In physics|lang=en terms the difference between memcapacitor and memcapacitive

is that memcapacitor is (physics) a capacitor with memory, whose capacitance depends on past input while memcapacitive is (physics) that functions as a memcapacitor.

As a noun memcapacitor

is (physics) a capacitor with memory, whose capacitance depends on past input.

As an adjective memcapacitive is

(physics) that functions as a memcapacitor.