Dataset Information

From Structure to Properties of Composite Films Derived from Cellulose Nanocrystals.

ABSTRACT: Many natural materials exhibit a multilayer structure in which adjacent layers rotate in a helicoidal manner. The remarkable optical and mechanical properties of these materials have motivated research and development of man-made materials with similar morphology. Among them, composite materials by cellulose nanocrystals (CNCs) and polymers have attracted great interest; however, the relationship between the cholesteric structure and the material properties is not well understood. We used the composite CNC-polymer latex films with random, stratified, and cholesteric morphologies, all with the same compositions, to explore the effect of structure on the optical and mechanical properties of the composite films. Films with a cholesteric structure exhibited strong extinction, circular dichroism, and high stiffness; however, they had lower toughness than the films with the cholesteric stratified morphology. Films with disordered morphologies exhibited the highest toughness and the lowest stiffness. These trends were attributed to the confinement effects and the difference in polymer distribution in the films. These results provide guidance for the preparation of biomimetic cholesteric films with targeted optical and mechanical properties.

SUBMITTER: Vollick B

PROVIDER: S-EPMC6644686 | biostudies-literature | 2017 Sep

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

From Structure to Properties of Composite Films Derived from Cellulose Nanocrystals.

Vollick Brandon B Kuo Pei-Yu PY Alizadehgiashi Moien M Yan Ning N Kumacheva Eugenia E

ACS omega 20170919 9

Many natural materials exhibit a multilayer structure in which adjacent layers rotate in a helicoidal manner. The remarkable optical and mechanical properties of these materials have motivated research and development of man-made materials with similar morphology. Among them, composite materials by cellulose nanocrystals (CNCs) and polymers have attracted great interest; however, the relationship between the cholesteric structure and the material properties is not well understood. We used the co ...[more]

PMID: 31457846

Similar Datasets

Project description:The study was used in the context of realigning novel low-cost materials for their better and improved optical properties. Emphasis was placed on the bio-nanocomposite approach for producing cellulose/starch/silver nanoparticle films. These polymeric films were produced using the solution casting technique followed by the thermal evaporation process. The structural model of the bio-composite films (CS:CL-CNC7:3-50%) was developed from our previous study. Subsequently, in order to improve the optical properties of bio-composite films, bio-nanocomposites were prepared by incorporating silver nanoparticles (AgNPs) ex situ at various concentrations (5-50% w/w). Characterization was conducted using UV-Visible (UV-Vis), Fourier Transform Infrared (FTIR), Scanning Electron Microscope (SEM) and Transmission Electron Microscope (TEM) to understand the structure-property relationships. The FTIR analysis indicated a reduction in the number of waves associated with the OH functional groups by adding AgNPs due to the formation of new hydrogen bonds between the bio-composite matrix and the CL-WE-AgNPs. Based on mathematical equations, the optical bandgap energy, the energy of Urbach, the edge of absorption (Ed), and the carbon clusters (N) were estimated for CS:CL-CNC and CS:CL-CNC-AgNPs (5-50%) nanocomposite films. Furthermore, the optical bandgap values were shifted to the lower photon energy from 3.12 to 2.58 eV by increasing the AgNPs content, which indicates the semi-conductor effect on the composite system. The decrease in Urbach's energy is the result of a decrease in the disorder of the biopolymer matrix and/or attributed to an increase in crystalline size. In addition, the cluster carbon number increased from 121.56 to 177.75, respectively, from bio-composite to bio-nanocomposite with 50% AgNPs. This is due to the presence of a strong H-binding interaction between the bio-composite matrix and the AgNPs molecules. The results revealed that the incorporation of 20% AgNPs into the CS:CL-CNC7:3-50% bio-composite film could be the best candidate composition for all optical properties. It can be used for potential applications in the area of food packaging as well as successfully on opto-electronic devices.

Dataset Information

From Structure to Properties of Composite Films Derived from Cellulose Nanocrystals.

Publications

From Structure to Properties of Composite Films Derived from Cellulose Nanocrystals.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets