School of Chemical and Biomedical Engineering Nanyang Technological University Loo Sun Sun Leslie  Assistant Chair (Academics) Assistant Professor  BS (Rice), PhD (MIT) Address: N1.2 B1-12 62 Nanyang Drive Singapore 637459 Tel: (65)-6790-6737  Email: SSLOO@NTU.EDU.SG

Academic history 

PhD (Chemical Engineering), Massachusetts Institute of Technology, 2000

BS (Chemical Engineering), Rice University, 1994

Professional experience

Assistant Professor, Nanyang Technological University (May 2004 to date)

Postdoctoral Associate, Massachusetts Institute of Technology (March 2000 – July 2003)

Professional associations

Tau Beta Pi

Phi Beta Kappa

Phi Lambda Upsilon

Research interests

- Polymer nanocomposites (layered silicate, nanoclay, montmorillonite)

- Structure-Property-Processing relationships (mechanical and thermal properties)

- Spectroscopic studies of polymer dynamics and interactions (solid-state NMR, FTIR, Raman)

Our group has been interested in studying the role of molecular structure and dynamics upon the properties of polymers and polymer nanocomposites. Organic-inorganic hybrid nanocomposites have shown potential for a wide range of applications due to their enhanced mechanical, thermal and electrical properties. However, while many hybrid systems have been characterized and properties evaluated, much current work is not systematic and addresses only macroscopic issues. There is still little understanding of how to put together an optimal organic-inorganic combination which will achieve a certain enhancement in nanocomposite properties. This is evidenced by the fact that not all nanocomposites demonstrated improvement in properties due to a lack of understanding of the basic interactions at the organic-inorganic interface. To date the nature of this interface is not well-characterized.

We have formulated our research thrusts in two different aspects: one is through the use of spectroscopic techniques and the other is through the fundamental study of molecular interactions at interfaces. In the first area, spectroscopic techniques are important for investigating molecular and surface properties at the nanoscale level. The nanoscale dimensions of the nano-particles require the use of instruments which can probe the nanoscale interactions between the particles and the polymer matrix. Spectroscopic techniques allow the discrimination of inter- and intra- molecular forces that exist between polymer and nanofillers. Furthermore, the strength of such interactions can also be studied. The use of solid state nuclear magnetic resonance (NMR) spectroscopy has allowed us to demonstrate the enhanced mobility of polymer chains during active tensile deformation (Loo et al., Science 2000). We have also employed Fourier transform infrared spectroscopy to elucidate the mechanics of deformation and thermal degradation in polymer/nanoclay nanocomposites (Zhang and Loo, Polymer 2009; Loo and Gleason, Macromolecules 2003).

In the second area, we have formulated model systems in which we can better ascertain the role played by interfaces in affecting the performance of polymer nanocomposites. Recently, we have demonstrated with our model system of the different effectiveness of nano-fillers (montmorillonite) in enhancing the mechanical properties of fully amorphous versus semi-crystalline polymers (Zhang and Loo, Macromolecules 2009). We have also succeeded in using Langmuir-Blodgett technique to deposit layered silicate onto a polymeric surface and studied its properties (Zhou and Loo, accepted by J. Colloid & Interface Sci. 2009).

From our work, we endeavour to produce organic-inorganic nanocomposites with better properties by intelligent manipulation of the interfacial interactions. This will have a great impact on the design of new materials with novel applications.

Prizes and Awards

Nanyang Award (Excellence in Teaching) 2007

Tau Beta Pi Fellow

AIChE Scholastic Achievement Award

Courses taught

CH1006 Mathematics for engineers A

CH2003 Fluids systems

CH3007 Computational methods for chemical engineers

Papers

Zhou Q, Wang K, Loo LS, (2009). “Synthesis of novel hybrid films of a layered silicate and alkylammonium cations on rough polymeric surfaces by Langmuir–Blodgett method,” Journal of Colloid and Interface Science 340, 249-253.

Zhang XG, Loo LS, (2009). “Study of Glass Transition and Reinforcement Mechanism in Polymer/Layered Silicate Nanocomposite,” Macromolecules 42, 5196-5207.

Zhang XG, Loo LS, (2009). “Synthesis and thermal oxidative degradation of a novel amorphous polyamide/nanoclay nanocomposite,” Polymer 50, 2643-2654.

Zhou Q, Loo LS, (2009). “Abrasion studies of nylon 6/montmorillonite nanocomposites using scanning electron microscopy, Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy,” Journal of Applied Polymer Science 113, 3286-3293.

Zhang XG, Loo LS, (2008). “Morphology and Mechanical Properties of a Novel Amorphous Polyamide/Nanoclay Nanocomposite,” Journal of Polymer Science Part B-Polymer Physics 46, 2605-2617.

Kenneth K.S. Lau, Yu Mao, Hilton G. Pryce Lewis, Shashi K. Murthy, Brad D. Olsen, Leslie S. Loo and Karen K. Gleason, (2006). “Polymeric nanocoatings by hot-wire chemical vapor deposition (HWCVD),” Thin Solid Films 501, 211-215.

Loo LS, Gleason KK, (2004). “Investigation of polymer and nanoclay orientation distribution in nylon 6/montmorillonite nanocomposite,” Polymer 45, 5933-5939.

Loo LS, Gleason KK, (2003). “Insights into structure and mechanical behavior of a and g crystal forms of nylon 6 at low strain by infrared studies,” Macromolecules 36, 6114-6126.

Loo LS, Gleason KK, (2003). “Fourier Transform Infrared Investigation of the Deformation Behavior of Montmorillonite in Nylon 6/nanoclay Nanocomposite,” Macromolecules 36, 2587-2590.

Loo LS, Gleason KK (2001). “Hot filament chemical vapor deposition of polyoxymethylene as a sacrificial layer for fabricating air gaps,” Electrochemical and Solid State Letters 4, G81-G84.

Loo LS, Cohen RE and Gleason KK, (2000). “Chain Mobility in the Amorphous Region of Nylon 6 under Active Uniaxial Deformation Observed by Deuterium Nuclear Magnetic Resonance,” Science 288, 116.

Gleason KK, Loo LS, Cohen RE, (Mar 2000). “Deuterium NMR of nylon-6 rods undergoing large-strain tensile deformation,” Abstr. Pap. Am. Chem. S. 219, 32-PMSE Part 2.

Loo LS, Cohen RE and Gleason KK, (2000). “Deuterium nuclear magnetic resonance of deuterium oxide in nylon 6 under active uniaxial deformation,” Polymer 41, 7699.

Loo LS, Cohen RE and Gleason KK, (1999). "Deuterium nuclear magnetic resonance of phenol-d₅ in nylon 6 under active uniaxial deformation,” Macromolecules 32, 4359.

Loo LS, Cohen RE and Gleason KK, (1998). "Correlation Times of Motion of Deuterium Oxide in Polyamide 6 rods," Macromolecules 31, 8907.