Advanced composites have been broadly applied in civil and military areas. With the emergence of nanomaterials, increasing attention has been given to nano-filled advanced composites. However, the aggregation of nanoparticles in polymer composites during direct dispersion process hinders the achievement of the potential of nano-reinforcement. In order to address this challenge, the spray technique was developed by dispersing a typical nanomaterial, carbon nanofibers (CNFs), onto fabrics to fabricate hybrid CNFs/carbon fiber reinforcements.
The selective reinforcement for composite design is conceptually and theoretically proven. Due to the shortcomings of the manual spray technique, a novel automated spray system was developed to bridge the gap between the present spray technique and the application of selective reinforcement. Subsequently, a statistic experimental investigation was conducted to establish the relation between spray parameters (air pressure, liquid pressure, spray velocity and number of layers) and spray effects. Process maps were then developed to provide a fundamental understanding of this spray system. The sprayed fabric were then characterized and compared using an optical microscope and a scanning electron microscope (SEM).
In this research, the results show that: 1) sprayed CNFs areal density increases with the increase of liquid pressure and the number of spray layers, but decreases with the increase of air pressure and spray velocity; 2) higher air pressure helps the uniform dispersion of CNFs; 3) liquid pressure directly affects the sprayed amount of CNFs, whereas high pressure damages the homogeneous dispersion of CNFs; 4) low spray velocity induces agglomeration although it can increase the deposited amount of CNFs while high velocity favors the dispersion; 5) multilayer spray can not only increase the coated amount of CNFs, but also make the sprayed surface smooth.
|Commitee:||Gang, Daniel Dianchen, Vaughan, Joshua|
|School:||University of Louisiana at Lafayette|
|School Location:||United States -- Louisiana|
|Source:||MAI 54/06M(E), Masters Abstracts International|
|Subjects:||Mechanical engineering, Materials science|
|Keywords:||Carbon nanofibers, Characterization, Composites, Parameteric study, Process map, Spray|
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