Dr Xiangbing Zeng
Address:
Department of Materials Science and Engineering
Sir Robert Hadfield Building
Mappin Street, Sheffield, S1 3JD
Telephone: +44 (0) 114 222 5948
Fax: +44 (0) 114 222 5943
Email: x.zeng@sheffield.ac.uk
Xiangbing Zeng was appointed as Lecturer in Polymers and Liquid Crystals in October 2003. Previously he was a research assistant in the Polymer, Liquid Crystal and Supramolecular Structures Group in this department. He obtained his PhD degree from the University of Sheffield in 2001.
Research interests
His research concerns 1-d, 2-d, 3-d ordered nano-structures (1 – 100 nm) in macromolecular and supramolecular systems, with implications for photonic and molecular electronic materials. The main methods used are small angle x-ray and neutron scattering (SAXS and SANS). These experiments are often carried out in real-time in order to catch transient structures and rapid transformations during processes such as polymer crystallization or thermal treatment.
Key projects
- Ultralong chain n-alkanes and their mixtures. These are extremely long chains, strictly uniform in lengths, which makes them ideal models for polymers. Studies on these alkanes have revealed a variety of lamellar structures. The picture on the right shows an example: the stable high-temperature semicrystalline lamellar structure in binary alkane mixtures.
- Combined SAXS/SANS. The chain ends of alkane molecules can be highlighted for neutron scattering by selective deuteration. Using a combination of SAXS and SANS, the semicrystalline structures of polymers can be examined in unprecedented detail.
- Real-time SANS. This is a novel method for studying crystallization of polymers and other materials. The method is particularly useful where transient intermediary states are involved. This opens up a new way of monitoring structure formation under industrial processing conditions.
http://www.isis.rl.ac.uk/largescale/loq/technical/T_Jump_Expt2.htm - Complex supramolecular structures. Another area of interest is self-assembly of dendrimers (tree-like molecules) and other liquid crystal forming molecules. Such molecules assemble into columns or spheres, which in turn pack forming complex 2-d and 3-d periodic structures. Research in this area has led to discoveries such as the first quasicrystalline structure in liquid crystals and novel honeycomb network structures formed by T-shaped molecules.
Professional activities and recognition
- Member of EPSRC College
- Member of Institue of Physics
- Visiting scientist (1 month) at Laboratoire Physique Solides, Universite Paris-Sud, Orsay, June, 2006
- Recent Invited talks
o International Conference on Neutron and X-ray Scattering, Indonesia, 2007
o Quasicrystals, the Silver Jubilee, Israel 2007
o Aperiodic 2006, Japan - British Liquid Crystal Society Young Scientist of the Year 2006
Key publications
- X.B. Zeng, Y.S. Liu, M. Imperor-Clerc, Hexagonal close packing of nonionic surfactant micelles in water, J. Phys. Chem. B, 111, 5174-5179, (2007).
- X.B. Zeng, G. Ungar, S.J. Spells, S.M. King, Real-Time Neutron Scattering Study of Transient Phases in Polymer Crystallization, Macromolecules, 38, 7201-7204, (2005).
- X.B. Zeng, G. Ungar, M. Imperor-Clerc, A triple-network tricontinuous cubic liquid crystal, Nature Materials, 4, 562-567, (2005).
- B. Chen, X.B. Zeng, U. Baumeister, S. Diele, G. Ungar and C. Tschierske, Liquid Crystalline Networks Composed of Pentagonal, Square, and Triangular Cylinders, Science, 307, 96-99, (2005).
- X.B. Zeng, G. Ungar, Y.S. Liu, V. Percec, A.E. Dulcey, J.K. Hobbs, Supramolecular dendritic liquid quasicrystals, Nature, 428, 157-160, (2004).
- X.B. Zeng, G. Ungar, S.J. Spells, G.M. Brooke, C. Farren and A. Harden, Crystal-amorphous polymer interface studied by neutron and X-ray scattering on labelled binary ultralong alkanes, Phys. Rev. Lett., 90, 155508, (2003).
Research group
PDRAs
Alan Fowler
PhD Students
Feng Liu
Fangning Xie (co-supervise with Prof. G. Ungar)
Jitrin Chaiprapa (co-supervise with Prof. G. Ungar)
Christa Weber (co-supervise with Prof. G. Ungar and Dr. J. Hobbs)