The current LEHN group is interested in four overlapping research themes:

Theme 1: Mechanistic nanotoxicology  

One of the most important challenges for the nanotechnology movement is to ensure the human health and environmental safety of its products.  This requires a fundamental understanding of how nanoscale structures interact with biological systems that range from biomolecules to lipid bilayers, cells, tissues and whole organisms.   Our group is interested in the chemistry and materials science at this rich bio-nano-interface.   We study the adsorption, dissolution, and biological reactivity of nanomaterial surfaces, and we collaborate with the A. Kane laboratory in Pathobiology to study cellular interactions of model nanomaterials synthesized and characterized in LEHN.   Our current focus is on carbon nanotubes [Liu et al., Small, 2011; Shi et al., Nature Nanotech. 2011] and graphene-family materials [Sanchez et al., Chemical Research in Toxicology, 2011; Liu et al., Small, 2011], which include graphene oxide and few-layer graphene with varying lateral dimension and layer number.  A long-term goal is to obtain sufficient understanding of the chemical mechanisms to rationally design and formulate nanomaterials for safety. (more related publications)

	Biological response to graphene-family materials: lung deposition and cell uptake [Sanchez et al, Chemical Research in Toxicology, 2011]

Theme 2: Nanomaterials and the natural environment

Nanomaterials will be increasingly released into the natural environment during manufacturing, use, or disposal.  We currently know very little about their transport, chemical transformation, ecotoxicity, and ultimate fate.  Our group is interested in the chemical transformations nanomaterials undergo in the natural environment, and the implications of those transformations for risk.  Our current focus is on nano-silver, CdSe quantum dots, and other metal-containing nanoparticles, and we are studying reactive dissolution, sulfidation, and chemical speciation in complex media found in both environmental and biological systems [Liu et al., ES&T, 2010, 2011; ACS Nano, 2011].  We are also interested in the applications of nanomaterials as sorbents [Johnson et al., 2008] and barriers to manage environmental toxicants. (more related publications)

Theme 3: Carbon materials and mesogenic materials

The Hurt laboratory has had a long-term interest in carbon materials as sorbents [Chen et al., 2003], structure materials, fuels [Lunden et al., 1998], and functional nanomaterials [Chan et al., 2005].  A special interest is in materials that pass through liquid crystal intermediates during their formation – so-called mesogenic materials.  The liquid crystal routes allow the establishment of long-range crystal order, the design of crystal orientations through surface anchoring and flow ordering [Hurt and Chen, Physics Today, 2000], and the ability to produce unique structures that cannot be produced by conventional methods.  We have developed new mesogenic materials made from carbonaceous mesophases [Chan et al., 2005], amphiphilic water-soluble dyes [Guo et al., Adv. Materials, 2011]) and aqueous lyotropic liquid crystals of graphene oxide [Guo et al., ACS Nano, 2011]. (more related publications)

Theme 4.  Synthesis and applications of 3D graphene architectures

Graphene oxide is a giant molecular plate-like precursor that can stack, fold and wrap, offering wholly new ways to fabricate advanced carbon materials [Guo et al., ACS Nano, 2011].  Our group is interested in the colloidal assembly of graphene oxide into 3D superstructures with applications as barriers, folded porous particles, stimuli-responsive materials that fold or unfold, wrapped graphene composities and electrode architectures for batteries and supercapacitors. (more related publications)