UNIVERSITY OF SCIENCEMATERIAL SCIENCE

MAJOR: POLYMER AND COMPOSITE

Lecturer: Mr.Lưu Kiến Quốc

Members of Group:Nguyễn Thị Kim Thủy1319389Võ Thị Thanh Thúy 1319384Huỳnh Ngọc Hương Thảo 1319352Đặng Trang Minh Thư1319390

CARBON NANOTUBEBASED NANOCOMPOSITES

CONTENTS

What is a carbon nanotubes?

Types of carbon nanotubes?

Properties of carbon nanotubes

Synthesis of carbon nanotubes

Applications

WHAT IS A CARBON NANOTUBES (CNTS)?

Carbon nanotubes are:

Allotrope of carbon that is graphite, in which carbon atom sp2 hybridized state.

Nanotubes are cylindrical fullerenes.

Nanotubes have been constructed with length-to-diameter ratio of up to 132000000:1, significantly large for any other material

TYPES OF CARBON NANOTUBES

CNTs

Single-walled Nanotubes (SWNTS);

Multi-walled Nanotubes (MWNTS).

A single-walled nanotubes (SWNT) have A diameter of close to 1 nanometre, with A tube length that can be many millions of times longer.

A one atom thick layer of graphene into seamless cylinder

It requires catalyst for their synthesis

Single walled CNTS (Graphical Representation)

Single-walled Nanotubes (SWNTS):

Multi-walled nanotubes (MWNT) consist of multiple rolled layers of graphite

To describe structure of MWNT there are two models:• Russian doll model• Parchment model

It can be produced without catalyst

Purity of product is high

Multi-walled nanotubes (MWNTs)

Một phần của ống than nano nhiều vỏ (MWNT) chụp bằng kính hiển vi điện tử

PROPERTIES OF CARBON NANOTUBES

Strength

- CNTs are the strongest, flexible and stiffest materials yet discovered in terms of tensile strength and elastic modulus respectively.

- CNTs are lighter 6 times and stronger 100 times than steels.

Hardness:

The hardness (152 gpa) and bulk modulus (462–546) of carbon nanotubes are greater than diamond, which is considered the hardest material. (That of diamond is 150gpa & 420gpa).

Thermal conductivity :

All nanotubes are expected to be very good thermal conductors along the tube.( Measurements show that a SWNT has a room-temperature thermal conductivity more than copper

Electrical properties:

Because of the symmetry and unique electronic structure of graphene, the structure of a nanotube strongly affects its electrical properties.

PROPERTIES OF CARBON NANOTUBES

SYNTHESIS OF CARBON NANOTUBE

Various techniques have been developed to produce nanotubes in sizeable quantities, which includs:

- Arc discharge

- Laser ablation

- Chemical vapor deposition (CVD)

APPLICATIONS

APPLICATIONS

The most important application of nanotubes, based on their mechanical properties, will be as reinforcements in composite materials to increase the fracture toughness of the composites by absorbing energy through their highly flexible elastic behavior during deformation.

We briefly discuss some developments regarding metal-matrix based nanotube composites.

Addition of carbon nanotubes to the alumina results in lightweight composites and the increasing of strength, fracture toughness.( Firgue 1.15 a, b)

However, the real improvements occur when the nanotubes are purified and well dipersed.( Firgue 1.15 c)

ALUMINA-MATRIX COMPOSITES CONTAINING CARBON NANOTUBES

(MWNTS)

(a) Fracture toughness of multiwalled nanotube (MWNT)/alumina nanocomposite compared with that of sintered nanophase alumina. The inset in (a) shows an indent and resulting cracks.

(b) The micro- structure of the nanocomposite show in.

ALUMINA-MATRIX COMPOSITES CONTAINING CARBON NANOTUBES

(MWNTS)

One of the biggest challenges in processing nanotube composites lies in achieving a ‘good’ dispersion.

It is important that the individual nanotubes are distributed uniformly throughout the matrix and well-separated from each other; the presence of agglomerates is extremely undesirable, especially in ceramic matrices, as they can act as defects leading to stress-concentration, and premature failure, particularly if the matrix does not fully penetrate the agglomerate during processing.

ALUMINA-MATRIX COMPOSITES CONTAINING CARBON NANOTUBES

(MWNTS)

ALUMINA-MATRIX COMPOSITES CONTAINING CARBON NANOTUBES

(MWNTS)

(c) Diametral strengths of alumina-matrix nanotube composites hot-pressed in ar at 1300OC and 60 mpa for 1h and containing various amounts of MWNT.

Before, carbon nanofiber composite was famous for materials which are light, strong and weak chemically reactions. When CNTs are found, they are replace CNTs because CNTs shave better mechanical properties .

The present tendencies, movever, in composite is to reinforce in polymer

Ex: PPV-CNTs, conductivity increased 8 times

SUMMARY

Nanocomposite science and technology (p. M. Ajayan, L. S. Schadler, P. V. Braun)

Http://doc.Edu.Vn/tai-lieu/ong-nano-cac-bon-cac-phuong-phap-che-tao-tinh-chat-va-ung-dung-69560/

Http://www.Slideshare.Net/saurabhnandy007/carbon-nanotube-report?Next_slideshow=1

File:///C:/users/ASUS/music/shaffer,%20m%20-%20ceramic%20matrix%20composites%20containing%20carbon%20nanotubes.Pdf

Http://www.Slideshare.Net/SREESANGH/carbon-nanotubes-sreesangh-p-ghosh

Http://www.Slideshare.Net/nkp8490/applications-of-carbon-nanotubes

REFERENCES