Separation Methods of Laser-Induced Carbon Chains in Graphite-Ethanol Suspensions

Irradiation of carbon-containing liquids by ultrashort laser pulses makes it possible to synthesize linear carbon chains (polyynes), which are of great practical interest for optics and electronics. To obtain homogeneous suspensions of polyynes, it is important to study the stability of synthesized structures and search for efficient methods of separating polyynes from laser processing byproducts. In this study polyynes were synthesized using irradiation of graphite suspensions in ethanol by a picosecond laser source (τ = 10 ps, f = 10 kHz, λ = 1064 nm). The processed suspensions contained polyynes of different length (C₈H₂–C₁₆H₂) and some other carbon components. The stability of polyynes was investigated, and a systematic comparison of the results of separating polyynes from other components of irradiated suspensions using filtering, sedimentation, and centrifugation was performed. The optical properties of synthesized polyynes were investigated by optical spectroscopy. The laser processing byproducts were studied using transmission electron microscopy.