Hiện
tại, vật liệu cao su nanocomposite – dùng chất độn kích thước nano – thu hút sự
quan tâm rộng rãi do tính chất cơ lý tốt. Các chất độn thường được sử dụng
trong vật liệu cao su nanocomposite là đất sét, than đen. Phần tài liệu sau đây
sẽ giới thiệu chung về chất độn carbon nanotubes.
…
Over
recent years, carbon nanotubes (CNT) have inspired scientists for a range of
potential applications [7–12]. Carbon nanotubes are allotropes of carbon with a
unique atomic structure consisting in covalently bonded carbon atoms arranged
in long cylinders with typical diameters in the range 1–50 nm and a wide
variety of lengths. Individual carbon nanotubes are characterized by a high
aspect ratio (300–1000), high flexibility [13] and unique combination of
mechanical, electrical and thermal properties [14, 15]. The combination of
these properties with a very low mass density [16] makes them potentially useful
as ideal reinforcing fibers for high-performance polymer composites.
Carbon
nanotubes are usually produced by three techniques: arc discharge, laser
ablation and chemical vapor deposition. The quality and yield of carbon
nanotubes strongly depend on the synthesis and purification techniques and the
specific growth conditions used [11]. There are two basic types of CNT:
single-walled carbon nanotubes (SWCNT) and multiwalled carbon nanotubes
(MWCNT). The structure of a SWCNT is characterized by wrapping a one-atom thick
layer of graphite called graphene (graphene is a monolayer of sp2-bonded
carbon atoms) into a seamless cylinder. The carbon atoms in the cylinder have
partial sp3 character that increases as the radius of curvature of
the cylinder decreases. SWCNT exhibit important electric properties that are
not shared by the multiwalled carbon nanotubes.
MWCNT
consist of multiple layers of graphite arranged in concentric cylinders with an
interlayer distance close to the distance between graphene layers in graphite
(circa 0.34 nm). Of particular interest are the double-walled carbon nanotubes
(DWNT) because they combine a similar morphology and properties in relation to SWCNT,
while improving significantly their resistance to chemicals.
…
Trích
đăng từ sách Rubber Nanocomposites:
Preparation, Properties and Applications,
Sabu Thomas và Ranimol Stephen, Wiley, 2010, trang 147 – 148
Nguồn:
www.books.google.com.vn
(vtp-vlab-caosuviet)
