| 2012th Bachelor |
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Title: The Preparation and Characterization of PAMAM SAMs Writer: Zheng Wang Supervisor: Wei Wu, Yong Zhong Abstract:In this study, we hydroxylated the surface of the silicon to make it active. Subsequently, self-assembled monolayers on hydroxyl-terminated silicon wafers were prepared by deposition and coating method. We verified the self-assembled monolayers can be formed by hydrogen bond. We also compared the impact of different the self-assembly method on the shape of the membrane and in the same method, the impact of different conditions on film morphology. The effect of the pretreatment and self-assembled was observed by goniometical measurements. The structure and morphology of layers were characterized by atomic force microscope (AFM).We find that self-assembled PAMAM monolayer were prepared successfully. Monolayers obtained by coating were denser than monolayers obtained by deposition.
Title: The Preparation and Biocompatibility Studies of Natural Seaweed Fiber/ Unsaturated Resin Composite Material Writer: Linlin Hui Supervisor: Wei Wu, Jiawei Wang Abstract:This study takes the natural seaweed fiber as reinforcing material, selecting two representative thermosetting resin, unsaturated polyester resin and epoxy resin as base material, to study the preparation and properties of natural seaweed fiber reinforced thermosetting resin composite material. The further research has done to study the influence of composite material interface compatibility with different pretreatment methods for natural seaweed fiber. Natural seaweed fiber in the TGA appears multi-stage thermal degradation phenomena. Compared with other natural plant fiber, the process of thermal degradation of the natural seaweed fiber itself has high heat resistance. Using the scanning electron microscopy (SEM) to observe the impact section of composites. In summary, natural seaweed fiber with the appropriate surface treatment can be used to improve the fiber dispersion and compatibility issues in thermosetting materials, and to a certain extent to improve the damping properties of epoxy resin.
Title: Preparation on PEN/TPEE and Mechanism of PEN Modified by TPEE Writer: Kai Lei Supervisor: Wei Wu, Liying Bi Abstract:In this paper，the characteristics and development prospects of polyethylene naphthalate glycol （PEN） and thermoplastic polyester elastomer （TPEE） are briefly described，so as the synthesis method of the PEN．Describes an existing PEN blending modification of some results and conclusions，and further discussion on this．By TPEE toughened modification of the PEN，it is hoping that not to lower the PEN under the premise of excellent mechanical properties，but improve their impact，and get excellent blend of materials，laying the foundation for expanding the application of PEN，and the study of TPEE PEN of blended mechanism．There are five components of PEN/TPEE blends，namely 100/0，95/5，90/10，85/15 and 80/20．The blends are blending by extrusion system and test samples are taken by injection system．Material mechanical properties，thermal properties，crystallization and the structure of impact section of PET/TPEE blend were studied by mechanical tests，thermal analysis （TGA，DSC） and SEM，and the internal structure of entire blends is further explored by infrared spectroscopy．
Title: Preparation and Mechanical Properties of Natural Seaweed Fiber/ Unsaturated Resin Composite Material Writer: Kai Xu Supervisor: Wei Wu, Jiawei Wang Abstract:Seaweed fiber (SW)/the epoxy resin composites were prepared with various contents of seaweed fiber (SW) as the reinforcing material and epoxy resin as the matrix. To improve the mechanical properties and thermal properties of the composites, we selected the diethylenetriamine as the curing agent and treated the seaweed fiber by NaOH and NaCLO. Besides, flexural, tensile and impact tests were performed to observe mechanical behavior of the specimens. The composites had better mechanical properties than the other composites with the same content of seaweed fibers or epoxy resin. With the increasing content of the seaweed fiber in the composite system after the study, tensile strength, flexural strength and Rockwell hardness are improved. In summary, we can produce green composites, which will have important applications in certain areas, through the appropriate surface treatment and the molding process. |
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