A mixing and dispersing apparatus includes a tank body, a stirring part, a dispersing part, and a driving part. The tank body has an accommodating cavity configured to accommodate materials. The stirring part is disposed in the accommodating cavity and configured to mix the materials in the accommodating cavity. The dispersing part is disposed in the accommodating cavity and includes a first cylinder and a second cylinder. The first cylinder has a first cavity in communication with the accommodating cavity, the second cylinder is located in the first cavity, and the second cylinder has a second cavity in communication with the accommodating cavity. The driving part is connected to the stirring part and the dispersing part. The materials mixed in the accommodating cavity flow into the second cavity and flow out after being dispersed in the dispersing part.

A mixing head 3 which mixes a first preparative liquid formulation containing a norbornene-based monomer with a second preparative liquid formulation containing a metathesis polymerization catalyst includes a casing 4, a cap 7, and a mixing rotor 6. A plurality of protrusions 622 includes first protrusions 622a having a width in the axial direction of the mixing rotor 6 larger than that in the circumferential direction, and second protrusions 622b having a width in the axial direction of the mixing rotor 6 smaller than that in the circumferential direction. First and second protrusion rows 623a and 623b are alternately arranged, the first protrusion rows 623a being formed of the first protrusions 622a aligned at a predetermined interval, the second protrusion rows 623b being formed of the second protrusions 622b aligned at a predetermined interval.

A bubble formation apparatus (500) includes: a rotor (100); a container (200) in which the rotor (100) is housed together with a liquid (LQ) and a gas (GS); and a rotary device (300) that causes rotation of the rotor (100) with the rotor (100) being pressed against an inner lower surface (221) that is the inner surface of the container (200). A bubble is formed by periodically repeating pressurization and depressurization of a mixture of the gas (GS) and the liquid (LQ) in a gap between the inner lower surface (221) and a portion, pressed against the inner lower surface (221), of the rotor (100) due to the rotation of the rotor (100) by the rotary device (300).