Mesophase formation by semirigid polymers: poly(n-hexyl isocyanate) in dichloromethane and toluene

Conio, G.; Bianchi, E.; Ciferri, A.; Krigbaum, W. R.

doi:10.1021/ma00134a054

Cited by 56 publications

(35 citation statements)

References 8 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The C * values for the toluene solutions of PS-1, PS-100, PHIC-3, and PHIC-15 were 1.0, 0.04, 0.065, and 0.014 g/100 mL, respectively (9,10). Moreover, PS and PHIC chains could not be adsorbed onto the silica surface from their toluene solutions.…”

Section: Samplesmentioning

confidence: 95%

See 1 more Smart Citation

Polymer Depletion-Induced Instability of Silica Suspensions in the Presence of Flexible and Semiflexible Polymers

Yamazaki

Kawaguchi

Kato

2002

Journal of Colloid and Interface Science

View full text Add to dashboard Cite

Section: Samplesmentioning

confidence: 95%

“…The radii of gyration of PS-1, PS-100, PHIC-3, and PHIC-100 in toluene were determined to be 3.1, 48, 12, and 34 nm, respectively (9,10). The persistence length of PHIC is 37 nm and PHIC samples correspond to semiflexible polymers (10).…”

Section: Samplesmentioning

confidence: 99%

Polymer Depletion-Induced Instability of Silica Suspensions in the Presence of Flexible and Semiflexible Polymers

Yamazaki

Kawaguchi

Kato

2002

Journal of Colloid and Interface Science

View full text Add to dashboard Cite

“…., vious observations with this polymer by Berger and Tidswell 8 and Conio et al 7 The double-logarithmic plots of [17] against…”

Section: 5 ------------------mentioning

confidence: 98%

“…Conio et a!. 7 reported q values of 38 and 19nm for PHIC in toluene of 25°C and in DCM of 20°C, respectively, which were obtained by analyzing their [I'/] data with Mv based on the Berger-Tidswell viscosity relationship for toluene solutions; they used a d value of 1 .03 nm obtained from vP of PHIC and with ML assumed to be 635 nm -i. However, the excellent agreement of their q values with ours is accidental, because the latter viscosity relationship does not agree with ours.…”

Section: Mwmentioning

confidence: 99%

Wormlike Chain Parameters of Poly(hexyl isocyanate) in Dilute Solution

Itou

Chikiri

Teŕamoto

et al. 1988

Polym J

View full text Add to dashboard Cite

ABSTRACT:Intrinsic viscosity-molecular weight relationships were determined for poly(hexyl isocyanate) in toluene and dichloromethane using a number of narrow-distribution samples covering ·a wide molecular weight range. The data were analyzed according to the YamakawaFujii-Y oshizaki theory of viscosity of wormlike cylinders, yielding the following values for the persistence length q and molar mass ML per unit contour length: q=41-34nm and ML =730-760 nm-1 in toluene between 10 and 40°C and q=2lnm and ML=750nm-1 in dichloromethane at 20°C. These parameter values are favorably compared with those reported for other solvent conditions for the same polymer.KEY WORDS Poly(hexyl isocyanate) / Wormlike Chain / Persistence Length/ Yamakawa-Fujii-Yoshizaki Theory/ Chain Stiffness/ Stiff Chain/ Intrinsic Viscosity /

show abstract

“…24 Aharoni and Walsh 19 • 20 and Conio et a/. 22 studied the phase separation of the solutions of these A single sample or combinations of more than two samples with different molecular weights, all polydisperse, were used and significant molecular weight fractionation was found to occur on phase separation. They have taken these findings to substantiate the validity of the theories for polydisperse rods.…”

Section: Data For Other Rod/ike Polymersmentioning

confidence: 99%

Multi-Phase Equilibrium in Aqueous Solutions of the Triple-Helical Polysaccharide, Schizophyllan

Itou

Teŕamoto

1984

Polym J

View full text Add to dashboard Cite

ABSTRACT:Ternary phase diagrams were determined at 25oC for aqueous solutions of a rodlike polysaccharide schizophyllan, using three fractionated samples of different axial ratios x: sample T-3, x=223; sample 36.8; 18.3. Two ternary systems UR-28+ T-3 +water and U-110+ T-3+water were investigated. The phase diagram of either system was occupied by a wide biphasic region, where a dilute isotropic phase and concentrated cholesteric phase coexisted at equilibrium. The phase diagram of the system U-110 + T-3 +water contained two addftional regions, one where two cholesteric phases and one isotropic phase coexisted at equilibrium and the other where two cholesteric phases coexisted. A remarkable molecular weight fractionation took place on phase separation, and the larger x component was almost excluded from the dilute phase (or phases). All these features of the phase diagrams were consistent with the theoretical prediction by Abe and Flory for athermal ternary solutions. Quantitative agreement between theory and experiment was far from satisfactory, although the disagreement was considerably diminished when the interaction parameter was incorporated into the Abe-Flory theory.KEY WORDS Phase Equilibrium I Ternary System I Rodlike Polymer I Polysaccharide I Molecular Weight Fractionation I Triphase Separation I Cholesteric Liquid Crystal I Schizophyllan I Recently, we have been interested in aqueous solutions of the polysaccharide, schizophyllan, 1 -4 which exists as a trimer forming a rigid straight helix in water. 5 • 6 One purpose of these studies has been to investigate the phase behavior of solutions of rodlike polymers with schizophyllan as a model substance. Aqueous schizophyllan shows various interesting characteristics of rodlike polymers. Indeed, it forms a cholesteric mesophase above a certain critical concentration, and there is a concentration range where the isotropic and cholesteric phases coexist at equilibrium. 1 -3 Detailed experimental data for this equilibrium compare favorably with existing theories of rodlike polymers 7 -g in qualitative terms, although a quantitative agreement between theory and experiment has not yet been achieved. 3 It was shown in a preliminary paper 10 that an aqueous solution of two fractionated samples at appropriate composition separated into three phases at equilibrium: an isotropic phase and two cholesteric phases. This may be the first evidence for the theory of Abe and Flory 11 on ternary systems of two rodlike polymers in a single solvent. This theory as well as many others is formulated for monodisperse polymers, but most of the experimental systems consist of polydisperse polymers. As has been predicted theoretically 7 -9 • 11 -15 and confirmed experimentally, 3 • 16 -22 the phase behavior of a given system depends on the molecular weight of the polymer solute, and hence on the molecular weight distribution for a polydisperse solute. Therefore, any experimental test of the theories cannot be conclusive unless due attention is paid on the samples' polydispersity...

show abstract

Mesophase formation by semirigid polymers: poly(n-hexyl isocyanate) in dichloromethane and toluene

Cited by 56 publications

References 8 publications

Polymer Depletion-Induced Instability of Silica Suspensions in the Presence of Flexible and Semiflexible Polymers

Polymer Depletion-Induced Instability of Silica Suspensions in the Presence of Flexible and Semiflexible Polymers

Wormlike Chain Parameters of Poly(hexyl isocyanate) in Dilute Solution

Multi-Phase Equilibrium in Aqueous Solutions of the Triple-Helical Polysaccharide, Schizophyllan

Contact Info

Product

Resources

About