You will be shown an abstract from a biomedical research paper. Given this abstract, your task is to extract all unique entities of the following types: ["Chemical"].

Please return the output as a JSON object of the format: {"Chemical": ["Arsenic", ...]}. The keys should be entity types and values should be lists of extracted entities belonging to the corresponding type. If you cannot find entities belonging to a specific type, the value should be [].

Only output the JSON object and do not include any additional text.

Abstract:

Surfactant-Assisted Assembly of Fullerene (C(60)) Nanorods and Nanotubes Formed at a Liquid-Liquid Interface. Herein we report the surfactant-triggered assembly of fullerene (C(60)) into 3D flowerlike microcrystals at the liquid-liquid interface. C(60) crystals were grown using a liquid-liquid interfacial precipitation (LLIP) method by layering surfactant solution in butanol with a saturated solution of C(60) in benzene. In the LLIP method, it is suggested that the crystal formation mechanism is driven by supersaturation related to the low C(60) solubility in alcohol. We found that the dimensions of the synthesized C(60) flowers depend on the concentration and surfactant type. In the absence of surfactant (i.e., in the butanol/benzene system), 1D C(60) nanowhiskers (nanorods) and C(60) nanotubes (diameter 400 nm-2 μm and length 5-20 μm) are obtained. However, when surfactants are incorporated into the system flowerlike microcrystals consisting of C(60) nanotubes are observed. For instance, crystals grown at the interface of a 0.01% diglycerol monolaurate (C(12)G(2)) nonionic surfactant in butanol with benzene lead to the formation of flower-shaped microcrystals of average sizes in the range of 10-35 μm. To the best of our knowledge, this is the first example of the surfactant-assisted assembly of C(60) crystals. X-ray diffraction (XRD) and transmission electron microscopy (TEM) measurements have shown that fullerene flowers have a hexagonal structure with cell dimensions of a = 2.539 nm and c = 1.021 nm, which differ from that of pristine C(60). Mixtures of flower-shaped C(60) crystals and free-standing C(60) nanotubes are found in the 0.1% C(12)G(2)/butanol system. However, clusters or giant aggregates of nanowhiskers lacking any specific shape are observed in the 1% C(12)G(2)/butanol system although these crystals exhibit hexagonal close-packed structures. Flower-shaped C(60) microcrystals are also observed with anionic surfactants cetyltrimethylammonium bromide (CTAB) and cetyltrimethylammonium chloride (CTAC). C(60) flowers obtained from 0.01% CTAB and 0.01% CTAC also exhibit hexagonal structures with cell dimensions of a = 2.329 nm and c = 1.273 nm, a = 2.459 nm and c = 0.938 nm, respectively. Our C(60) flowers exhibit intense photoluminescence (PL) and a blue-shifted PL intensity maximum compared to the same parameters for pristine C(60), demonstrating the potential to control the optoelectronic properties of fullerene-based nanostructures.
{"Chemical": ["CTAB", "fullerene", "CTAC", "benzene", "Fullerene", "diglycerol monolaurate", "butanol", "C(60)", "cetyltrimethylammonium chloride", "cetyltrimethylammonium bromide", "C(12)G(2)"]}