polymers Article Sponge-Like Water De-/Ad-Sorption versus Solid-State Structural Transformation and Colour-Changing Behavior of an Entangled 3D Composite Supramolecuar Architecture, [Ni4(dpe)4(btc)2(Hbtc)(H2O)9]·3H2O Chih-Chieh Wang 1,* , Szu-Yu Ke 1, Kuan-Ting Chen 1, Ning-Kuei ...