Preparation And Properties Of Fullerene C₆₀/C₇₀ Crystals And Their Polyaniline Composites

In recent years,with the in-depth research on the doping of fullerene C₆₀/C₇₀materials in p-type conductive polymers,it has been found that the doping of fullerenes C₆₀/C₇₀ can effectively improve the thermal and electrical properties of conductive polymers,and the conductive polymer composite obtained by compounding fullerene C₆₀/C₇₀ and polyaniline by chemical oxidation or in-situ polymerization has attracted attention.Fullerene C₆₀/C₇₀ is mainly combined with PANI in its powder and whisker morphology.Because FW has a series of unique physical and chemical properties,such as electron acceptor properties,optical anisotropy,mechanical properties and solubility in suitable organic solvents,it is important to study the composite materials of FW and conductive polymer PANI.In this paper,we prepared the C₆₀/C₇₀ nanorods in toluene-isopropyl alcohol?IPA?system by liquid-liquid interfacial precipitation?LLIP?method using the relationship between the aggregation state of C₆₀/C₇₀ molecules and the mixing temperature.During the experiment,the aging temperature was 8°C,and the volume ratio of fixed toluene and IPA was 1:3.By changing the mixing temperature of C₆₀/C₇₀-toluene saturated solution and IPA,the C₆₀/C₇₀ nanorods?fullerene nanorob bundles,FNBs?were first prepared at a mixing temperature of 60°C.The constituent structures of C₆₀/C₇₀0 FNBs were characterized by Fourier transform infrared spectroscopy?FT-IR??Raman spectra and X-ray diffraction?XRD?.Optical microscopy?OM?and scanning electron microscopy?SEM?analysis found that C₆₀/C₇₀0 FNBs can be produced only at a mixing temperature of 60°C,with a length of 10-14?m and a diameter of about 3.7?m,uniform distribution,and from a group of nanorods with a diameter of about 130 nm aggregated into a rod bundle.And combined with the results of particle size analysis,the formation mechanism of nanorod bundles was inferred.In this paper,the mother liquors of C₆₀ FW and C₆₀/C₇₀ FNBs were composited by direct ultrasonic mixing method with polyaniline emeraldinebase?PANI-EB?whichwaspreparedbychemical oxidation-N-methyl-2-pyrrolidone?NMP?solution to obtain composites with different morphology.The corrugated C₆₀FW/PANI-EB composites and the wave-like C₆₀/C₇₀FNBs/PANI-EB composites were found by OM and SEM analysis,and the composition of the composites were characterized by FT-IR and ultraviolet-visible spectroscopy?UV-vis?and X-ray photoelectron spectroscopy?XPS?.It was found that C₆₀FW and C₆₀/C₇₀0 FNBs have charge transfer complexes,intermolecular interactions with PANI-EB,respectively.The cyclic voltammetry?CV?,galvanostatic charge-discharge?GCD?and electrochemical impedance spectroscopy?EIS?analysis show that the specific capacitance of C₆₀FW/PANI-EB composite material can reach 813Fg^-1 at a current density of 1 Ag^-1,and the capacitance retention rate is 85.2%(specific capacitance is 693 Fg^-1)after 1500cycles.However,the electrochemical performance of C₆₀/C₇₀0 FNBs/PANI-EB composites is relatively poor.Finally,by comparing the structural and electrical properties of the two composites,it is guessed that there is a big difference in the composite mechanism between the two composites,and the charge transfer complex reaction occurs between C₆₀0 FW and PANI-EB molecules,while C₆₀/C₇₀0 FNBs and PANI-EB only by intermolecular forces,PANI-EB has a low degree of doping,and this point of view is confirmed by FT-IR and UV-vis tests.At the same time,the composite material of PANI-EB on the surface of C₆₀/C₇₀FNBs was changed to obtain the stripe-like composite material,excluding the impact on the formation of charge transfer complexes due to the small amount of PANI-EB complexes.The formation mechanism of the two composites was given.It lays the foundation for the preparation of a composite material of C₆₀/C₇₀ and PANI-EB that is both inexpensive and excellent.