed structure and pulsed release profile\, with time scales tunab le from seconds to hours.\n\nhttps://lindico453.srv.lu.se/event/67/contrib utions/480/ LOCATION:Elite Hotel Ideon Tera URL:https://lindico453.srv.lu.se/event/67/contributions/480/ END:VEVENT BEGIN:VEVENT SUMMARY:Contr. Talk 12 - Effect of confinement on lyotropic lamellae dynam ics under shear flow DTSTART;VALUE=DATE-TIME:20181212T101000Z DTEND;VALUE=DATE-TIME:20181212T103000Z DTSTAMP;VALUE=DATE-TIME:20260522T224733Z UID:indico-contribution-67-482@lindico453.srv.lu.se DESCRIPTION:Speakers: Luigi Gentile (Department of Biology\, Microbial Eco logy Group\, Lund University)\nLyotropic lamellar phases under shear flow show surprising changes in the microscopic structures and physical propert ies. Lamellae-to-multi-lamellar-vesicle (MLV) transition has been widely i nvestigated\, whereas lamellae tilting and vesicles inclination have not b een highlighted during this kind of transition. Flow instabilities and the ir correlation with structures and properties in a confined gap is also ma tter of investigation. Here time-resolved flow-small angle neutron scatter ing (SANS) experiments have been carried out using a 1-2 shear cell to det ect inclination and deformation of the MLVs and to correlate spatially dis tributed structures in the Couette gap with progressive evolution of the l ocal viscosity towards two significantly different values\, leading to sta ble and periodic viscosity oscillations. The inclination angle of the MLVs has been addressed in terms of capillary number and its spatial behavior along the Couette gap in terms of gap confinement.\n\nhttps://lindico453.s rv.lu.se/event/67/contributions/482/ LOCATION:Elite Hotel Ideon Tera URL:https://lindico453.srv.lu.se/event/67/contributions/482/ END:VEVENT BEGIN:VEVENT SUMMARY:Keynote 11 - Development of µRheoSANS and Investigating the Struc ture and Rheology of Complex Fluids at High Shear Rate DTSTART;VALUE=DATE-TIME:20181212T093000Z DTEND;VALUE=DATE-TIME:20181212T101000Z DTSTAMP;VALUE=DATE-TIME:20260522T224733Z UID:indico-contribution-67-481@lindico453.srv.lu.se DESCRIPTION:Speakers: Katie Weigandt (National Inst. of Science and Techno logy Center for Neutron Research\, USA)\nWe are developing slit rheometer s compatible with simultaneous small angle neutron scattering (SANS) measu rements to directly correlate structure and rheology over a broad range of conditions. Eventually we hope to probe sample structure in Poiseuille fl ow at high shear rates\, under high pressure head\, and relatively high te mperatures. This builds upon an existing suite of Couette rheoSANS and flo wSANS devices at the NIST Center for Neutron Research that are accessible to the scientific community through a peer reviewed proposal system. Indus trial applications\, such as lubrication\, mixing\, spraying and injection \, involve the flow of complex fluids at high deformation rates. Clogging\ , fluid degradation\, and other processing challenges can arise in these e xtreme contexts and are often driven by structural changes in the fluid. T o date\, we have developed a prototype slit rheometer capable of simultane ously measuring structure and rheology of relatively low viscosity or shea r thinning fluids (η∞ < 5 mPa∙s) at shear rates up to 100\,000 s-1 an d a capillary rheoSANS instrument capable of simultaneously measuring stru cture and rheology at rates up to 106 s-1. Our initial investigations have focused on measuring wormlike micelle solutions at low to moderate shear rates and comparing the results with Couette rheoSANS measurements. In thi s talk we will discuss the ongoing development of µRheoSANS measurements including our existing low-pressure apparatus\, the capillary device and o ur newly built high pressure µRheoSANS device\, designed to withstand pre ssure drops or pressure heads up to 350 bar. This device will enable us to measure SANS at shear rates up to 106 in samples with η∞ ~ 100 mPa∙s . Furthermore\, we will discuss the results of a series of experiments aim ed at understanding the rheological response of wormlike micelle solutions at relatively high shear rates.\n\nhttps://lindico453.srv.lu.se/event/67/ contributions/481/ LOCATION:Elite Hotel Ideon Tera URL:https://lindico453.srv.lu.se/event/67/contributions/481/ END:VEVENT BEGIN:VEVENT SUMMARY:Contr. Talk 11 - SAXS on a chip: from alignment phenomena at inter faces to dynamics of phase transitions studied with microfluidic devices DTSTART;VALUE=DATE-TIME:20181211T145000Z DTEND;VALUE=DATE-TIME:20181211T151000Z DTSTAMP;VALUE=DATE-TIME:20260522T224733Z UID:indico-contribution-67-495@lindico453.srv.lu.se DESCRIPTION:Speakers: Bruno Silva (INL - International Iberian Nanotechnol ogy Laboratory)\nThe field of microfluidics offers attractive possibilitie s to perform novel experiments that are difficult to execute using convent ional methods [1]. First\, the flow of liquids under submillimeter confine ment leads to predictable and controllable flow profiles\, along with well -defined chemical gradients and stress fields that can be used for control led mixing and actuation on the micro and nanoscale. Secondly\, intricate microfluidic device designs can be fabricated to perform complex tasks. Th irdly\, microfluidic devices are usually compatible with in situ or integr ated characterization methods that allow constant real-time monitoring of the processes occurring inside the microchannels. \nIn this work we will f ocus on the use and prospects of combining microfluidic devices with in si tu small-angle X-ray scattering (SAXS) for soft matter research. In a firs t example\, we use this manipulation ability to create well-defined flowin g interfaces to study the interplay between shear-flow forces and the stru cture of nematic liquid crystals and surfactant monolayers [2]. In a secon d example\, we study the structural evolution of a lamellar phase undergoi ng a transition to a microemulsion in the SDS-pentanol-water ternary syste m by mixing with water or pentanol in a crossed microchannel configuration [3]. By manipulating the individual flow-rates\, one can carefully tune t he final composition following the concentration jump\, and furthermore\, probe different time-scales of the transition with SAXS. The main findings show that the lamellar to o/w microemulsion transition (by mixing with wa ter) occurs through a gradual stripping down of bilayers from the lamellar phase\, whereas the lamellar to w/o reverse microemulsion transition (thr ough mixing with pentanol) involves the formation of an intermediate lamel lar phase.\n\nhttps://lindico453.srv.lu.se/event/67/contributions/495/ LOCATION:Elite Hotel Ideon Tera URL:https://lindico453.srv.lu.se/event/67/contributions/495/ END:VEVENT BEGIN:VEVENT SUMMARY:Contr. Talk 10 - Orientation distribution of cellulose nanofibrils and nanocrystals in channel flow DTSTART;VALUE=DATE-TIME:20181211T143000Z DTEND;VALUE=DATE-TIME:20181211T145000Z DTSTAMP;VALUE=DATE-TIME:20260522T224733Z UID:indico-contribution-67-494@lindico453.srv.lu.se DESCRIPTION:Speakers: Tomas Rosen (Stony Brook University)\nNature has a r emarkable way of creating complex hierarchical nanostructures of cellulose nanofibrils (CNF) into various forms of trees and plants. Depending on lo cal environment\, evolution has tailored these structures over millions of years to enhance the particular species’ chances of survival. Learning from nature\, we explore the possibility to tailor the properties of cellu lose materials materials to suit our needs by hydrodynamically aligning th e CNF and assembling them through controlled gelation and subsequent dryin g. The orientation distribution of CNF will depend on various parameters i ncluding flow properties such as deformation state (e.g. shear and extensi on) and flow rates as well as CNF properties such as fibril length distrib ution and concentration. In this work\, we study the orientation of CNF an d cellulose nanocrystals (CNC) in the shear layers of a channel flow using small angle X-ray scattering. The results are compared with simulations o f dilute anisotropic Brownian particles. Furthermore\, we demonstrate how polarized microscopy can be used to estimate the orientation distribution of these birefringent dispersions in the channel as well as determine thei r rotary diffusion rates. The results greatly enhance our understanding of CNF dynamics in flows\, which in turn can lead to new strategies in contr olling the structure of nanofibrous materials.\n\nhttps://lindico453.srv.l u.se/event/67/contributions/494/ LOCATION:Elite Hotel Ideon Tera URL:https://lindico453.srv.lu.se/event/67/contributions/494/ END:VEVENT BEGIN:VEVENT SUMMARY:Keynote 8 - Studying the influence of molecular conformation on ex tensional rheology by combining filament stretching rheometry with ex-situ SANS DTSTART;VALUE=DATE-TIME:20181211T130000Z DTEND;VALUE=DATE-TIME:20181211T134000Z DTSTAMP;VALUE=DATE-TIME:20260522T224733Z UID:indico-contribution-67-492@lindico453.srv.lu.se DESCRIPTION:Speakers: Qian Huang (Chemical Engineering\, Technical Univers ity of Denmark)\nExtensional flow is a major type of deformation in many p olymer processing operations such as blow molding and fiber spinning. Exte nsional rheology of polymer melts is highly sensitive to molecular archite cture and conformation. In the past four decades\, people have made a grea t effort to study the dynamics of polymer chains in extensional flow in or der to predict the rheological behaviour by using constitutive equations b ased on molecular theories (e.g. the tube model). However\, while producin g pure extensional flow in a highly controlled manner (e.g. constant strai n rate) is already a challenge\, rheology measurements give indirect infor mation of molecular conformation in terms of stress-strain responses only. Thus combining state-of-the-art extensional rheometry with scattering tec hniques provides a powerful tool to understand polymer dynamics.\n\nIn thi s work\, we measure the extensional rheology of polystyrene (PS) melts usi ng a filament stretching rheometer which is able to produce a well-defined extensional flow. We show that the rheological behaviour of PS melts with different molecular architectures (linear and star shaped) is identical i n fast extensional flow\, indicating the same molecular conformation. The hypothesis of the same molecular conformation is confirmed in small angle neutron scattering (SANS). We also measure a bi-disperse PS blend containi ng linear chains of two molecular weights\, and a monodisperse PS melt con taining the short linear chains only\, in stress relaxation following a fa st extensional flow. By combing rheological measurements with SANS measure ments\, we show that there are nematic effects and strain coupling between the short and long chains in the blend. Furthermore\, we show that the ch ain stretch idea in the tube model can be critically tested through analys ing the SANS data at different time in stress relaxation process.\n\nhttps ://lindico453.srv.lu.se/event/67/contributions/492/ LOCATION:Elite Hotel Ideon Tera URL:https://lindico453.srv.lu.se/event/67/contributions/492/ END:VEVENT BEGIN:VEVENT SUMMARY:Keynote 7 - Molecular Rheology of Entangled Polymeric Fluids: New Discoveries and Remaining Challenges DTSTART;VALUE=DATE-TIME:20181211T105000Z DTEND;VALUE=DATE-TIME:20181211T113000Z DTSTAMP;VALUE=DATE-TIME:20260522T224733Z UID:indico-contribution-67-489@lindico453.srv.lu.se DESCRIPTION:Speakers: Bamin Khomami (Chemical & Biomolecular Engineering\, The University of Tennessee\, USA)\nQuantitative understanding of the inf luence of environmental variables on the dynamic evolution of microstructu re in polymeric fluids plays a central role in soft matter physics as well as the processing of a wide variety of soft materials. Atomistic simulati on via non-equilibrium molecular dynamics (NEMD) offer a viable alternativ e to experiment wherein the dynamics of individual macromolecules can be t racked independently\, thus allowing for relevant calculations of their si ngle-chain configurational properties as well as the individual chain cont ributions to bulk-average properties. Specifically\, large scale NEMD simu lation results of entangled polymeric fluids allow examination of the fund amental tenants of reputation/ tube based theories including calculation o f essential variables such as the tube orientation tensor\, tube stretch\, and disengagement and Rouse times.\nIn this presentation\, I will briefly review the progress made in fundamental understanding of non-equilibrium dynamics of polymeric melts as well as the remaining challenges in develop ment of a unified approach for quantitative prediction of dynamics of this class of fluids in processing flows commonly used to produce structural a nd functional soft materials. Specifically\, I will discuss\, Non-Equilibr ium Molecular Dynamics Simulations (NEMD) results of linear monodisperse e ntangled macromolecular melts in shear and extensional flows that depict e xistence of new phenomena that challenges the fundamental tenants of reput ation/tube based theories and models used to describe fast flow of entangl ed polymeric fluids. In turn\, the intricate connection between single cha in dynamics and the macroscopic response of this class of fluids including the intriguing phenomena of shear banding and configurational microphase separation in planar extensional flows will be discussed.\nAcknowledgments : Financial support was provided by the National Science Foundation under Grant No. CBET-1602890.Computational resources for this project were provi ded by allocation of advanced computational resources by the National Inst itute for Computational Sciences (NICS) and the Oak Ridge National Laborat ory Joint Institute for Computational Sciences. This work also used the Ex treme Science and Engineering Discovery Environment (XSEDE)\, which is sup ported by National Science Foundation grant number ACI-1548562/TG-CTS15005 4.\n\nhttps://lindico453.srv.lu.se/event/67/contributions/489/ LOCATION:Elite Hotel Ideon Tera URL:https://lindico453.srv.lu.se/event/67/contributions/489/ END:VEVENT BEGIN:VEVENT SUMMARY:Contr. Talk 7 - Spherical Harmonics Expansion show Chain Retractio n DTSTART;VALUE=DATE-TIME:20181211T090000Z DTEND;VALUE=DATE-TIME:20181211T092000Z DTSTAMP;VALUE=DATE-TIME:20260522T224733Z UID:indico-contribution-67-486@lindico453.srv.lu.se DESCRIPTION:Speakers: Anine Borger (Niels Bohr Institute\, University of C openhagen)\nThe mechanical properties of polymer melts under deformation a re well described by the tube model developed in the 1970s by de Gennes an d Doi and Edwards. In the model\, the restricted motion of a chain due to its neighbors is modeled as if the chain ia confined to a tube. However\, the validity of the tube model for rapid deformations compared to the mole cular relaxation was recently questioned [1]. They proposed a new analysis method for anisotropic 2D small angle (neutron) scattering\, SANS\, data for uniaxially extended polymer melts expanding the data in spherical harm onics to ease the separation of the isotropic and anisotropic contribution s. Using this method\, they looked for the signature of chain retraction\, see below\, during relaxation after deformation which is a cornerstone of the tube model. The signature was absent in their data which lead them to conclude that chain retraction either does not occur or that it is shield ed by some other non-linear effect not yet included in the model. However\ , we employ the same analysis also on SANS data for a polystyrene melt of about a factor of five lower molar mass stretched more than a factor of te n more\, and we do see the proposed signature in the harmonics: The minimu m in the expansion coefficient of the leading anisotropic contribution to the scattering pattern shifts towards larger q as the relaxation times app roaches the Rouse time\, τR. We therefore conclude that the relaxation of the molecular stretching and orientation are decoupled\, or in other word s that the chain retracts\, which supports the tube model.\nChain retracti on arises during relaxation if the deformation is fast enough to not only orient the chains but also stretch them. The hypothesis of the tube model is that the relaxation of the stretching of the molecule happens on a fast time scale\, τR\, through a Rouse-like process whereas the relaxation of the orientation happens on a much slower timescale through repetition. Th at these timescales are well separated causes the molecule to shrink in al l dimensions for t∼τR does it relax back to its equilibrium shape.\n\nh ttps://lindico453.srv.lu.se/event/67/contributions/486/ LOCATION:Elite Hotel Ideon Tera URL:https://lindico453.srv.lu.se/event/67/contributions/486/ END:VEVENT BEGIN:VEVENT SUMMARY:Contr. Talk 5 - The effects of high-power ultrasound on colloidal gels DTSTART;VALUE=DATE-TIME:20181210T170000Z DTEND;VALUE=DATE-TIME:20181210T172000Z DTSTAMP;VALUE=DATE-TIME:20260522T224733Z UID:indico-contribution-67-505@lindico453.srv.lu.se DESCRIPTION:Speakers: Noémie Dagès ()\nLow-intensity ultrasound is widel y used to probe and image biological tissues.Yet\, yltrasound can also be used at high power to destroy nodules or burn tumors. We try to transpose and understand the latter effects in soft matter. We first show that high- power ultrasound softens colloidal gels. Upon applying ultrasound at 45kHz for a few tens of seconds on various gels in a rheometer\, we find that t he elastic modulus of the gel is weakened and that its fluidization is fas tened. As ultrasound is turned off\, the gel recovers its elasticity. To i nvestigate this process at the micron scale\, we then probe the gel under ultrasound with small-angle X-ray scattering (ESRF\, ID02). These experime nts show a strong effect of the ultrasound excitation on the SAXS spectra both on a colloidal gel at rest and under flow.\n\nhttps://lindico453.srv. lu.se/event/67/contributions/505/ LOCATION:Elite Hotel Ideon Tera URL:https://lindico453.srv.lu.se/event/67/contributions/505/ END:VEVENT BEGIN:VEVENT SUMMARY:Contr. Talk 2 - Orientation distributions of plate-like colloidal particles in complex flows – a synchrotron X-ray diffraction study DTSTART;VALUE=DATE-TIME:20181210T133000Z DTEND;VALUE=DATE-TIME:20181210T135000Z DTSTAMP;VALUE=DATE-TIME:20260522T224733Z UID:indico-contribution-67-498@lindico453.srv.lu.se DESCRIPTION:Speakers: Adrian Rennie ()\nSpatially resolved\, X-ray diffrac tion with synchrotron radiation permits detailed maps of the alignment of crystalline colloidal particles to be deduced and compared with fluid mech anics calculations of the flow. The angular distribution of diffracted int ensity from a given position in the pipe provides information about the or ientation distribution of the particles. Orientational alignment in a disp ersion of kaolinite particles has been investigated in several geometries. These include a uniform pipe\, at bends as well as a flow pattern that co mbines both shear and elongational stress\, namely flow at a jet created b y a 2 mm diameter nozzle inserted in a 6 mm diameter pipe [1\,2]. The alig nment is quantified and presented in terms of order parameters. The orient ation at different positions in a cylindrical pipe can be correlated with the Peclet number at different locations. The cone-shaped nozzle provides a jet of liquid giving a high degree of alignment of the particles that is uniform along lines across the conical section and constant in the small straight-sided region at the exit of the nozzle. The vortex motion that ar ises from the flow with a modest Reynolds number could be determined as we ll as the tendency for some particles to align with their large faces perp endicular to the overall flow direction at the flat surface of the nozzle outlet. Older studies will related to new challenges related to 3D-printin g polymer composites.\n\nhttps://lindico453.srv.lu.se/event/67/contributio ns/498/ LOCATION:Elite Hotel Ideon Tera URL:https://lindico453.srv.lu.se/event/67/contributions/498/ END:VEVENT BEGIN:VEVENT SUMMARY:Contr. Talk 1 - Sedimentation Induced Flow and Anomalous Dynamics in Field Driven Self-assembly of Magnetic Colloids Studied by XPCS DTSTART;VALUE=DATE-TIME:20181210T131000Z DTEND;VALUE=DATE-TIME:20181210T133000Z DTSTAMP;VALUE=DATE-TIME:20260522T224733Z UID:indico-contribution-67-497@lindico453.srv.lu.se DESCRIPTION:Speakers: Antara Pal (Division of Physical Chemistry\, Lund Un iversity)\nWe have studied the non-equilibrium dynamics of self-assembled magnetic peanut-shaped colloids in the presence of a magnetic field. The m icrometre‐sized particles align in a direction perpendicular to the appl ied external magnetic field\, and assemble into chains along the field dir ection. The anisotropic dynamics of these particles is investigated using multispeckle ultrasmall‐angle X‐ray photon correlation spectroscopy (U SA‐XPCS). Perpendicular to the applied field\, which is also the directi on of gravity\, a sedimentation induced flow develops. XPCS allows us to i nvestigate the resulting anisotropic dynamics\, and in particular to decou ple contributions from the sedimentation induced flow\, thermal diffusion of the assembled chains and individual particles\, and the internal collec tive dynamics of the assembled mesoscopic structures over a large range of length scales. Our experiments demonstrate the power of XPCS to investiga te complex dynamic processes that arise due to a combination of diffusive and flow-induced processes. Given the very small scattering volume probed in an XPCS experiments\, this opens up interesting possibilities for inves tigation spatially heterogeneous dynamics in highly turbid media that cann ot be probed with optical techniques.\n\nhttps://lindico453.srv.lu.se/even t/67/contributions/497/ LOCATION:Elite Hotel Ideon Tera URL:https://lindico453.srv.lu.se/event/67/contributions/497/ END:VEVENT BEGIN:VEVENT SUMMARY:Keynote 1 - X-ray imaging of flowing concentrated suspensions DTSTART;VALUE=DATE-TIME:20181210T123000Z DTEND;VALUE=DATE-TIME:20181210T131000Z DTSTAMP;VALUE=DATE-TIME:20260522T224733Z UID:indico-contribution-67-496@lindico453.srv.lu.se DESCRIPTION:Speakers: Guillaume Overlez (CNRS\, University of Bordeaux\, F rance)\nA key element to understand the rheological behavior of suspension s is their microstructure: the spatial distribution of particles depends o n flow history\, which has an impact on the suspension macroscopic propert ies. This appeals for the development of experimental tools allowing for t he 3D imaging of particles in viscosimetric flows. \nAt a macroscopic scal e\, concentrated suspensions often display concentration inhomogeneities\, due to shear-induced migration. These inhomogeneities can lead to the for mation of jammed regions\, which have a strong impact on the measured beha vior. It is crucial to describe this phenomenon near the jamming transitio n and in shear-thickening fluids. It is thus necessary to develop new tool s to get time- and spatially-resolved concentration fields in flowing susp ensions.\nIn this talk\, we present recent developments to tackle these is sues with the help of X-ray Imaging.\nWe first present a technique to imag e the microstructure of suspensions of non-Brownian particles in 3D\, usin g X-ray computed tomography and sub-voxel identification of particle cente rs. We illustrate its interest on a few examples. We show that one can get an isotropic microstructure after mixing. Under shear\, the microstructur e becomes anisotropic in the shear plane\, whereas it is isotropic in the 2 other planes. While for Newtonian suspensions the anisotropy is independ ent on the shear rate\, we show that for a yield-stress suspension it depe nds on it\; this implies a shear-dependent behavior of the suspension. Fin ally\, we evidence particle alignment along both solid surfaces and free i nterfaces.\nWe then present a technique to get time-resolved 2D concentrat ion fields in a rheometric flow\, thanks to 2D X-ray radiography. We illus trate its interest for shear-thickening fluids. We show that most suspensi ons display strong concentration inhomogeneities at the onset of Discontin uous Shear thickening (DST)\, which poses the question of the intrinsic (l ocal) behavior of DST suspensions and might lead to revisit the interpreta tion of this behavior.\n\nhttps://lindico453.srv.lu.se/event/67/contributi ons/496/ LOCATION:Elite Hotel Ideon Tera URL:https://lindico453.srv.lu.se/event/67/contributions/496/ END:VEVENT BEGIN:VEVENT SUMMARY:Contr. Talk 4 - Linking transient shear profiles to the microscopi c structure and dynamics in concentrated colloidal suspensions DTSTART;VALUE=DATE-TIME:20181210T160000Z DTEND;VALUE=DATE-TIME:20181210T162000Z DTSTAMP;VALUE=DATE-TIME:20260522T224733Z UID:indico-contribution-67-502@lindico453.srv.lu.se DESCRIPTION:Speakers: Andreas Pamvouxoglou (Heinrich Heine University Duss eldorf)\nWe performed start-up experiments with concentrated hard-sphere s uspensions around the glass transition. Rheo-confocal experiments were car ried out to link the macroscopic rheological response to the single-partic le structure and dynamics. During the start-up of shear\, suspensions of l arge particles (diameter ≈1.6μm) showed a transient non-linear velocity \, resembling shear bands without a clear boundary. We performed a quantit ative analysis to elucidate the correlation between the shear profile and microscopic properties\, such as the local velocity\, shear rate and volum e fraction. They show a strong dependence on the position in the gap and h ence indicate a significant heterogeneity. Based on the microscopic proper ties we propose a mechanism that leads to the transient non-linear shear p rofiles.\n\nhttps://lindico453.srv.lu.se/event/67/contributions/502/ LOCATION:Elite Hotel Ideon Tera URL:https://lindico453.srv.lu.se/event/67/contributions/502/ END:VEVENT BEGIN:VEVENT SUMMARY:Contr. Talk 3 - Flow-assisted droplet assembly in a 3D microfluidi c channel DTSTART;VALUE=DATE-TIME:20181210T154000Z DTEND;VALUE=DATE-TIME:20181210T160000Z DTSTAMP;VALUE=DATE-TIME:20260522T224733Z UID:indico-contribution-67-501@lindico453.srv.lu.se DESCRIPTION:Speakers: Zhouyang Ge ()\nSelf-assembly of soft matter\, such as droplets or colloids\, has become a promising scheme to engineer novel materials\, model living matter\, and explore non-equilibrium statistical mechanics. In this talk\, we present detailed numerical simulations of few non-Brownian droplets in various flow conditions\, specifically\, focusin g on their self-assembly within a short distance in a three-dimensional (3 D) microfluidic channel\, cf. [Shen et al.\, Adv. Sci.\, 2016\, 3(6):16000 12]. Contrary to quasi two-dimensional (q2D) systems\, where dipolar inter action is the key mechanism for droplet rearrangement\, droplets in 3D con finement produce much less disturbance to the underlying flow\, thus exper iencing weaker dipolar interactions. Using confined simple shear and Poise uille flows as reference flows\, we show that the droplet dynamics is most ly affected by the shear-induced cross-stream migration\, which favors cha in structures if the droplets are under an attractive depletion force. For more compact clusters\, such as three droplets in a triangular shape\, ou r results suggest that a non-uniform cross-sectional inflow profile is fur ther required. Overall\, the accelerated self-assembly of a small-size dro plet cluster results from the combined effects of strong depletion forces\ , shear alignments\, and fine-tuned inflow conditions. The deterministic n ature of the flow-assisted self-assembly implies large throughputs\, thoug h calibration of all effects is likely difficult at the same time.\n\nhttp s://lindico453.srv.lu.se/event/67/contributions/501/ LOCATION:Elite Hotel Ideon Tera URL:https://lindico453.srv.lu.se/event/67/contributions/501/ END:VEVENT BEGIN:VEVENT SUMMARY:Contr. Talk 9 - Poised between order and disorder: sheared DNA sol utions across the Isotropic-Nematic transition DTSTART;VALUE=DATE-TIME:20181211T134000Z DTEND;VALUE=DATE-TIME:20181211T140000Z DTSTAMP;VALUE=DATE-TIME:20260522T224733Z UID:indico-contribution-67-491@lindico453.srv.lu.se DESCRIPTION:Speakers: Giuliano Zanchetta (University of Milano)\nHydrogels built from DNA are an attractive class of materials\, whose structure and mechanical properties can be tuned by the design of “physical” cross- links based on selective Watson-Crick base pairing [Pan\, Soft Matter 12\, 5537 (2016)]. Even simple systems of entangled DNA helices can display com plex mechanical response\, such as shear banding [Boukany\, Soft Matter 5\ ,780 (2009)] and strain hardening [Orakdogen\, Macromolecules 43\, 1530 (2 010)]\; however\, in discussing such intriguing features\, it is often dis regarded that long DNA strands also undergo a transition to Nematic (N) li quid crystalline phase at concentrations as low as few mg/ml [Merchant\, B iophys.J. 73\,3154 (1997)].\nWe investigate the correlation among phase be haviour\, structure and rheological properties in DNA helices of thousands of base pairs. In a wide concentration range\, the solutions are viscoela stic while also displaying a continuous transition from Isotropic to N\, w ithout detectable phase separation. These solutions exhibit very low degre e of ordering at rest\, but strong\, transient birefringence when sheared. \nWe measure the mechanical and optical response to continuous\, oscillato ry and step deformations across the transition region. To this aim\, we co mbine rheology to real-space measurement of shear-induced alignment in a m icroscope shear cell\, or through polarized reflection directly on the rhe ometer [Mykhaylyk\, J. Polym. Sci. B 54\,2151 (2016)]. Furthermore\, throu gh rheo-SAXS experiments we gain access to the local degree of alignment a nd structure. \nWe find that both shear stress and birefringence relax wit h two different time scales\, a slow decay related to spontaneous disentan glement and a faster one\, which we interpret as the result of the frustra ted phase separation and local heterogeneity of the system. Regions with l arger N order are more easily aligned and fluidized than the isotropic\, v iscoelastic matrix in which they are embedded\, resulting in a faster opti cal and mechanical relaxation.\n\nhttps://lindico453.srv.lu.se/event/67/co ntributions/491/ LOCATION:Elite Hotel Ideon Tera URL:https://lindico453.srv.lu.se/event/67/contributions/491/ END:VEVENT BEGIN:VEVENT SUMMARY:Contr. Talk 8 - Shear Effects on Soft Colloids DTSTART;VALUE=DATE-TIME:20181211T103000Z DTEND;VALUE=DATE-TIME:20181211T105000Z DTSTAMP;VALUE=DATE-TIME:20260522T224733Z UID:indico-contribution-67-488@lindico453.srv.lu.se DESCRIPTION:Speakers: Jorg Stellbrink (JCNS-1\, Forschungszentrum Julich\, 52425 Julich\, Germany)\nWhereas the collective response to external shea r of soft colloids is frequently investigated [1\,2]\, observations of she ar-induced effects on the single particle level are still scarce. Therefor e we investigated this intraparticle “brush deformation” of polybutadi ene (PB) star and linear polymers by rheology and Rheo-SANS [3\, 4]. Excel lent agreement between experiment and theory with respect to the amount of shear deformation and shear thinning for star polymers with varying funct ionality\, f\, was found. Surprisingly\, two decay modes (“fast” and “slow” modes) were observed in flow curves of star polymers\, indicati ng a hierarchical deformation of the polymeric corona. In binary mixtures it was observed that fast and slow modes originating from the star polymer s were strongly affected by the addition of linear homopolymer\, which inf luenced the shear induced ‘brush deformation’ of star polymers. We fou nd macroscopic phase separation upon increasing concentrations of linear p olymer and shear-induced microphase separation (coil-to-globule transition ) by means of Rheo-SANS experiments.\n\nhttps://lindico453.srv.lu.se/event /67/contributions/488/ LOCATION:Elite Hotel Ideon Tera URL:https://lindico453.srv.lu.se/event/67/contributions/488/ END:VEVENT BEGIN:VEVENT SUMMARY:Keynote 6 - Nonlinear rheology of polydisperse blends of entangled linear polymers: Rolie-Double-Poly models DTSTART;VALUE=DATE-TIME:20181211T095000Z DTEND;VALUE=DATE-TIME:20181211T103000Z DTSTAMP;VALUE=DATE-TIME:20260522T224733Z UID:indico-contribution-67-487@lindico453.srv.lu.se DESCRIPTION:Speakers: Daniel Read (Department of Applied Mathematics\, Uni versity of Leeds\, UK)\nWhilst there has been much success in modeling the linear and nonlinear rheology of monodisperse entangled linear polymers\, progress in the constitutive modeling of polymeric materials continues to lag behind the needs of industry. Industrially sourced polymers are typic ally polydisperse (comprising a broad distribution of molecular weights)\, making their rheology more suitable for processing but also more difficul t to predict. To date\, there are no molecular-based constitutive models t hat are practically suitable for describing industrially relevant polymers in industrially relevant flows. We extend but strongly simplify the Read et al. model [Read et al.\, J.Rheol. 56\, 823-873 (2012)]\, which is able to predict the linear and nonlinear rheology of bidisperse blends but is p rohibitively complex for industrial use. We propose a pair of simplified t ube models for polydisperse melts of entangled linear polymers that combin e the success of the double reptation approximation [des Cloizeaux\, Europ hys. Lett. 5\, 437-442 (1988)] in the linear regime with the success of th e Rolie-Poly constitutive equation [Likhtman et al.\, J. Non-Newton. Fluid Mech.114\, 1-12 (2003)] in the nonlinear regime. For binary blends\, We s how that these models naturally identify the effects from couplings betwee n constraint release and chain retraction (i.e. the so-called "enhanced st retch relaxation time"). We generalize to a multi-component (polydisperse) model\, based on the same underlying principles. Both of our models are i n qualitative\, and largely quantitative\, agreement with experimental dat a for bidisperse and polydisperse melts of entangled linear polymers.\n\nh ttps://lindico453.srv.lu.se/event/67/contributions/487/ LOCATION:Elite Hotel Ideon Tera URL:https://lindico453.srv.lu.se/event/67/contributions/487/ END:VEVENT BEGIN:VEVENT SUMMARY:Contr. Talk 6 - Dynamics and morphological fingerprinting of nano- filled polymer systems subjected to nonlinear deformations DTSTART;VALUE=DATE-TIME:20181211T084000Z DTEND;VALUE=DATE-TIME:20181211T090000Z DTSTAMP;VALUE=DATE-TIME:20260522T224733Z UID:indico-contribution-67-485@lindico453.srv.lu.se DESCRIPTION:Speakers: Roland Kádár (Industrial and Materials Science\, E ngineering Materials\, Chalmers University of Technology\,)\nNonlinear def ormations are a key ingredient for applications of rheologically complex m aterials\,\ne.g. for the processing of polymeric materials stretching\, or ientation\, dissentaglement of\npolymer chains occurs\, with the interacti ons between flow field and constituents dictating the\noverall flow dynami cs and subsequent material properties/performance. In this framework\, we\ nfocus mainly on nano-filled suspensions and polymer composites in oscilla tory and steady\nshear for a various nanofillers\, e.g. graphene\, nanocel ulose etc.. Of particular importance is the\nanalysis of the oscillatory s hear stress output signal analysis in the framework of Fourier-\nTransform (FT) analysis and Tchebyshev polynomial decomposition. The effects of ori entation\ndynamics and morphological fingerprinting are highlighted\, with rheological percolation\nthresholds determined with superior sensitivity using nonlinear material parameters and\nnonlinear features hinting at the filler morphology of percolated network dynamic response.\n\nhttps://lind ico453.srv.lu.se/event/67/contributions/485/ LOCATION:Elite Hotel Ideon Tera URL:https://lindico453.srv.lu.se/event/67/contributions/485/ END:VEVENT BEGIN:VEVENT SUMMARY:Closing remarks DTSTART;VALUE=DATE-TIME:20181212T105000Z DTEND;VALUE=DATE-TIME:20181212T110000Z DTSTAMP;VALUE=DATE-TIME:20260522T224733Z UID:indico-contribution-67-479@lindico453.srv.lu.se DESCRIPTION:Speakers: Ann Terry (MAX IV)\nhttps://lindico453.srv.lu.se/eve nt/67/contributions/479/ LOCATION:Elite Hotel Ideon Tera URL:https://lindico453.srv.lu.se/event/67/contributions/479/ END:VEVENT BEGIN:VEVENT SUMMARY:Introduction to LINXS DTSTART;VALUE=DATE-TIME:20181210T121000Z DTEND;VALUE=DATE-TIME:20181210T123000Z DTSTAMP;VALUE=DATE-TIME:20260522T224733Z UID:indico-contribution-67-476@lindico453.srv.lu.se DESCRIPTION:Speakers: Stephen Hall (LINXS)\nhttps://lindico453.srv.lu.se/e vent/67/contributions/476/ LOCATION:Elite Hotel Ideon Tera URL:https://lindico453.srv.lu.se/event/67/contributions/476/ END:VEVENT BEGIN:VEVENT SUMMARY:Opening and Welcome DTSTART;VALUE=DATE-TIME:20181210T120000Z DTEND;VALUE=DATE-TIME:20181210T121000Z DTSTAMP;VALUE=DATE-TIME:20260522T224733Z UID:indico-contribution-67-475@lindico453.srv.lu.se DESCRIPTION:Speakers: Martin Trulsson (Theoretical Chemistry)\nhttps://lin dico453.srv.lu.se/event/67/contributions/475/ LOCATION:Elite Hotel Ideon Tera URL:https://lindico453.srv.lu.se/event/67/contributions/475/ END:VEVENT END:VCALENDAR