Field-induced anti-nematic and biaxial ordering in binary mixtures of discotic mesogens and spherical magnetic nanoparticles

Soft Matter ◽  
2020 ◽  
Vol 16 (47) ◽  
pp. 10667-10675
Author(s):  
Stavros D. Peroukidis ◽  
Sabine H. L. Klapp ◽  
Alexandros G. Vanakaras
Keyword(s):  
Magnetic Nanoparticles ◽  
Binary Mixtures ◽  
Computer Simulations ◽  
Liquid Crystalline ◽  
Magnetic Particles ◽  
Equilibrium Structure ◽  
Discotic Mesogens ◽  
External Stimuli

Using computer simulations we explore the equilibrium structure and response to external stimuli of complex magnetic hybrids consisting of magnetic particles in discotic liquid crystalline matrices.

scholarly journals Structure and rheology of soft hybrid systems of magnetic nanoparticles in liquid-crystalline matrices: results from particle-resolved computer simulations

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Nima H. Siboni ◽  
Gaurav P. Shrivastav ◽  
Stavros D. Peroukidis ◽  
Sabine H. L. Klapp
Keyword(s):  
Magnetic Nanoparticles ◽  
Liquid Crystalline ◽  
Magnetic Particles ◽  
Cluster Formation ◽  
Soft Materials ◽  
Equilibrium Dynamics ◽  
Planar Shear ◽  
Highly Nonlinear ◽  
Wide Range ◽  
The Impact

Abstract Hybrid mixtures composed of magnetic nanoparticles (MNP) in liquid crystalline (LC) matrices are a fascinating class of soft materials with intriguing physical properties and a wide range of potential applications, e.g., as stimuli-responsive and adaptive materials. Already in the absence of an external stimulus, these systems can display various types of orientationally disordered and ordered phases, which are enriched by self-assembled structures formed by the MNPs. In the presence of external fields, one typically observes highly nonlinear macroscopic behavior. However, an understanding of the structure and dynamics of such systems on the particle level has, so far, remained elusive. In the present paper we review recent computer simulation studies targeting the structure, equilibrium dynamics and rheology of LC-MNP systems, in which the particle sizes of the two components are comparable. As a numerically tractable model system we consider mixtures of soft spherical or elongated particles with a permanent magnetic dipole moment and ellipsoidal non-magnetic particles interacting via a Gay-Berne potential. We address, first, equilibrium aspects such as structural organization and self-assembly (cluster formation) of the MNPs in dependence of the orientational state of the matrix, the role of the size ratio, the impact of an external magnetic field, and the translational and orientational diffusion of the two components. Second, we discuss the non-equilibrium dynamics of LC-MNP mixtures under planar shear flow, considering both, spherical and non-spherical MNPs. Our results contribute to a detailed understanding of these intriguing hybrid materials, and they may serve as a guide for future experiments.

Chirality-induced phase transitions in some liquid crystalline binary mixtures

1994 ◽  
Vol 17 (4) ◽  
pp. 555-569 ◽  
Author(s):  
Isa Nishiyama ◽  
Atsushi Yoshizawa
Keyword(s):  
Phase Transitions ◽  
Binary Mixtures ◽  
Liquid Crystalline

scholarly journals Design of liquid-crystalline foods via field theoretic computer simulations

2006 ◽  
Vol 17 (5) ◽  
pp. 220-226 ◽  
Author(s):  
Raffaele Mezzenga ◽  
Won Bo Lee ◽  
Glenn H. Fredrickson
Keyword(s):  
Computer Simulations ◽  
Liquid Crystalline

scholarly journals Solvent Dependence of the Rheological Properties in Hydrogel Magnetorheological Plastomer

2020 ◽  
Vol 21 (5) ◽  
pp. 1793 ◽  
Author(s):  
Norhiwani Mohd Hapipi ◽  
Saiful Amri Mazlan ◽  
U. Ubaidillah ◽  
Siti Aishah Abdul Aziz ◽  
Muntaz Hana Ahmad Khairi ◽  
...  
Keyword(s):  
Rheological Properties ◽  
Binary Mixtures ◽  
Binary Solvent ◽  
Iron Particles ◽  
Magnetic Performance ◽  
Solvent Dependence ◽  
Mr Effect ◽  
External Stimuli ◽  
Pva Hydrogel

Chemically crosslinked hydrogel magnetorheological (MR) plastomer (MRP) embedded with carbonyl iron particles (CIPs) exhibits excellent magnetic performance (MR effect) in the presence of external stimuli especially magnetic field. However, oxidation and desiccation in hydrogel MRP due to a large amount of water content as a dispersing phase would limit its usage for long-term applications, especially in industrial engineering. In this study, different solvents such as dimethyl sulfoxide (DMSO) are also used to prepare polyvinyl alcohol (PVA) hydrogel MRP. Thus, to understand the dynamic viscoelastic properties of hydrogel MRP, three different samples with different solvents: water, DMSO, and their binary mixtures (DMSO/water) were prepared and systematically carried out using the oscillatory shear. The outcomes demonstrate that the PVA hydrogel MRP prepared from precursor gel with water shows the highest MR effect of 15,544% among the PVA hydrogel MRPs. However, the samples exhibit less stability and tend to oxidise after a month. Meanwhile, the samples with binary mixtures (DMSO/water) show an acceptable MR effect of 11,024% with good stability and no CIPs oxidation. Otherwise, the sample with DMSO has the lowest MR effect of 7049% and less stable compared to the binary solvent samples. This confirms that the utilisation of DMSO as a new solvent affects the rheological properties and stability of the samples.

Stimulus configuration, long-term potentiation, and the hippocampus

1997 ◽  
Vol 20 (4) ◽  
pp. 629-631 ◽  
Author(s):  
Nestor A. Schmajuk
Keyword(s):  
Neural Network ◽  
Computer Simulations ◽  
Neural Network Model ◽  
Long Term Potentiation ◽  
Stimulus Configuration ◽  
Association Cortex ◽  
Hippocampal Function ◽  
Term Potentiation ◽  
External Stimuli

Shors & Matzel propose that hippocampal LTP increases the effective salience of discrete external stimuli and thereby facilitates the induction of memories at distant places. In line with this suggestion, a neural network model of associative learning and hippocampal function assumes that LTP increases hippocampal error signals to the cortex, thereby facilitating stimulus configuration in association cortex. Computer simulations show that under these assumptions the model correctly describes the effect of LTP induction and blockade in classical discriminations and place learning.

Targeting Magnetic Nanoparticles in High Magnetic Fields for Drug Delivery Purposes

2004 ◽  
Vol 820 ◽  
Author(s):  
Ramazan Asmatulu ◽  
Richard.O. Claus ◽  
Judy S. Riffle ◽  
Michael Zalich
Keyword(s):  
Magnetic Field ◽  
Drug Delivery ◽  
Magnetic Nanoparticles ◽  
Magnetic Fields ◽  
Magnetic Particles ◽  
Guidance System ◽  
Test Results ◽  
Test Parameters ◽  
Magnetic Guidance ◽  
The Magnetic Field

AbstractBiodegradable magnetic nanoparticles were synthesized using Poly(L-Lactic Acid) and magnetite nanoparticles (∼14 nm) at different dosages, and then these nanaoparticles (nanocomposites) and pure magnetic particles were targeted in external magnetic fields by changing the test parameters. The magnetic field test results showed that magnetic saturation, fluid speed, magnetic field distance and particle size were extremely effective for a magnetic guidance system that is needed for an effective drug delivery approach. Thus, it is assumed that such nanoparticles can carry drugs (chemotherapy) to be able to cure cancer tumors as well as many other diseases.

Sign in / Sign up

Export Citation Format

Share Document