▎ 摘　　要

Functionalization of graphene oxide is important for technological applications since it allows integrating into different environments such as biological fluids, polymer matrices, silicon surface and others. Graphene oxide was made through the ultrasonic separation of graphite oxide, and then it was modified with functional group by chloroacetic acid, and finally, the graphene oxide modified with carboxyl groups was prepared. Compared with graphene oxide, the FTIR spectrum of GeneO-COOH showed a weaker -OH peak, a stronger -COOH peak, and a bigger peak width. The results showed that partial epoxy and hydroxyl were activated into carboxyl. Static water contact angle showed that modification of Gene with -COOH was successful, and hydrophilicity of GeneO-COOH increased significantly. On TG curve, the main mass loss of GeneO-COOH showed condensation of COOH groups in the form of a loss of structural water. The curve which reflected the kinetic profiles of recalcification time was changed from steep to gentle along with the increases of the consistency of GeneO-COOH. The recalcification time of GeneO-COOH was prolonged by 11 min at 1.25 mu g/mL, and the value of OD reduced by 8.14%. The hematolysis ratio was less than 5% within a range of 0.5-50 mu g/mL. The anti-clotting property of GeneO-COOH was better than that of Gene at the same low concentration. The improvement was mainly made by carboxyl group with a negative charge. Electrostatic repulsions between carboxyl groups and blood plasma proteins prevented the adhesion of plasma proteins on the surface of GeneO-COOH. Meanwhile, direct complexation between carboxyl group and clotting factor could not be ignored. Then, the recalcification time was significantly delayed. Therefore, modification with carboxyl groups was a method to increase anti-coagulation effective of GeneO.