Fine structure and optical properties of cholesteric films prepared from cellulose 4-methylphenyl urethane/ N-vinyl pyrrolidinone solutions

Valeria Arrighi, John Mackenzie Grant Cowie, Paz Vaqueiro, K. A. Prior

Research output: Contribution to journalArticle

Abstract

Solutions of 4-methylphenylurethane of cellulose in N-vinyl pyrrolidinone have been investigated, and a cholesteric mesophase was found above a concentration of 35 wt % of polymer. The selective reflection of light from the cholesteric solutions lies in the visible region of the spectrum and moves from blue toward red with increasing temperature. After photopolymerization of these solutions, solid opalescent films, which conserve the cholesteric order of the lyotropic phase, can be prepared. The fine structure of these colored films has been investigated by scanning electron microscopy (SEM) and atomic force microscopy (AFM). In the fractured surfaces of the films, a periodic lamellar structure, which may arise from the helically twisted structure of the cholesteric mesophase, is observed. The periodicity of the lamellar structure is in good agreement with the calculated value of half a pitch of the cholesteric helix.
Original languageEnglish
Pages (from-to)7354-7360
Number of pages7
JournalMacromolecules
Volume35
Issue number19
DOIs
Publication statusPublished - 10 Sep 2002

Fingerprint

Pyrrolidinones
Urethane
Cellulose
Lamellar structures
Optical properties
Photopolymerization
Solid solutions
Atomic force microscopy
Polymers
Scanning electron microscopy
Temperature

Cite this

@article{bac2bc6d70a0433cb0251bcb33bfd04d,
title = "Fine structure and optical properties of cholesteric films prepared from cellulose 4-methylphenyl urethane/ N-vinyl pyrrolidinone solutions",
abstract = "Solutions of 4-methylphenylurethane of cellulose in N-vinyl pyrrolidinone have been investigated, and a cholesteric mesophase was found above a concentration of 35 wt {\%} of polymer. The selective reflection of light from the cholesteric solutions lies in the visible region of the spectrum and moves from blue toward red with increasing temperature. After photopolymerization of these solutions, solid opalescent films, which conserve the cholesteric order of the lyotropic phase, can be prepared. The fine structure of these colored films has been investigated by scanning electron microscopy (SEM) and atomic force microscopy (AFM). In the fractured surfaces of the films, a periodic lamellar structure, which may arise from the helically twisted structure of the cholesteric mesophase, is observed. The periodicity of the lamellar structure is in good agreement with the calculated value of half a pitch of the cholesteric helix.",
author = "Valeria Arrighi and Cowie, {John Mackenzie Grant} and Paz Vaqueiro and Prior, {K. A.}",
year = "2002",
month = "9",
day = "10",
doi = "10.1021/ma012098n",
language = "English",
volume = "35",
pages = "7354--7360",
journal = "Macromolecules",
issn = "0024-9297",
publisher = "American Chemical Society",
number = "19",

}

Fine structure and optical properties of cholesteric films prepared from cellulose 4-methylphenyl urethane/ N-vinyl pyrrolidinone solutions. / Arrighi, Valeria; Cowie, John Mackenzie Grant; Vaqueiro, Paz; Prior, K. A.

In: Macromolecules, Vol. 35, No. 19, 10.09.2002, p. 7354-7360.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Fine structure and optical properties of cholesteric films prepared from cellulose 4-methylphenyl urethane/ N-vinyl pyrrolidinone solutions

AU - Arrighi, Valeria

AU - Cowie, John Mackenzie Grant

AU - Vaqueiro, Paz

AU - Prior, K. A.

PY - 2002/9/10

Y1 - 2002/9/10

N2 - Solutions of 4-methylphenylurethane of cellulose in N-vinyl pyrrolidinone have been investigated, and a cholesteric mesophase was found above a concentration of 35 wt % of polymer. The selective reflection of light from the cholesteric solutions lies in the visible region of the spectrum and moves from blue toward red with increasing temperature. After photopolymerization of these solutions, solid opalescent films, which conserve the cholesteric order of the lyotropic phase, can be prepared. The fine structure of these colored films has been investigated by scanning electron microscopy (SEM) and atomic force microscopy (AFM). In the fractured surfaces of the films, a periodic lamellar structure, which may arise from the helically twisted structure of the cholesteric mesophase, is observed. The periodicity of the lamellar structure is in good agreement with the calculated value of half a pitch of the cholesteric helix.

AB - Solutions of 4-methylphenylurethane of cellulose in N-vinyl pyrrolidinone have been investigated, and a cholesteric mesophase was found above a concentration of 35 wt % of polymer. The selective reflection of light from the cholesteric solutions lies in the visible region of the spectrum and moves from blue toward red with increasing temperature. After photopolymerization of these solutions, solid opalescent films, which conserve the cholesteric order of the lyotropic phase, can be prepared. The fine structure of these colored films has been investigated by scanning electron microscopy (SEM) and atomic force microscopy (AFM). In the fractured surfaces of the films, a periodic lamellar structure, which may arise from the helically twisted structure of the cholesteric mesophase, is observed. The periodicity of the lamellar structure is in good agreement with the calculated value of half a pitch of the cholesteric helix.

UR - http://www.scopus.com/inward/record.url?scp=0037056272&partnerID=8YFLogxK

U2 - 10.1021/ma012098n

DO - 10.1021/ma012098n

M3 - Article

VL - 35

SP - 7354

EP - 7360

JO - Macromolecules

JF - Macromolecules

SN - 0024-9297

IS - 19

ER -