Title: Robust Chiral Organization of Cellulose Nanocrystals in Capillary Confinement

Abstract

Here we showed large area uniformly aligned chiral photonic bioderived films from a liquid crystal phase formed by a cellulose nanocrystal (CNC) suspension placed in a thin capillary. As a result of the spatial confinement of the drying process, the interface between coexisting isotropic and chiral phases aligns perpendicular to the long axis of the capillary. This orientation facilitates a fast homogeneous growth of chiral pseudolayers parallel to the interface. Overall, the formation of organized solids takes hours vs weeks in contrast to the slow and heterogeneous process of drying from the traditional dish-cast approach. The saturation of water vapor in one end of the capillary causes anisotropic drying and promotes unidirectional propagation of the anisotropic phase in large regions that results in chiral CNC solid films with a uniformly oriented layered morphology. Corresponding ordering processes were monitored in situ at a nanoscale, mesoscale, and microscopic scale with complementary scattering and microscopic techniques. The resulting films show high orientation order at a multilength scale over large regions and preserved chiral handedness causing a narrower optical reflectance band and uniform birefringence over macroscopic regions in contrast to traditional dish-cast CNC films and those assembled in a magnetic field and on porousmore » substrates. Finally, these thin films with a controllable and well-identified uniform morphology, structural colors, and handedness open up interesting possibilities for broad applications in bioderived photonic nanomaterials.« less

Authors:

Cherpak, V. ^[1]; Korolovych, V. F. ^[1]; Geryak, R. ^[1]; Turiv, T. ^[2]; Nepal, D. ^[3]; Kelly, J. ^[3]; Bunning, T. J. ^[3]; Lavrentovich, O. D. ^[4]; Heller, W. T.  ^[5];

• Search DOE PAGES for author "Heller, W. T."
• Search DOE PAGES for ORCID "0000-0001-6456-2975"

Tsukruk, V. V.  ^[1]

• Search DOE PAGES for author "Tsukruk, V. V."
• Search DOE PAGES for ORCID "0000-0001-5489-0967"

---

+ Show Author Affiliations

1. Georgia Inst. of Technology, Atlanta, GA (United States). School of Materials Science and Engineering
2. Kent State Univ., Kent, OH (United States). Liquid Crystal Inst. Chemical Physics Interdisciplinary Program
3. Air Force Research Lab. (AFRL), Wright-Patterson AFB, OH (United States). Materials and Manufacturing Directorate
4. Kent State Univ., Kent, OH (United States). Liquid Crystal Inst. Chemical Physics Interdisciplinary Program. Dept. of Physics
5. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Neutron Scattering Division

Publication Date:

Tue Oct 23 00:00:00 EDT 2018

Research Org.:

Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Air Force Research Lab. (AFRL), Wright-Patterson AFB, OH (United States); Georgia Institute of Technology, Atlanta, GA (United States)

Sponsoring Org.:

USDOE Office of Science (SC); US Air Force Office of Scientific Research (AFOSR); National Science Foundation (NSF)

OSTI Identifier:

1484100

Grant/Contract Number:  

AC05-00OR22725; FA8650-D-16-5404; FA9550-17-1-0297; CBET 1803495

Resource Type:

Accepted Manuscript

Journal Name:

Nano Letters

Additional Journal Information:

Journal Volume: 18; Journal Issue: 11; Journal ID: ISSN 1530-6984

Publisher:

American Chemical Society

Country of Publication:

United States

Language:

English

Subject:

36 MATERIALS SCIENCE; 37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; cellulose nanocrystals; chiral nematic formation; liquid crystal phase; real-time monitoring