Solvent triggered irreversible shape morphism of biopolymer films

Rath, Amrita; Geethu, P. M.; Mathesan, Santhosh; Satapathy, Dillip K.; Ghosh, Pijush

doi:10.1039/c8sm00042e

Cited by 27 publications

(16 citation statements)

References 34 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The cross-linker molecules link the polymer chain segments by forming covalent bonds, leading to three-dimensional networks. An increase in the film stiffness and a reduction in the segmental mobility of the chains, upon crosslinking, are well established for chitosan. , Therefore, a shift of the P g to a higher R H value is expected for cross-linked chitosan thin films as higher osmotic pressure will be required to boost the segmental mobility.…”

Section: Resultsmentioning

confidence: 99%

Penetrant-Induced Glass-like Transition in Thin Chitosan Films

et al. 2021

Self Cite

View full text Add to dashboard Cite

We present the water vapor-induced swelling and the emergence of a penetrant-induced glass-like transition in the substrate-supported glassy chitosan thin films. The time evolution of the film thickness under different levels of relative humidity conditions is measured in real-time using a spectroscopic ellipsometer equipped with a humidity cell. In a dry film, the network of chitosan chains is in a glassy state, and upon exposure to water vapor, initially, the film swells by Fickian diffusion of water molecules, which triggers the structural relaxations of the chains. Under higher humidity conditions, a relatively slower evolution of thickness succeeds the initial rapid swelling due to the non-Fickian sorption of water molecules. The swelling characteristics of the polymer films are accounted for by considering the diffusion−relaxation mechanism of chains in the presence of smaller penetrant molecules. The penetrant-induced glass-like transition (P g ), where the polymer film isothermally transits from a glassy to a rubbery state, is determined for pristine and cross-linked chitosan films. P g is determined from the abrupt change in the rate of swelling observed upon increasing the relative humidity. Chemical crosslinking has an evident influence on the penetrant-induced glass-like transition of the chitosan films. P g was found to rise sharply for stiffer films with higher cross-linking density.

show abstract

Section: Resultsmentioning

confidence: 99%

Penetrant-Induced Glass-like Transition in Thin Chitosan Films

et al. 2021

Self Cite

View full text Add to dashboard Cite

show abstract

“…While the observed upward bending of the silk fibroin film upon exposure to water vapor can be comprehended by considering the well-established vapor absorption-induced differential swelling of the film leading to a stress gradient across the thickness, ,− the downward bending upon alcohol vapor exposure is still puzzling. In a similar foot, is it possible that the downward bending upon exposure to alcohol vapor arises from the desorption of water molecules from the silk fibroin film leading to a differential contraction of the film?…”

Section: Resultsmentioning

confidence: 99%

Bidirectional Actuation of Silk Fibroin Films: Role of Water and Alcohol Vapors

2022

Self Cite

View full text Add to dashboard Cite

shape morphism observed in nature inspires the development of stimuli-responsive soft actuators. Vapor-responsive actuators are promising among the different stimuli-responsive materials due to their capability to produce macroscale movements in response to a minuscule amount of specific chemical vapor. Here, we report unusual multiple vapor-responsive bidirectional macroscale actuation behaviors of single-layer regenerated silk fibroin films. The vaporresponsive silk fibroin actuator exhibits antagonistic actuation characteristics in a reversible manner to both water and ethanol vapors. For instance, it produces an upward bending in the presence of water vapor and downward bending in ethanol vapor, which demonstrates the chemical vapor-specific actuation. However, the actuation characteristics remain largely invariant upon changing the polarity of alcohol molecules. The silk fibroin actuators effectively utilize the vapor-induced minuscule expansion and contraction of the film surface to produce large-scale actuation, which is fully reversible. The intrinsic water content of the films and the vapor pressure of the stimulants are exploited to control the actuation performance. Further, we demonstrated the 3D shape morphing ability of the actuator by generating an undulating wavelike motion via preprogrammed water and ethanol vapor exposure conditions. The change in the actuation direction is instantaneous, which ensures the sensitivity and rapid response of the fabricated actuators.

show abstract

“…Ghosh et al . reported a cross‐linked chitosan film which can fold and unfold reversibly or irreversibly at various ratios of aromatic alcohols.…”

Section: Actuating Behaviors In Organic Liquid and Vapor Mediamentioning

confidence: 99%

Organic Molecule‐Driven Polymeric Actuators

Lin

Zhang

Xiao

et al. 2019

Macromol. Rapid Commun.

View full text Add to dashboard Cite

Inspired by the motions of plant tissues in response to external stimuli, significant attention has been devoted to the development of actuating polymeric materials. In particular, polymeric actuators driven by organic molecules have been designed due to their combined superiorities of tunable functional monomers, designable chemical structures, and variable structural anisotropy. Here, the recent progress is summarized in terms of material synthesis, structure design, polymer–solvent interaction, and actuating performance. In addition, various possibilities for practical applications, including the ability to sense chemical vapors and solvent isomers, and future directions to satisfy the requirement of sensing and smart systems are also highlighted.

show abstract

Solvent triggered irreversible shape morphism of biopolymer films

Cited by 27 publications

References 34 publications

Penetrant-Induced Glass-like Transition in Thin Chitosan Films

Penetrant-Induced Glass-like Transition in Thin Chitosan Films

Bidirectional Actuation of Silk Fibroin Films: Role of Water and Alcohol Vapors

Organic Molecule‐Driven Polymeric Actuators

Contact Info

Product

Resources

About