Carbon fibers (CFs) have a unique combination of properties which allow them to be widely used as reinforcing materials in advanced polymer composites. The mechanical properties of CF-reinforced polymer composites are governed mainly by the quality of interfacial adhesion between the CFs and the polymer matrix. Surface treatments of CFs are generally carried out to introduce chemical functional groups on the fiber surfaces, which provide the ability to control the surface characteristics of CFs. In this study, we review recent experimental studies concerning various surface treatment methods for CFs. In addition, direct examples of the preparation and properties of CF-reinforced thermosetting composites are discussed.

Abstract
 Introduction
 2. Surface Treatments of CFs
  2.1. Wet chemical methods
   2.1.1. Method I
   2.1.2. Method II
  2.2. Dry chemical methods
   2.2.1. Method I
   2.2.2. Method II
  2.3. Electrochemical methods
   2.3.1. Method I
   2.3.2. Method II
  2.4. Plasma methods
   2.4.1. Method I
   2.4.2. Method II
  2.5. Sizing or coating methods
   2.5.1. Method I
   2.5.2. Method II
 3. Sample Preparation Methods
  3.1. Cyanate ester-based composites
   3.1.1. Preparation method I
   3.1.2. Preparation method II
   3.1.3. Preparation method III
  3.2. Epoxy-based composites
   3.2.1. Preparation method I
   3.2.2. Preparation method II
   3.2.3. Preparation method III
   3.2.4. Preparation method IV
  3.3. Phenolic resin-based composites
   3.3.1. Preparation method I
   3.3.2. Preparation method II
  3.4. Polyester-based composites
  3.5. Polyimide-based composites
   3.5.1. Preparation method I
   3.5.2. Preparation method II
   3.5.3. Preparation method III
   3.5.4. Preparation method IV
  3.6. Vinyl ester-based composites
   3.6.1. Preparation method I
   3.6.2. Preparation method II
   3.6.3. Preparation method III
 4. Mechanical and Electrical Properties
  4.1. Cyanate ester-based composites
  4.2. Epoxy-based composites
  4.3. Phenolic resin-based composites
  4.4. Polyester-based composites
  4.5. Polyimide-based composites
  4.6. Vinyl ester-based composites
 5. Summary
 Acknowledgements
 References

• Fan-Long Jin(Department of Polymer Materials, Jilin Institute of Chemical Technology, Jilin City 132022, People’s Republic of China) Corresponding author
• Soo-Jin Park(Department of Chemistry, Inha University, Incheon 402-751, Korea) Corresponding author