Shan Cheng

Mimicking bone nanostructure by combining block copolymer self-assembly and 1D crystal nucleation.

The orientation and spatial distribution of nanocrystals in the organic matrix are two distinctive structural characteristics associated with natural bone. Synthetic soft materials have been used to successfully control the orientation of mineral crystals. The spatial distribution of minerals in a synthetic scaffold, however, has yet to be reproduced in a biomimetic manner. Herein, we report using block copolymer-decorated polymer nanofibers to achieve biomineralized fibrils with precise control of both mineral crystal orientation and spatial distribution. Exquisite nanoscale structural control in biomimetic hybrid materials has been demonstrated.

Polymer single crystal-decorated superhydrophobic buckypaper with controlled wetting and conductivity.

Herein we report fabrication of uniform, free-standing nanohybrid buckypaper with high carbon nanotube (CNT) contents (13-70%) using polymer single crystal-decorated CNTs as the precursor. Polyethylene single crystals were periodically grown on CNT surfaces, forming a nanohybrid shish kebab (NHSK) structure. Vacuum filtering a NHSK suspension led to polymer single crystal-decorated buckypaper (named as NHSK paper) with a wide range of CNT contents and uniform CNT dispersion. Porosity, surface roughness, and conductivity of NHSK paper can be controlled by tuning the polymer single crystal size. Because of the hierarchical roughness created by intra- and inter-NHSK nanostructure, NHSK paper with controlled kebab size exhibits both superhydrophobicity and high surface water adhesion, which mimics the rose petal effect. We anticipate that this unique NHSK paper can find applications in sensors, electrochemical devices, and coatings.

Anisotropic ion transport in nanostructured solid polymer electrolytes

Solid polymer electrolytes (SPEs) with good room temperature ionic conductivity and a high shear modulus are needed for future energy storage devices. Extensive studies have been devoted to searching for SPE with these desired properties. In this review, we will discuss recent progresses on the correlation between nanoscale morphology and ion conductivity in SPEs. Specifically, we will focus on anisotropic ion transport in five different types of SPEs with distinct morphological controls: crystalline structure, block copolymers, mechanical stretching, hybrids/nanocomposites, and holographic polymerization.