Program Highlights

May 21, 2012

Nanoscale Imaging of Wet Polymer Materials

Research
University of Massachusetts Amherst

The molecular- and nano-scale structure of bulk materials can be imaged only by transmission electron microscopy (TEM), a technique that requires high vacuum (low pressure). Until now, this constraint made TEM incompatible with ‘wet’ materials, such as molecules dispersed in a liquid or gels swollen by a solvent. Working at the Materials Research Science and Engineering Center (MRSEC) on Polymers at UMass Amherst, Hoagland, McCarthy, and Russell successfully imaged the fine structure of wet polymeric materials prepared with ionic liquids.

May 17, 2012

Inside a Crumpled Ball

Research
University of Massachusetts Amherst

The crumpling or crushing of paper, aluminum foil, or even a car fender is an everyday occurrence that is surprisingly rich in new physical and materials principles.  Working in the Materials Research Science and Engineering Center (MRSEC) on Polymers at the University of Massachusetts Amherst, Menon and Russell used X-ray microtomography experiments on foils crushed into a ball to understand their detailed 3D structure.

May 16, 2012

Responsive Wrinkles

Research
University of Massachusetts Amherst

Wrinkling, buckling, and creasing phenomena in synthetic and natural materials represents an opportunity to guide the placement of nanostructures that enhance the optical, mechanical, and/or electronic properties of materials.  Working in the Materials Research Science and Engineering Center on Polymers at UMass Amherst, Crosby discovered that reversible wrinkling can guide colloidal and nanoparticle assembly into well-ordered patterns across macroscopic length scales.

May 10, 2012

Conjugated Polymer Helices

Research
University of Massachusetts Amherst

 

Polymers having “conjugated structures”, allowing them to conduct electricity, hold great potential for flexible and ink-jet printable electronic devices and inexpensive plastic solar cells. Work by Hayward and Emrick in the Materials Research Science and Engineering Center (MRSEC) on Polymers at the University of Massachusetts Amherst has shown how to coax such polymers to twist into conducting wires thousands of times smaller than the twisted cables used in common electronic devices.

May 8, 2012

Creating a “repair-and-go” system using nanoparticle microencapsulation

Research
University of Massachusetts Amherst

Facile methods for detecting and repairing damaged regions of materials are critically important in numerous structural and functional materials, from airplane wings to fabrics to microelectronics to biological implant materials.  Emrick, Crosby, and Russell, working in the Materials Research Science and Engineering Center (MRSEC) on Polymers at UMass Amherst, demonstrated that microcapsules can carry nanoparticles across a damaged substrate, sense the damaged regions, and deposit nanoparticles selectively into the damaged areas, leaving the rest of the surface unaffected.

March 25, 2011

Ionic liquids as media for bioconjugation

Research
University of Massachusetts Amherst

thumbWater soluble polymers, once reserved for commodity applications (i.e., shaving cream, emulsification processes, etc.) have emerged as valuable materials for medicine.  Combining synthetic polymers with therapeutic proteins and cancer drugs improves the “therapeutic index” of the drugs, preventing their fast elimination from the body, and improving their availability for treating the disease.  Emrick at the UMass Materials Research Science and Engineering Center found that ionic liquids provide an excellent environment for the attachment of proteins to synthetic polymers.

March 11, 2011

Mesoscopically Helical Order in Chiral Block Copolymers

Research
University of Massachusetts Amherst

helical orderSupermolecular, helical assemblies are a common structural motif exploited in far-ranging biological contexts, from the flagellar appendages of swimming microorganisms to the protein coats that sheath rod-like viruses. The screw-like structure of these biological assemblies is a consequence of the chiral subunits (proteins and amino acids) from which they are built, and this chirality imbues the structures with a right- or left-handed sense or twist.

July 9, 2010

Assembly of Polymer-Functionalized Nanoparticles on Metal Droplets for Electronics

Research
University of Massachusetts Amherst

Dinsmore at the UMass Materials Research Science and Engineering Center demonstrated a simple and robust approach to fabricating nano-scale electrical contacts to nanoparticles. PEGfunctionalized nanoparticles assemble spontaneously on droplets of liquid metal; when two droplets are brought into contact, they remain separated by the nanoparticles at the interface (top figure). Junctions formed by this method show electron transport that is limited by the nanoparticles (bottom figure). The conductance can be tuned by a gate electrode to make transistors at the micronscale.

July 9, 2010

Education Outreach Programs at The Boston Museum of Science

Education
University of Massachusetts Amherst

A group of MRSEC researchers, staff, and graduate students visited the Boston Museum of Science on July 15, 2009 for a day of public demonstrations and presentations to encourage thought and discussion about polymers. The Ventures in Science Using Art Laboratory (VISUAL) program had an ongoing exhibit of images at the Museum from May through August, and coordinated a presentation to teach the audience about materials and capture their attention using visually striking images gathered during the course of MRSEC research at UMass.

March 21, 2009

Colloidosome Assemblies.

Research
University of Massachusetts Amherst

Rotello developed a very rapid and convenient method for fabricating microspheres with walls made of nanoparticles, known as colloidosomes. In this method alkyne and azide functionalized iron oxide nanoparticles are co-assembled at the water-in oil-interface and covalently linked using “click” chemistry under ambient conditions to create magnetic colloidosomes. These colloidosomes are highly stable in water, have size selective permeability, and are responsive towards external magnetic stimuli. Rotello and Dinsmore extended this process to develop stable NP self-assemblies at liquid-liquid interfaces. Terpyridine thiol (Terpy-SH) functionalized FePt NPs were self-assembled at the oil/water interface and simultaneously crosslinked at room temperature through complexation of terpyridine with Fe(II) metal ions, instantaneously affording stable membranes and colloidosomes. Tuning of the assembly process and application of this methodology to the creation of functional devices is underway.