Research

icon-silk.jpg Silks are natural polymers with outstanding properties. Some spider silks are tougher than the toughest synthetic polymers and even outperform steel in terms of strength by weight. Also, because it is a biocompatible protein, silk is ideally suited for use in biomedical applications.

The outstanding properties of silk are due to its interesting structure, featuring a peculiar organization down to molecular scales. We apply our imaging techniques to silkworm silk protein to provide unprecedented insights into assembly at single-molecule resolutions. This knowledge will help develop new processes to make silks artificially: novel materials that are environmentally completely benign and feature excellent mechanical properties.

Our lab also studies the brown recluse spider, which spins a thin ribbon of silk instead of a cylindrical strand typical of other species. By applying our imaging and other characterization techniques to this ribbon morphology, we hope to reveal novel structural, adhesive, and mechanical insights that will help us manufacture artificial thin silk films with the impressive properties of a native brown recluse strand.




icon-nanocomposites.jpg We embed nanoparticles into polymers in order to give these plastics new functionality. We currently focus on functionalized graphenes as nanofillers, with an emphasis on developing materials with excellent mechanical properties [10]. However, graphene can also be used to make rubber electrically conductive [14].

We developed several new techniques to directly measure the mechanical interaction strength between graphene particles and different polymers [15], [17]. This allows us to systematically develop new materials with improved strength and stiffness.

The described experimental techniques are enabling tools which we use for a new approach to nanocomposite development: away from the “trial & error” philosophy, and toward a systematic design of materials with predictable properties.




icon-graphene.jpg Graphene is the strongest and toughest material known to man, and it has outstanding electronic properties. Hannes Schniepp has been active in the graphene field since 2005. Some of his early publications in the field on chemically prepared functionalized graphene have since become citation classics [4], [7], [8], [10]. His graphene works have been cited 7208 times.

Currently, the research team investigates opportunities to exploit the outstanding electronic properties of graphene oxide for future optoelectronic applications, such as photovoltaics (funded by NSF).

We exploit the excellent mechanical properties of functionalized graphenes for nanocomposite applications.




icon-selfassembly.jpgIn the nanoworld, systems can be designed to self-organize into ordered structures. For engineering purposes, this phenomenon can be exploited to produce tiniest structures or for self-healing materials [5].

We currently investigate molecular-scale self-assembly using liquid-cell atomic force microscopy (AFM) [3], [5], [6], [9], [11], [12], [19], [21], [22], [27] for sensing applications and to reveal the structural secrets of silk, a complex, biological material.

Prof. Schniepp has a long-standing expertise in self-assembly of surfactant molecules at the solid—liquid interface [3], [5], [6], [9], [11], [12], [19], [21], [22], [27]. Surfactants often make micelle-like structures the on surface with feature size of just a few nanometers. These structures can be visualized using liquid-cell AFM, which is an excellent tool to study them. Surfactants are crucial in many applications, such as detergency, oil recovery, and corrosion inhibition [12]; they are also a self-healing model system [5].




icon-interfaces.jpg We are interested in interfacial forces at the solid–liquid interface as they govern many processes in various fields reaching from biomedical applications to petroleum engineering.

Interfacial forces at the solid–solid interface are important in composite and nanocomposite materials, where the strength of these interactions is crucial for the mechanical performance of the materials systems.

We directly probe interfacial interactions at the nanoscale using scanning probe techniques.




icon-implants.jpg A common problem in implants (hip implants, teeth) is that the attachment between the bone and the implant is imperfect. Ultimately, this leads to losening of the implant, which requires additional surgery.

Our team is investigating novel surface treatments of implant materials, which facilitate successful integration. This work is carried out incollaboration with Dr. Daniel E. MacDonald (PI) from the Hospital for Special Surgery in New York City, ranked several times as the #1 orthopedic hospital in the Unites States.

Previous Research Projects

Nanomaterials:

  • Bulk Production of Exfoliated Functionalized Graphene [6], [7], [8]

Self-Assembly:

  • Orientational Order of Self-Assembly on Molecular and Colloidal Length Scales [3], [5], [6], [9], [11], [12], [17]
  • Millisecond Self-Healing of Protective Surfactant Surface Layers [5]
  • Imaging Surfactant Surface Aggregates on Rough Surfaces [6], [11]
  • Tip-Induced Orientational Order of Surfactant Surface Micelles [9]

Scanning Probe + Optical Microscopy:

  • Development of a Microscope Integrating Scanning Probe and Confocal Fluorescence Approaches

Biophysics:

  • Scanning Probe Investigation of Native Nuclear Membranes in Suspended State
  • Conformation of DNA

Nanophotonics:

  • Experimental Study of Spontaneous Emission in Nanoparticles [1]
  • Shape- and Size-Dependence of Spontaneous Emission from Nanoparticles [2]
public/research.txt · Last modified: 2018/01/21 10:16 by schniepp