Preparation And Performance Of Metal Nanoparticles Functionalized Conductive Composites

Metal nanomaterials have excellent electrical conductivity,thermal conductivity and catalytic properties,and have a wide range of applications in antibacterial,catalytic,sensing,biomedical,electromagnetic interference shielding and other fields.Fiber wires possess stable chemical properties,and are considered as ideal substrate materials for preparing high conductivity and high strength composites.In this thesis,one-dimensional conductive composites have been prepared by coating silver nanoparticles(Ag NPs)or copper nanoparticles(Cu NPs)on human hair(HH),cellulose nanofiber(CNF),textile cotton fiber(CF)and other fibers with different scales by electroless deposition(ELD)method.The applications in the fields of electrochemical enzyme-free glucose detection,electromagnetic interference shielding and strain sensor have also been studied.Detail contents are as follows:(1)Preparation of HH@Cu NPs composites and their properties of enzyme-free glucose sensor.Using silver seeds as the activation site,Cu NPs were uniformly deposited on polydopamine(PDA)modified HH by ELD method.The prepared HH@Cu NPs composites showed excellent electrocatalytic performance for the oxidation of glucose,which exhibited a linear detection to glucose in a wide concentration range of 0.002-5 m M and 5-35 m M with the detection limit of 1.62?M.In practical biological applications,as an enzyme-free glucose electrochemical sensor,it could accurately detect the glucose concentration in human serum samples.(2)Preparation of CNF@Ag NPs composites and their properties of electromagnetic shielding.Ag NPs were uniformly deposited on PDA modified CNF by ELD method,and then the composite films were prepared by vacuum-assisted filtration.Further mechanical pressing treatment was adopted to make the connection between the conductive CNF@Ag NPs fibers more compact,thus improving the conductive performance and electromagnetic shielding efficiency of the flexible CNF@Ag NPs composite films.The electrical conductivity of the composite films obtained by mechanical compression was 1×10⁶ S m^-1,and the electromagnetic shielding efficiency was 93.8 d B.The conductive films had special fiber conductive network structure,which enhanced the reflection ability and absorption efficiency of electromagnetic wave(EMW)in its internal.(3)Fabrication of CF@Cu NPs composites and their properties of strain sensor and electromagnetic shielding.Taking silver seeds as the activation site,Cu NPs were uniformly deposited on PDA modified CF by ELD method.The relationship between the tensile variation length of CF@Cu NPs composites and the output current was studied.The flexible strain sensor had a considerable strain range,and the sensor application of the flexible tension strain sensor was preliminarily obtained.When the conductive CF was stitched into cloth,the electromagnetic shielding efficiency value was 53.2 d B.The internal bundle structure of the CF deposited with Cu NPs formed a good conductive path,and the EMW could be reflected multiple times inside the wire harness,thus increasing the material's ability to reflect and absorb the EMW.