Research

Aiming to develop the next generation nanocomposite system with lighter weight, higher strength, and more intelligent for versatile applications such as ballistic protection, sensing, nanocatalysis, Prof. Liu’s current research directions include:

(1) Polymer Nanocomposites with 2D Materials

We recently developed a dimension-increase processing strategy including 4j folding/stacking and transverse shear scrolling to fabricate mechanically robust and multifunctional layered planar stacks and Archimedean spiral fibers with aligned semi-infinite two-dimensional (2D) materials (e.g., graphene), see papers: (1) P. Liu, M. Strano*, et al. Science, 2016, 353, 6269 and (2) P. Liu, M. Strano*, et al. Nano Today, 2018, 21, 18. for details. Our further calculation shows that these nanocomposites can be used as lightweight and high-strength armor materials to enable the concept of “ambient armor” concept for projectile protection (P. Liu and M. S. Strano*, Adv. Funct. Mater., 2016, 26, 943.), and their integration with robotic platforms could further allow the development of the autonomous anti-ballistic platform (P. Liu and M. S. Strano* et al., Robotic Systems and Autonomous Platforms, P493-521).

(2) Synthetic Cells or Particulate Electronic Devices

Two-dimensional (2D) materials like graphene possess desirable mechanical and functional properties for incorporation into or onto novel colloidal particles, potentially granting them unique electronic functions and extending nano/microelectronics into previously inaccessible environments. However, this application has not yet been realized because conventional top-down lithography scales poorly for the production of colloidal solutions.  Recently we developed an autoperforation method to assemble 2D materials-wrapped particulate electronic devices or colloidal state machines as aerosolizable electronics and dispersible & recoverable microprobes capable of collecting and storing digital and chemical information. See papers P. Liu, Albert Tianxiang Liu, M. Strano*, et al. Nature Materials, 2018, 17, 1005 (cover article). and V. B. Koman, P. Liu, M. Strano*, et al., Nature Nanotechnology, 2018, 13, 819., and book chapter JF Yang, P. Liu, V. B. Koman, AT Liu, MS Strano* Robotic Systems and Autonomous Platforms, 361-386 for details.

(3) Polyolefins & functional polyolefins and polymer reaction engineering

We are also working on the precise synthesis of ethylene copolymers with tailor-made chain topologies and functionalities by means of polymer reaction engineering and their characterization, including long-chain branched polyolefins, hyperbranched polyethylenes (HBPEs), functionalized HBPEs, and their application as nanocatalyst or organocatalyst support:

For long-chain branched polyolefins, please see (1) Macromolecules 51 (21), 8790-8799, (2) Macromolecular Reaction Engineering 10, 156-179, (3)
Macromolecular Reaction Engineering 10, 180-200, and (4) Macromolecular Reaction Engineering 11, 1600012. For hyperbranched polyethylene (HBPE), functionalized HBPE, and their applications as nanocatalyst or organocatalyst support, please see (1) Catalysis Science & Technology 2015, 5 (7), 3798-3805., (2) Polymer Chemistry 2014, 5 (18), 5443-5452., (3) J. Mater. Chem. A 2013, 1 (48), 15469-15478., (4) Macromolecules 2013, 46 (1), 72-82., (5) Progress in controlled radical polymerization: mechanisms and techniques 2012, 4, 39–64., (6) Macromolecules 2011, 44 (11), 4125-4139., and (7) Journal of Polymer Science Part A: Polymer Chemistry 2010, 48 (14), 3024-3032.

(4) Stimuli-responsive polymers or microgels

We are also working on the CO2/N2-responsive polymers and microgels and their applications as recyclable nanoreactors and emulsion stabilizer, representative publications include: ACS Applied Nano Materials 2018, 1 (3), 1280-1290, (2) Langmuir 30 (34), 10248-10255., and (3) Green Materials 2014, 2 (2), 82-94.