Stepwise Crosslinking: A Facile Yet Versatile Conceptual Strategy to Nanomorphology-Persistent Porous Organic Polymers.

Abstract

Both high surface areas and well-orchestrated nanomorphologies are important for porous organic polymers (POPs). However, the two key characteristics are generally difficult to be satisfied simultaneously, because the common pore-making procedures usually produce ill-defined nanomorphologies or give rise to damage of precustomized nanomorphologies. Herein, a facile yet versatile stepwise crosslinking strategy for fabrication of POPs with an unusual nanomorphology-persistent characteristic during pore-making is reported. Polystyrene nanofibers and poly(styrene-co-divinylbenzene) nanosphere arrays are utilized as building blocks, and then transformed into nanofibrillar morphology-persistent and ordered array morphology-persistent POPs via stepwise crosslinking, respectively. The stepwise crosslinking strategy includes pre-crosslinking and hypercrosslinking; the pre-crosslinking in a carefully selected poor solvent of polystyrene forms a lowly crosslinked structure, which guarantees the stability of nanomorphology during the subsequent pore-making via hypercrosslinking. The as-obtained POPs can be used as precursors for novel well-defined hyperporous carbon nanofibers and ordered carbon nanosphere arrays with excellent adsorption performances.