Browse
Submit Data
Databases
API
Help

Dataset Information

12 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Solvent-Free Ultrasonic Dispersion of Nanofillers in Epoxy Matrix.

ABSTRACT: Dispersion of carbon nanotubes and carbon nanofibers is a crucial processing step in the production of polymer-based nanocomposites and poses a great challenge due to the tendency of nanofillers to agglomerate. One of the most effective methods for dispersion is the use of a three-roll mill, which is a well-established method and results in agglomerates below 5 µm. Nevertheless, this process is time-consuming and thus a limiting factor for industrial applications. Our aim was to establish an easy and efficient ultrasonic dispersion process, characterize the dispersion parameters, and compare both methods, ultrasonication and the three-roll mill. We applied rheological tests and analyzed the agglomerate sizes by an image fit of the microscopy images. All these analyses combined deliver a valuable set of information about the dispersion's quality and, therefore, allows the improvement and further adaptation of the dispersion process.

SUBMITTER: Zanghellini B

PROVIDER: S-EPMC7835899 | biostudies-literature | 2021 Jan

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

Solvent-Free Ultrasonic Dispersion of Nanofillers in Epoxy Matrix.

Zanghellini Benjamin B Knaack Patrick P Schörpf Sebastian S Semlitsch Karl-Heinz KH Lichtenegger Helga C HC Praher Bernhard B Omastova Maria M Rennhofer Harald H

Polymers 20210119 2

Dispersion of carbon nanotubes and carbon nanofibers is a crucial processing step in the production of polymer-based nanocomposites and poses a great challenge due to the tendency of nanofillers to agglomerate. One of the most effective methods for dispersion is the use of a three-roll mill, which is a well-established method and results in agglomerates below 5 µm. Nevertheless, this process is time-consuming and thus a limiting factor for industrial applications. Our aim was to establish an eas ...[more]

PMID: 33478153

Similar Datasets

Calorimetric and Dielectric Investigations of Epoxy-Based Nanocomposites with Halloysite Nanotubes as Nanofillers.

Project description:Epoxy nanocomposites are promising materials for industrial applications (i.e., aerospace, marine and automotive industry) due to their extraordinary mechanical and thermal properties. Here, the effect of hollow halloysite nanotubes (HNT) on an epoxy matrix (Ep) was the focus of the study. The structure and molecular mobility of the nanocomposites were investigated using a combination of X-ray scattering, calorimetry (differential (DSC) and fast scanning calorimetry (FSC)) and dielectric spectroscopy. Additionally, the effect of surface modification of HNT (polydopamine (PDA) and Fe(OH)3 nanodots) was considered. For Ep/HNT, the glass transition temperature (Tg) was decreased due to a nanoparticle-related decrease of the crosslinking density. For the modified system, Ep/m-HNT, the surface modification resulted in enhanced filler-matrix interactions leading to higher Tg values than the pure epoxy in some cases. For Ep/m-HNT, the amount of interface formed between the nanoparticles and the matrix ranged from 5% to 15%. Through BDS measurements, localized fluctuations were detected as a β- and γ-relaxation, related to rotational fluctuations of phenyl rings and local reorientations of unreacted components. A combination of calorimetry and dielectric spectroscopy revealed a dynamic and structural heterogeneity of the matrix, as confirmed by two glassy dynamics in both systems, related to regions with different crosslinking densities.

| S-EPMC8157573 | biostudies-literature

Ultra-high dispersion of graphene in polymer composite via solvent free fabrication and functionalization.

Project description:The drying process of graphene-polymer composites fabricated by solution-processing for excellent dispersion is time consuming and suffers from a restacking problem. Here, we have developed an innovative method to fabricate polymer composites with well dispersed graphene particles in the matrix resin by using solvent free powder mixing and in-situ polymerization of a low viscosity oligomer resin. We also prepared composites filled with up to 20 wt% of graphene particles by the solvent free process while maintaining a high degree of dispersion. The electrical conductivity of the composite, one of the most significant properties affected by the dispersion, was consistent with the theoretically obtained effective electrical conductivity based on the mean field micromechanical analysis with the Mori-Tanaka model assuming ideal dispersion. It can be confirmed by looking at the statistical results of the filler-to-filler distance obtained from the digital processing of the fracture surface images that the various oxygenated functional groups of graphene oxide can help improve the dispersion of the filler and that the introduction of large phenyl groups to the graphene basal plane has a positive effect on the dispersion.

| S-EPMC4360639 | biostudies-literature

Solvent-Free Fabrication of an Elastomeric Epoxy Resin Using Glycol Lignin from Japanese Cedar.

Project description:In this study, a simple formulation of softwood-derived glycol lignin (GL)-based epoxy resin with a high GL content of greater than 50 wt % was demonstrated by direct mixing with poly(ethylene glycol) diglycidyl ether (PEGDGE), an aliphatic epoxide, without using any solvent. Because the GL powder produced from poly(ethylene glycol) (PEG400) solvolysis of Japanese cedar softwood meal was a PEG400-modified lignin (GL400), a strong affinity between PEG counterparts facilitates the uniform mixing of GL400 with PEGDGE, and one component uncured GL400/PEGDGE epoxy resin was prepared at a relatively lower temperature (100 °C) than the curing temperature (130 °C). The epoxy curing reaction was monitored by 1H NMR and Fourier transform infrared spectroscopies. The physical and mechanical properties of the epoxy resins with different GL400 contents were then evaluated. The developed resins exhibited good flexibility and elasticity depending on the GL400 content.

| S-EPMC6811843 | biostudies-other

Enhanced Mechanical Properties of Multiscale Carbon Fiber/Epoxy Unidirectional Composites with Different Dimensional Carbon Nanofillers.

Project description:Ammonia modified graphene-carbon nanotubes/continuous carbon fiber reinforced epoxy unidirectional multiscale composites (AMGNS-MWCNT/CFEP) were prepared by adding ammonia modified graphene and carbon nanotubes to an epoxy matrix to reduce agglomeration of carbon nanofillers in the epoxy matrix and improve composites properties. Fourier transform infrared spectroscopy (FTIR), scanning electron microscope (SEM), and universal testing machines were used to characterize the properties of carbon nanofillers, AMGNS-MWCNT/epoxy nanocomposites, and AMGNS-MWCNT/CFEP unidirectional composites. When the AMGNS-MWCNT content was 1.0 wt%, flexural strength, the flexural modulus and interlaminar shear strength of AMGNS-MWCNT/CFEP unidirectional composites reached the maximum value of 1520.3 MPa, 138.88 GPa, and 87.80 MPa, respectively, which were 12.5%, 9.42%, and 10.1% higher than that of carbon fiber reinforced epoxy unidirectional composites (CFEP). The synergistic mechanism of two carbon nanofillers in the matrix is discussed.

| S-EPMC7558300 | biostudies-literature

Boehmite Nanofillers in Epoxy Oligosiloxane Resins: Influencing the Curing Process by Complex Physical and Chemical Interactions.

Project description:In this work, a novel boehmite (BA)-embedded organic/inorganic nanocomposite coating based on cycloaliphatic epoxy oligosiloxane (CEOS) resin was fabricated applying UV-induced cationic polymerization. The main changes of the material behavior caused by the nanofiller were investigated with regard to its photocuring kinetics, thermal stability, and glass transition. The role of the particle surface was of particular interest, thus, unmodified nanoparticles (HP14) and particles modified with p-toluenesulfonic acid (OS1) were incorporated into a CEOS matrix in the concentration range of 1-10 wt.%. Resulting nanocomposites exhibited improved thermal properties, with the glass transition temperature (Tg) being shifted from 30 °C for unfilled CEOS to 54 °C (2 wt.% HP14) and 73 °C (2 wt.% OS1) for filled CEOS. Additionally, TGA analysis showed increased thermal stability of samples filled with nanoparticles. An attractive interaction between boehmite and CEOS matrix influenced the curing. Real-time infrared spectroscopy (RT-IR) experiments demonstrated that the epoxide conversion rate of nanocomposites was slightly increased compared to neat resin. The beneficial role of the BA can be explained by the participation of hydroxyl groups at the particle surface in photopolymerization processes and by the complementary contribution of p-toluenesulfonic acid surface modifier and water molecules introduced into the system with nanoparticles.

| S-EPMC6540208 | biostudies-literature

Evidence-based guidelines for the ultrasonic dispersion of cellulose nanocrystals.

Project description:Nanoparticles possess unique, size-driven properties. However, they can be challenging to use as they easily agglomerate - their high surface area-to-volume ratio induces strong interparticle forces, generating agglomerates that are difficult to break. This issue prevails in organic particles as well, such as cellulose nanocrystals (CNCs); when in their dried form, strong hydrogen bonding enhances agglomeration. Ultrasonication is widely applied to prepare CNC suspensions, but the methodology employed is non-standardized and typically under-reported, and process efficiency is unknown. This limits the ability to adapt dispersion protocols at industrial scales. Herein, numerical simulations are used in conjunction with validation experiments to define and optimize key parameters for ultrasonic dispersion of CNCs, allowing an operating window to be inferred.

| S-EPMC7786632 | biostudies-literature

Impact of ultrasonic dispersion on the photocatalytic activity of titania aggregates.

Project description:The effectiveness of photocatalytic materials increases with the specific surface area, thus nanoscale photocatalyst particles are preferred. However, such nanomaterials are frequently found in an aggregated state, which may reduce the photocatalytic activity due to internal obscuration and the extended diffusion path of the molecules to be treated. This paper investigates the effect of aggregate size on the photocatalytic activity of pyrogenic titania (Aeroxide(®) P25, Evonik), which is widely used in fundamental photocatalysis research. Well-defined and reproducible aggregate sizes were achieved by ultrasonic dispersion. The photocatalytic activity was examined by the color removal of methylene blue (MB) with a laboratory-scale setup based on a plug flow reactor (PFR) and planar UV illumination. The process parameters such as flow regime, optical path length and UV intensity are well-defined and can be varied. Our results firstly show that a complete dispersion of the P25 aggregates is not practical. Secondly, the photocatalytic activity is not further increased beyond a certain degree of dispersion, which probably corresponds to a critical size for which UV irradiation can penetrate the aggregate without significant obscuration.

| S-EPMC4685913 | biostudies-literature

Implicit treatment of solvent dispersion forces in protein simulations.

Project description:A model is proposed for the evaluation of dispersive forces in a continuum solvent representation for use in large-scale computer simulations. The model captures the short- and long-range effects of water-exclusion in conditions of partial and anisotropic hydration. The model introduces three parameters, one of which represents the degree of hydration (water occupancy) at any point in the system, which depends on the solute conformation, and two that represent the strength of water-water and water-solute dispersive interactions. The model is optimized for proteins, using hydration data of a suboptimally hydrated binding site and results from dynamics simulations in explicit water. The model is applied to a series of aliphatic-alcohol/protein complexes and a set of binary and ternary complexes of various sizes. Implications for weak and ultra-weak protein-protein association and for simulation in crowded media are discussed.

| S-EPMC4640197 | biostudies-literature

Solvent-tuned ultrasonic synthesis of 2D coordination polymer nanostructures and flakes.

Project description:Herein, a new 2-dimensional coordination polymer based on copper (II), {Cu2(L)(DMF)2}n, where L stands for 1,2,4,5-benzenetetracarboxylate (complex 1) is synthesized. Interestingly, we demonstrate that both solvent and sonication are relevant in the top-down fabrication of nanostructures. Water molecules are intercalated in suspended crystals of complex 1 modifying not only the coordination sphere of Cu(II) ions but also the final chemical formula and crystalline structure obtaining {[Cu(L)(H2O)3]·H2O}n (complex 2). On the other hand, ultrasound is required to induce the nanostructuration. Remarkably, different morphologies are obtained using different solvents and interconversion from one morphology to another seems to occur upon solvent exchange. Both complexes 1 and 2, as well as the corresponding nanostructures, have been fully characterized by different means such as infrared spectroscopy, x-ray diffraction and microscopy.

| S-EPMC7803821 | biostudies-literature

Production of Nanocellulose Using Hydrated Deep Eutectic Solvent Combined with Ultrasonic Treatment.

Project description:Pretreatment approaches are highly desirable to improve the commercial viability of nanocellulose production. In this study, we propose a new approach to mass produce nanocellulose using a hydrated choline chloride/oxalic acid dihydrate deep eutectic solvent (DES) combined with an ultrasonic process. The hydrogen bond acidity, polarizability, and solvation effect reflected by the Kamlet-Taft solvatochromic parameters did not decrease even after the addition of large amounts of water. Instead, the water facilitated the ionization of H+ and delocalization of Cl- ions, forming new Cl-H2O ionic hydrogen and oxalate-H2O hydrogen bonds, which are critical for improving the solvent characteristics. One pass of kraft pulp through the hydrated DESs (80 °C, 1 h) was sufficient to dissociate the kraft pulp into cellulose nanofibers or cellulose nanocrystals using an 800 W ultrasonic treatment. The present study represents an alternative route for the kraft pulp pretreatment and the large-scale production of nanocellulose.

| S-EPMC6648160 | biostudies-literature

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data