Nanoscale-Structured Hybrid Bragg Stacks with Orientation- and Composition-Dependent Mechanical and Thermal Transport Properties : Implications for Nacre Mimetics and Heat Management Applications

Title data

Dörres, Theresa ; Bartkiewicz, Malgorzata ; Herrmann, Kai ; Schöttle, Marius ; Wagner, Daniel ; Wang, Zuyuan ; Ikkala, Olli ; Retsch, Markus ; Fytas, George ; Breu, Josef:
Nanoscale-Structured Hybrid Bragg Stacks with Orientation- and Composition-Dependent Mechanical and Thermal Transport Properties : Implications for Nacre Mimetics and Heat Management Applications.
In: ACS Applied Nano Materials. Vol. 5 (2022) Issue 3 . - pp. 4119-4129.
ISSN 2574-0970
DOI: https://doi.org/10.1021/acsanm.2c00061

Official URL:

Abstract in another language

Layered nanomaterials fascinate researchers for their mechanical, barrier, optical, and transport properties. Nacre is a biological example thereof, combining excellent mechanical properties by aligned submicron inorganic platelets and nanoscale proteinic interlayers. Mimicking nacre with advanced nanosheets requires ultraconfined organic layers aimed at nacre-like high reinforcement fractions. We describe inorganic/polymer hybrid Bragg stacks with one or two fluorohectorite clay layers alternating with one or two poly(ethylene glycol) layers. As indicated by X-ray diffraction, perfect one-dimensional crystallinity allows for homogeneous single-phase materials with up to a 84% clay volume fraction. Brillouin light spectroscopy allows the exploration of ultimate mechanical moduli without disturbance by flaws, suggesting an unprecedentedly high Young's modulus of 162 GPa along the aligned clays, indicating almost ideal reinforcement under these conditions. Importantly, low heat conductivity is observed across films, kappa(perpendicular to) = 0.11-0.15 W m(-1) K-1, with a high anisotropy of kappa(parallel to)/kappa(perpendicular to) = 28-33. The macroscopic mechanical properties show ductile-to-brittle change with an increase in the clay volume fraction from 54% to 70%. Conceptually, this work reveals ultimate elastic and thermal properties of aligned layered clay nanocomposites in flaw-tolerant conditions.

Further data

Item Type:	Article in a journal
Refereed:	Yes
Keywords:	organic-inorganic nanocomposites; Brillouin light spectroscopy; thermal conductivity; mechanical tensor; nacre mimetic; LAYERED NANOCOMPOSITES; MONTMORILLONITE; ULTRASTRONG; STRENGTH, MODULUS; MATRIX; TOUGH; FILMS
Institutions of the University:	Faculties > Faculty of Biology, Chemistry and Earth Sciences > Department of Chemistry > Chair Inorganic Chemistry I > Chair Inorganic Chemistry I - Univ.-Prof. Dr. Josef Breu Faculties Faculties > Faculty of Biology, Chemistry and Earth Sciences Faculties > Faculty of Biology, Chemistry and Earth Sciences > Department of Chemistry Faculties > Faculty of Biology, Chemistry and Earth Sciences > Department of Chemistry > Chair Inorganic Chemistry I
Result of work at the UBT:	Yes
DDC Subjects:	500 Science > 540 Chemistry
Date Deposited:	04 Oct 2022 12:44
Last Modified:	20 Oct 2022 07:41
URI:	https://eref.uni-bayreuth.de/id/eprint/72188