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:

An ion-induced low-oil-adhesion organic/inorganic hybrid film for stable superoleophobicity in seawater. Superoleophobicity under seawater: An ion-induced low-oil-adhesion film with underwater superoleophobicity is prepared by a typical layer-by-layer (LBL) method. Under an artificial marine environment with high ion-strength, the prepared polyelectrolytes/AuNPs hybrid film becomes rougher and possesses a higher water ratio, which in turn endows the film with superoleophobicity and low underwater oil adhesion. The as-prepared film shows excellent environmental stability in artificial seawater. This study provides a new strategy for controlling the self-cleaning property and accelerating the development of stable underwater superoleophobic films.
{"Chemical": []}