AI Article Synopsis
- - The Young's modulus of multilayer films made from nanofibrillated cellulose (NFC) and polyethyleneimine (PEI) was measured using a technique called SIEBIMM, revealing a significant difference in stiffness depending on environmental conditions.
- - At 50% humidity, the films exhibited a Young's modulus of 1.5 GPa, while in a vacuum, this value increased dramatically to 17.2 GPa, highlighting the impact of moisture on material properties.
- - PEI serves to bond the NFC layers together but hinders optimal hydrogen bonding, leading to reduced elastic modulus in humid conditions compared to pure NFC films, with structural changes observed at higher strains.
Article Abstract
The Young's modulus of multilayer films containing nanofibrillated cellulose (NFC) and polyethyleneimine (PEI) was determined using the strain-induced elastic buckling instability for mechanical measurements (SIEBIMM) technique. (1) Multilayer films were built up on polydimethylsiloxane substrates using electrostatic layer-by-layer assembly. At 50% relative humidity, SIEBIMM gave a constant Young's modulus of 1.5 ± 0.2 GPa for 35-75 nm thick films. Conversely, in vacuum, the Young's modulus was 10 times larger, at 17.2 ± 1.2 GPa. A slight decrease in buckling wavelength with increasing strain was observed by scanning electron microscopy with in situ compression, and above 10% strain, extensive cracking parallel to the compressive direction occurred. We conclude that whereas PEI acts as a "glue" to hold multiple layers of NFC together, it prevents full development of hydrogen bonding and specific fibril-fibril interactions, and at high humidity, its hygroscopic nature decreases the elastic modulus when compared with pure NFC films.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1021/bm101330w | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
A Force-Sensor-Less Approach for Rapid Young's Modulus Identification of Heterogeneous Soft Tissue.
J Biomech Eng
January 2025
State Key Laboratory of Fluid Power and Mechatronic Systems, Department of Mechanical Engineering, Zhejiang University, Hangzhou, 315000, China.
Due to individual differences, accurate identification of tissue elastic parameters is essential for biomechanical modeling in surgical guidance for hepatic venous injections. This paper aims to acquire the absolute Young's modulus of heterogeneous soft tissues during endoscopic surgery with 2D ultrasound images. First, we introduced a force-sensor-less approach that utilizes a pre-calibrated soft patch with a known Young's modulus and its ultrasound images to calculate the external forces exerted by the probe on the tissue.
View Article and Find Full Text PDFMachine Learning Interatomic Potential for Modeling the Mechanical and Thermal Properties of Naphthyl-Based Nanotubes.
J Chem Theory Comput
January 2025
Physics Postgraduate Program, Institute of Physics, University of Brasília, 70910-900 Brasília-DF, Brazil.
Two-dimensional (2D) nanomaterials are at the forefront of potential technological advancements. Carbon-based materials have been extensively studied since synthesizing graphene, which revealed properties of great interest for novel applications across diverse scientific and technological domains. New carbon allotropes continue to be explored theoretically, with several successful synthesis processes for carbon-based materials recently achieved.
View Article and Find Full Text PDFSexual Dimorphism in the Downregulation of Extracellular Matrix Genes Contribute to Aortic Structural Stiffness in Female Mice.
Am J Physiol Heart Circ Physiol
January 2025
Vascular Biology Center and Department of Medicine, Medical College of Georgia at Augusta University, Augusta, GA USA.
The contribution of sex hormones to cardiovascular disease, including arterial stiffness, is established; however, the role of sex chromosome interaction with sex hormones, particularly in women, is lagging. Arterial structural stiffness depends on the intrinsic properties and transmural wall geometry that comprise a network of cells and extracellular matrix (ECM) proteins expressed in a sex-dependent manner. In this study, we used four-core genotype (FCG) mice to determine the relative contribution of sex hormones versus sex chromosomes or their interaction with arterial structural stiffness.
View Article and Find Full Text PDFExploration of the dynamics of otic capsule and intracochlear pressure: Numerical insights with experimental validation.
J Acoust Soc Am
January 2025
Department of Otorhinolaryngology, Head and Neck Surgery, University Hospital Zurich, University of Zurich, Zurich, Switzerland.
The otic capsule and surrounding temporal bone exhibit complex 3D motion influenced by frequency and location of the bone conduction stimulus. The resultant correlation with the intracochlear pressure is not sufficiently understood, thus is the focus of this study, both experimentally and numerically. Experiments were conducted on six temporal bones from three cadaver heads, with BC hearing aid stimulation applied at the mastoid and classical BAHA locations across 0.
View Article and Find Full Text PDFMicrofluidic-assisted sol-gel preparation of monodisperse mesoporous silica microspheres with controlled size, surface morphology, porosity and stiffness.
Nanoscale
January 2025
National Engineering Research Center for Colloidal Materials, School of Chemistry & Chemical Engineering, Shandong University, Jinan 250100, P. R. China.
The controllable synthesis of monodisperse mesoporous silica microspheres with unique physicochemical properties is becoming increasingly important for a variety of applications such as catalysts, chromatography, drug delivery and sensors. Here, we report a facile microfluidic-assisted sol-gel method for the preparation of silica microspheres with precisely controlled properties such as the size of the microspheres, the surface morphology, porosity and stiffness. All these properties can be manipulated by changing specific synthesis parameters, such as changing the microfluidic channels to tune the size of the microdroplets (tens to hundreds of microns), changing the contents of the precursor solution to manipulate the surface morphology (wrinkled to smooth surface) and changing the gelation/annealing conditions to tune the porosity (surface area up to 1021 m g) and stiffness of the microspheres (elastic modulus tunable from 0.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!