Papers by Keyword: Functional Material

Abstract: The functional magnetite nanoparticles are one of the most important functional materials for nucleic acid separation. Cell lysis and magnetic separation are two essential steps involve in optimizing nucleic acid extraction using the magnetic beads method. Many coating materials, coupling agents, chemical cell lysis, and several methods have been proposed to produce the specific desired properties for nucleic acid extraction. The important properties, such as biocompatibility, stability, linking ability, hydrophobicity, and biodegradable, were considered. The appropriate coating material of magnetite core and coupling agent are necessary to give biomolecules a possibility to link with each other through chemical conjugation. In this review, progress in functional magnetite nanoparticles to optimize the high binding performance in nucleic acid extraction is discussed.

Abstract: Cellulose originating from cotton was used as raw material to prepare the functional supported ionic liquid, which had the advantages including wide source, inexpensiveness and easy modification. After the scientific and efficient synthesis process, the product of cellulose balls was characterized for their moisture content, wet density, framework density, porosity and acid/alkali resistance. Finally, ionic liquid was successfully immobilized on them through chemical bonds, which is expected to be applied as a new material in chemical, biological and environmental fields.

Abstract: Piezoelectric materials, which can couple electrical and mechanical displacements, are one of the most important functional materials nowadays. They comprises piezoelectric monocrystals, piezoelectric polycrystals (piezoelectric ceramics), piezoelectric polymers, and piezoelectric composites. Sensors made of these materials can convert pressure, acceleration, flow rate, etc. to surface charge (voltage) that can be easily processed, and at the same time generate their own energy instead of consuming it. Compared to other electromechanical transduction technologies, piezoelectric sensors have the advantages of high environmental and chemical stability, broad temperature and frequency band, as well as self-sufficiency. Piezoelectric materials can also be used in various applications such as energy harvesters, actuators, transducers, and capacitors. This paper reviews the piezoelectric materials and their recent application progress on sensors and others. These published results show the developing trend of piezoelectric sensors to become lead-free, flexible, and with high performance.

Abstract: The elastocaloric effect (ECE) in latex rubber is experimentally investigated under periodic exposure to tensile force. ECE is measured as a function of elongation and frequency of cycles up to 4 Hz. It was found three ranges of the cycle frequencies in which the different thermodynamic processes were demonstrated: elastocaloric cooling, self-heating and decrease of ECE. The maximal measured value of ECE in latex rubber reached 14 K at relative deformation of the sample equal to 700% at frequencies from 0.1 Hz to 0.3 Hz. Also, the possibility of the practical use of latex rubber for elastocaloric based cooling is discussed.

Abstract: Strong gravitational field induces sedimentation of atoms due to the different body forces acting on respective atoms, and gives a tool for controlling elemental compositions in condensed matter. Vanadium oxide (V-O system) has large contrast in phases like VO, V₂O₃, VO₂, V₂O₅ etc., and shows the respective interesting diverse electrical and optical properties. We performed a strong-gravity experiment (0.39710⁶G at 400°C for 24 hours) on a V₂O₅ polycrystal using the high temperature ultracentrifuge to examine the composition change and further the structure change. It was found by the XRD and Raman scattering method that VO₂ and V₂O₃ phases appeared and the amounts were increased, while one of the V₂O₅ phase decreased gradually along with the increasing gravitational field.

Abstract: Skin-care functional material was mainly produced by three aftertreatments, namely carboxylic acid, alkali and sericin. The emphasis of this study lies in the optimization of material fabrication process, which was developed based on Plackett-Burman design to determine the best impact factor for optimum skin-care effect. The experiment was carried out using Design-Expert 8.0.5 statistical tool. The results of optimization showed that moisture character has been improved markedly and the most 3 significant factors were selected from 6 impacts on moisture rate. This research suggested that fabrics with amino acids own the quality of skin-care effect, which moisture rate has been improved. Plackett-Burman design can successfully sift dominant factors, accordingly confirm the feasibility.

Abstract: As a kind of functional material, gelatin gel is widely used in controlled drug release, biological tissue engineering, photographic and food industries. Plenty of studies on the gelatin gel have been carried out by researchers, which include gelation mechanisms, gelation kinetics, analysis on the crosslinked structure and macroscopic performance during the gelation process. Numerical simulation is a new method used in the study of gelatin sol-gel transition process, which can make up for the deficiency of the experimental research. E.g., the dynamic gelation process makes it difficult to measure the structural and performance parameters in time and space scales in experiments. However, these problems have been solved by numerical simulation method in our previous work. The experimental, theoretical and numerical simulation research on sol-gel transition of gelatin is reviewed, and the progress and difficulties in this field are discussed.

Abstract: In this work, two functional azobenzene-containing metal complexes with different substituted groups have been synthesized and their photoisomerization have also been investigated. It has been found that depending on different substituted groups, the formed azobenzene derivatives showed different properties, indicating distinct regulation of molecular skeletons. Spectral data confirmed commonly the characteristic absorption of substituted groups and aromatic segments in molecular structures. Thermal analysis demonstrated that the structural influence of both compounds in different temperature ranges. The difference of thermal stability is mainly attributed to the formation of Schiff base group and different substituent groups in molecular structure. The photoisomerization of these compounds both in solution and in cast film can undergo trans-to-cis isomerization by UV light irradiation, depending on different substituted groups. The present results have demonstrated that the special properties of azobenzene derivatives can be effectively turned by modifying molecular structures of objective compounds with proper substituted groups, which show potential application in sensor and functional material field.

Abstract: Traditional cooling methods for electronic chips cannot fully meet the increasing cooling requirement of chips with high heat flux at present, so finding high-efficiency and low-cost cooling functional materials, and cooling methods with high efficiency has been a hot spot to explore. In this article, using Fluent 6, we construct a grooved channel physical model and analyze cooling effects of ethylene glycol/water ice slurry as a functional material on the chips under conditions that baffle lengths are 60mm, 80mm and 90mm, the mass flow rates are 0.4kg/s, 0.3kg/s and 0.2kg/s, and the ice fractions are 15%, 20%, 25% respectively. The results show that the chip cooling rate is increasing effectively and the temperature uniformity is better as well as the utilization rate of the latent heat is increasing as the length of baffles, the mass flow rate and the ice fraction are increasing, but the pressure loss resulted from the local effects of the inlet and corners cannot be ignored. Considering the cooling effect and the uniformity of temperature field, the length of baffles should be 83%-93% of length of flow path. In practical projects, the temperature difference between inlet and outlet should be reduced and the diameter of pipes should be decreased in order to take full advantage of the huge latent heat of the ice slurry while the ice is completely melted. Therefore, ice slurry as a functional material has a great potential to cool high integrated electronic chips.

Abstract: Functional material specialty English teaching aims at fostering technical personnel with a high level of English proficiency; however, the goal is not achieved due to the boring teaching mode of imparting knowledge. In the paper, task-based language teaching, which is student-centered and characterized by learning by doing and using, is applied to the functional material specialty English to arouse initiatives of students through completing tasks in authentic situations, thus developing their English comprehensive abilities and professional skills. The task is to prepare sepiolite nanofibers by means of the high-speed air current superfine technique using natural sepiolite samples as raw materials and then make a presentation to describe the whole process of the experiment in English in the class. Teachers should monitor the progress of the task to help students complete the task successfully and develop a sense of responsibility to cultivate their practical ability of language using. Through the task, English comprehensive abilities and professional skills of students are improved, and specialty English teaching abilities of teachers is developed.