Several material properties of soft matter research

Title: Several material properties of soft matter research
Author: Fan Chunzhen
Degree-granting units: Fudan University
Keywords: Soft matter;; complex fluids;; nonlinear optical response;; colloidal crystals;; ferrofluid;; FGM
Abstract:
Soft Matter is a new area of ​​research in recent years. It is in the ideal solid and liquid state of matter between a complex, usually formed by the molecules and groups, Magnetic lifter with the complexity and flexibility are two main features. It's a significant feature of the weak force causes strong changes. Soft matter in nature, life, body, daily life and widespread production, such as liquid crystal, polymer, gel, film, foam, particulate matter, protein and so on. Changes in soft matter systems mainly by the entropy (heat fluctuation) caused, that is entropy dominated. Soft material and our daily lives closely linked, such as rubber, detergent, milk, cosmetics, etc.; organism is basically composed of a soft material, such as cells, proteins, DNA and so on. Many strange behavior of soft material, rich content and extensive application of the physical background of more and more aroused the interest of researchers. Also, soft matter physics has become a new frontier, is challenging and important research direction.
The main work of this study several theoretical properties of soft materials. Including colloidal crystals in the nonlinear optical response, based ferrofluid and magnetic second harmonic of the magnetic photonic crystals, colloidal particles in non-uniform oscillating dipole moment under the DEP force and the gradient effect of the thermal material shape and electrical properties.
This paper is structured as follows:
The first chapter, background information, describes the characteristics and soft matter research. In particular, we focus on colloidal crystals, these two types of soft ferromagnetic material flow system, and our theoretical calculations related to the gradient material. The second chapter in this work, based on Ewald-Kornfeld equation, we study colloidal crystals in the third-order nonlinear optical response (third harmonic and non-degenerate four-wave mixing). Which colloidal crystals is the gradient of the nano-scale dielectric particles suspended in the liquid matrix to form an orderly lattice structure. Theoretical calculations show that by adjusting the local electric field or the lattice parameter, the effective nonlinear optical response system can be greatly enhanced, and the resonance frequency of http://www.999magnet.com/ occurrence of a smaller red shift immediately move. The same way, we consider a colloidal crystal the second harmonic response. The results show that an effective system of nonlinear optical response can be adjusted by local electric field and lattice parameters is enhanced. Finally, we discuss how to optimize the Ewald-Kornfeld summation formula.
Chapter III, we studied the optical response based on characteristics of magnetic fluid. First introduced to achieve the magnetic ferrofluid-based second harmonic of the nonlinear optical response. Then the whole system is non-magnetic nano-thin layer of coated ferromagnetic nanoparticles suspended in a single-axis matrix liquid form, which is a nano-thin layer of second-order nonlinear susceptibility within the Ping-optical material. Under the influence of an external magnetic field, ferromagnetic nanoparticles occur superparamagnetic response, arranged in chain-like structure. Then through the introduction of the magnetic field to study the localization factors increase the system's external magnetic field response. Theoretical calculations show that, under the influence of external magnetic field, the entire system of nonlinear optical response is enhanced, and the resonance peak red-shifted. Next, we consider the magnetic ferrofluid-based photonic crystals. By the ferromagnetic fluid and the formation of dielectric material alternating one-dimensional photonic crystal structure, due to the magnetic field caused by the anisotropy of ferromagnetic nanoparticles structure, making a photonic band gap control of the magnetic field.
Chapter IV, the use of first principles, we calculated the non-uniform oscillating dipole moment in colloidal particles under the DEP force. DEP refers to the colloidal particles in the external non-uniform electric field is moved to this phenomenon. Which colloidal particles are continuously changing gradient material that is dielectric constant or conductivity is a function of position. The results show that the applied electric field under the influence of non-uniform, multi-dipole interaction between the particles and the particles within the space fluctuations of the DEP force has a great effect.
Chapter V, based on coordinate transformation, we first study the anisotropy associated with the shape of the heat conduction in graded materials. The results show that for the prolate ellipsoid shape of the gradient material, can achieve equivalent 'negative' thermal conductivity. Further analysis can be found, equivalent to 'negative' thermal conductivity is due to the specific shape of the gradient thermal conductivity of the material caused by the oscillation, and any point in the region along different directions to meet the sum of the thermal conductivity of the sum theorem. This material is equivalent to 'negative' thermal conductivity can be applied to thermal rectification. Similarly, we studied the electric displacement vector associated with the shape anisotropy of the characteristics of graded materials, simulation results show that the shape of the gradient for a particular material can be induced an equivalent electric polarization reversal. And the equivalent electric polarization reversal is reversed by the gradient materials within the region in the dielectric constant oscillation caused, for one thing, the dielectric constant along the sum of all directions to meet the sum theorem. For the spherical cloak polarization reversal does not occur, but for ellipsoidal shape cloak, when the ellipsoid's long axis and short axis ratio greater than 1, the equivalent polarization reversal began to appear, and when a: b = 5:2 polarization reversal when the most obvious. With a: b increases and is close to infinity, the polarization reversal gradually disappear. We also consider different forms of shielding cloak of efficiency, for there is no dissipation and the efficiency of the shielding cloak of dissipation are compared.