Journal De Physique Ii最新文献_第3页

Study of the α-Mechanical Relaxation in Molecular Glass-Forming Liquids 分子玻璃形成液中α-机械弛豫的研究

Journal De Physique Ii Pub Date : 1997-11-01 DOI: 10.1051/JP2:1997207

A. Faivre, L. David, J. Pérez

引用次数: 8

Modification of the Lamellar Phase in C12E5/Water System by a Random Hydrophilic-Hydrophobic Polyelectrolyte 随机亲疏水聚电解质对C12E5/水体系片层相的改性

Journal De Physique Ii Pub Date : 1997-10-01 DOI: 10.1051/JP2:1997193

E. Z. Radlinska, T. Gulik‐Krzywicki, F. Lafuma, D. Langevin, W. Urbach, C. Williams

{"title":"Modification of the Lamellar Phase in C12E5/Water System by a Random Hydrophilic-Hydrophobic Polyelectrolyte","authors":"E. Z. Radlinska, T. Gulik‐Krzywicki, F. Lafuma, D. Langevin, W. Urbach, C. Williams","doi":"10.1051/JP2:1997193","DOIUrl":"https://doi.org/10.1051/JP2:1997193","url":null,"abstract":"The microstructure of a ternary system of a non-ionic surfactant (n–dodecyl pentaoxyethylene glycol ether, C12E5), water and a water-soluble random heteropolymer, poly (styrene-r-Na styrene sulfonate) with degrees of sulfonation ranging from 30% to 90% is investigated at room temperature. Using small angle X-ray scattering and freeze-fracture electron microscopy we focus on the lamellar phase region and study samples along four different paths of constant surfactant-to-water ratio with increasing polymer content. We demonstrate that for samples with low water content (S/W ratios 3.4 and 4.9), regardless of the sulfonation degree of the polymer, the lamellar phase persists up to several weight percent of polymer and the polymer molecules are confined inside the surfactant bilayers. With increasing quantity of polymer the lamellar phase Bragg peak shifts in a manner consistent with the increase of the lamellar period, which indicates increased bilayer thickness. For mixtures less concentrated in surfactant first order phase transitions are observed for all polymer charge contents when the amount of polymer is increased. For low charge contents of polymer (30% and 45%) the lamellar stack of the polymer-doped surfactant bilayers coexists with either cubic or another lamellar phase and microscopic phase separation is only observed. For large charge contents (65% and 90%) a surfactant-rich lamellar phase coexists with a polymer-rich water solution. It is suggested that the observed phase behaviour is governed by the concentration number of free water molecules.","PeriodicalId":14774,"journal":{"name":"Journal De Physique Ii","volume":"29 1","pages":"1393-1416"},"PeriodicalIF":0.0,"publicationDate":"1997-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76686255","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 15

Contact Force Distribution Beneath a Three-Dimensional Granular Pile 三维颗粒桩下的接触力分布

Journal De Physique Ii Pub Date : 1997-10-01 DOI: 10.1051/JP2:1997200

R. Brockbank, J. M. Huntley, J. M. Huntley, R. Ball

引用次数: 101

What about the Backbone Conformation in Nematic and Smectic C Phases of a ``Side-on'' Fixed LCP? A SANS Study “侧对”固定LCP的向列相和密聚C相的主干构象是怎样的?SANS研究

Journal De Physique Ii Pub Date : 1997-10-01 DOI: 10.1051/JP2:1997194

S. Lecommandoux, L. Noirez, M. Achard, F. Hardouin

引用次数: 10

Kelvin-Helmholtz instability of Langmuir monolayers Langmuir单层膜的Kelvin-Helmholtz不稳定性

Journal De Physique Ii Pub Date : 1997-10-01 DOI: 10.1051/JP2:1997189

S. Komura, T. Iwayama

引用次数: 2

Is the electromechanical coupling the driving force for the perpendicular drift of first class cholesteric finger 机电耦合是一级胆甾指垂直漂移的驱动力吗

Journal De Physique Ii Pub Date : 1997-10-01 DOI: 10.1051/JP2:1997198

L. Gil, S. Thiberge

引用次数: 8

Modification of the Crystallization Kinetics of a Mixed Bath of Alkanes in the Presence of Coil-Crystalline Block Copolymer Micelles 盘状嵌段共聚物胶束存在下烷烃混合浴结晶动力学的改变

Journal De Physique Ii Pub Date : 1997-10-01 DOI: 10.1051/JP2:1997192

D. Buzza, T. McLeish

{"title":"Modification of the Crystallization Kinetics of a Mixed Bath of Alkanes in the Presence of Coil-Crystalline Block Copolymer Micelles","authors":"D. Buzza, T. McLeish","doi":"10.1051/JP2:1997192","DOIUrl":"https://doi.org/10.1051/JP2:1997192","url":null,"abstract":"Recent Neutron Scattering experiments by Richter et al. [1] show that the presence of coil-crystalline block copolymer (PE-PEP) micelles in a mixed alkane bath suppresses the crystallization out of solution of the long alkane component at low temperatures. Motivated by these experiments, we study theoretically the thermodynamics and kinetics of lamellar coil-crystalline block copolymer micelles in a bimodal solvent to better understand the factors determining the anti-precipitation action of coil-crystalline block copolymers. We assume an Alexander-de Gennes brush model for the strongly stretched corona chains and explicitly account for the polydispersity of the solvent chains. For the thermodynamic distribution of solvent chains in the corona, we find a predominance of short solvent chains to long solvent chains in the corona phase compared to the solvent bath, both with and without nematic interactions in the corona phase. We also calculate the rate of crystallization of the long solvent chains onto the micellar crystal core and find that the rate is sensitive to both brush and core parameters. In particular, we predict that to maximize the rate, both E fold /kTN A and X n need to be made as small as possible, where E fold is the folding energy of the crystal core chains, N A the number of statistical segments of the solvated corona chains and X n parameterises the strength of nematic interactions in the micellar corona. This leads to the surprising result that for fixed E fold , the rate of crystallization is increased when we increase the molecular weight of the corona blocks.","PeriodicalId":14774,"journal":{"name":"Journal De Physique Ii","volume":"35 1","pages":"1379-1392"},"PeriodicalIF":0.0,"publicationDate":"1997-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90967175","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 3

A Single Director Switching Mode for Monodomain Liquid Crystal Elastomers 单畴液晶弹性体的单导开关模式

Journal De Physique Ii Pub Date : 1997-10-01 DOI: 10.1051/JP2:1997190

P. M. Roberts, G. Mitchell, F. Davis

{"title":"A Single Director Switching Mode for Monodomain Liquid Crystal Elastomers","authors":"P. M. Roberts, G. Mitchell, F. Davis","doi":"10.1051/JP2:1997190","DOIUrl":"https://doi.org/10.1051/JP2:1997190","url":null,"abstract":"We report rotation of a single director in a nematic monodomain, acrylate based side-chain elastomer which was subjected to mechanical fields applied at angles in the range 80° 90° to the director, no, present at the time of network formation. Time and spatially resolving wide angle X-ray scattering, together with polarised light microscopy measurements revealed a pronounced, almost discontinuous switching mode at a critical extension as the strain was applied at angles approaching 90° to no, whereas a more continuous rotation was seen when the strain was applied at more acute angles. This director reorientation was more or less uniform across the complete sample and was accompaniecl by a modest decrease in orientation parameter (P2). At strains sufficient to induce switching there was some continuous distribution of director orientations with fluctuations of +10° although there was no evidence for any localised director inhomogenities such as domain formation. The observed deformation behaviour of these acrylate-based nematic monodomains was in accord with the predictions of a theory developed by Bladon et al., in that the complete set of data could be accounted for through a single parameter describing the chain anisotropy. The experimentally deduced chain anisotropy parameter was in broad agreement with that obtained from small-angle neutron scattering procedures, but was somewhat greater than that obtained by spontaneous shape changes at the nematic-isotropic transition.","PeriodicalId":14774,"journal":{"name":"Journal De Physique Ii","volume":"16 1","pages":"1337-1351"},"PeriodicalIF":0.0,"publicationDate":"1997-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77358499","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 19

Surface Effects on Block Copolymer Melts Above the Order-Disorder Transition: Linear Theory of Equilibrium Properties and the Kinetics of Surface-Induced Ordering 嵌段共聚物熔体在有序-无序过渡之上的表面效应:平衡性质的线性理论和表面诱导有序的动力学

Journal De Physique Ii Pub Date : 1997-10-01 DOI: 10.1051/JP2:1997191

K. Binder, Harry L. Risch, S. Stepanow

{"title":"Surface Effects on Block Copolymer Melts Above the Order-Disorder Transition: Linear Theory of Equilibrium Properties and the Kinetics of Surface-Induced Ordering","authors":"K. Binder, Harry L. Risch, S. Stepanow","doi":"10.1051/JP2:1997191","DOIUrl":"https://doi.org/10.1051/JP2:1997191","url":null,"abstract":"A phenomenological theory is developed for static and dynamic aspects ofsurface- induced ordering of symmetrical block copolymers taking fluctuation corrections into account, but, considering conditions where the bulk block copolymer melt is still disordered, and a lin- earized version of the resulting Ginzburg-Landau type equation suffices. Both the semi-infinite geometry and symmetrical films of thickness 2L are treated, applying the same boundary con- ditions as used previously for a treatment of wetting in polymer blends, assuming short range surface forces and a long Wavelength approximation. For the static order parameter profile in thin film geometry, We derive an oscillatory convergence of both amplitude and phase to the corre- sponding properties of the semi-infinite systems, because terms of order exp(-2L/f+) cos(2Lq*) enter, f+ being the correlation length and = 21r/q* the Wave~length of lamellar ordering. It is shown that the conservation of the number of monomers of the two species, Which can be expressed as a global constraint on the order parameter, leads to a non-linear equation for the phase expressed in terms of the amplitude, When one considers the kinetics of ordering. Both numerical and approximate analytical treatments are given to describe the evolution of the considered systems towards equilibrium.","PeriodicalId":14774,"journal":{"name":"Journal De Physique Ii","volume":"7 1","pages":"1353-1378"},"PeriodicalIF":0.0,"publicationDate":"1997-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76272578","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 11

Standing Wave Localized Squares in Pattern-Forming Nonequilibrium Systems 非平衡系统中的驻波定域方阵

Journal De Physique Ii Pub Date : 1997-10-01 DOI: 10.1051/JP2:1997188

H. Sakaguchi, H. Brand

引用次数: 3