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We investigate a new kind of PVOH physical gel in which the volatile water is replaced with a non-volatile ionic liquid (IL). High melting IL containing Br- anion was chosen so that the hydrogen-bond accepting Br- can enhance miscibility with PVOH while
Santanu S. Kundu, Atul S. Bhangale, William E. Wallace, Kathleen M. Flynn, Charles M. Guttman, Richard Gross, Kathryn L. Beers
Enzymes immobilized on solid supports are increasingly used for chemical transformation because the process is greener and sustainable. Here we use microreactors to study enzyme catalyzed ring opening polymerization of -caprolactone to polycaprolactone. A
Young Jong Lee, Doyoung Moon, Kalman D. Migler, Marcus T. Cicerone
We demonstrate that broadband coherent anti-Stokes Raman scattering (CARS) microscopy can be very useful for fast acquisition of quantitative chemical images of multilayer polymer blends. Since a raw CARS signal results from coherent interference of
Joonsung (. Yoon, Hae-Jeong Lee, Christopher Stafford
We report the preparation and characterization of physical gels using mixtures of poly(vinyl alcohol) (PVOH) and a high melting ionic liquid (IL), 1-ethylpyridinium bromide. Similar to PVOH hydrogels, these mixtures show elastic responses in uniaxial
Peter M. Johnson, John A. Howarter, Christopher Stafford
Thin film indentation experiments on viscoelastic materials allowed for the deconvolution of the bulk compliance from interfacial responses at the buried interface. This technique could discriminate both large changes in the interfacial strength due to
John A. Howarter, Peter M. Johnson, Jun Y. Chung, Christopher Stafford
The delamination characteristics of patterned and hierarchical interfaces are of great interest due to the advanced adhesion capabilities found with many biological surfaces. Using nature-inspired design principles, micro- and nanostrucutred surfaces have
Robert C. Chang, Anant Agrawal, Peter M. Johnson, Christopher Stafford
In this work, we demonstrate a method to produce novel optical phantoms usable for the characterization of OCT axial resolution and contrast. By varying the diameter of the microspheres and the thickness of the polymer layers, different spatial frequencies
Yajun Cheng, Diana N. Zeiger, John A. Howarter, Xinran Zhang, Nancy Lin, Joseph M. Antonucci, Sheng Lin-Gibson
Nanocomposites of difunctional methacrylate polymer/silver nanoparticles have been synthesized by coupling photoinitiated free radical polymerization with in situ silver ion reduction. A polymerizable methacrylate bearing a secondary amino function group
Yajun Cheng, Joseph M. Antonucci, Steven Hudson, Nancy Lin, Xinran Zhang, Sheng Lin-Gibson
A new strategy to produce polymer-inorganic composites with ultra low volume shrinkage has been developed. Small amount of cavitation agent, acetone dicarboxylic acid (ADCA), was introduced into acrylate-glass composites and decomposed in situ to carbon
Lee J. Richter, Christine He, David Germack, R Joseph Kline, Dean DeLongchamp, Daniel A. Fischer, Chad R. Snyder, James G. Kushmerick
The nanoscale morphology of the active layer in organic, bulk heterojunction (BHJ) solar cells is crucial to device performance. Often a combination of casting conditions and post deposition thermal treatment are used to optimize the morphology. In general
Paul A. O'Connell, Greg B. McKenna, Edwin Chan, Christopher Stafford
Recently Chan et al. published a paper describing a method to use the wrinkling of a thin elastic film on which is adhered a thin polymer film to extract the viscoelastic properties of the polymer. Results were presented for the rubbery plateau modulus and
Carl G. Simon Jr., Kaushik Chatterjee, Laurence C. Chow, Limin Sun, Marian F. Young
There is a need to improve rapid methods for screening cell-biomaterial interactions. Current methods employ a flat 2D format even though 3D scaffolds are more representative of the tissue environment in vivo and cells are responsive to topological
Nancy J. Lin, Sheng Lin-Gibson, Jirun Sun, Yifu Ding
Surface topography is known to play a critical role in the biological response to materials, with surface features on the order of both microns and nanometers altering cell response, including morphology, adhesion, cytoskeletal orientation, and gene
Edwin P. Chan, Santanu S. Kundu, Qinhuang Lin, Christopher M. Stafford
The viscoelastic properties of polymer thin films can have a significant impact on the performance in many small-scale devices. In this work, we use thermal wrinkling, which is a phenomenon based on a thermally-initiated instability, to measure
Structural properties of polymeric scaffolds for bone tissue engineering play key role in directing osteogenesis. These properties depend on the chemical nature and the fabrication process of biomaterial. There are many protocols for fabricating scaffolds
Carl G. Simon Jr., Yanyin Yang, Shauna M. Dorsey, Murugan Ramalingam, Kaushik Chatterjee
We have developed a combinatorial platform for screening the effect polymer scaffold properties and composition on cell response. Traditional research involves preparing samples one at a time for characterization and testing. Combinatorial and high
A new kind of physical gels was prepared using the mixtures of poly(vinyl alcohol) (PVOH) and high melting ionic liquid (IL), 1-ethylpyridinium bromide. As the IL content was increased, the stiffness of the mixtures decreased sharply while extensibility
Jessica M. Torres, Nathan Bakken, Christopher Stafford, Jian Li, Bryan D. Vogt
The intrinsic flexibility of organic molecules has been suggested to enable bendable electronics in comparison to their stiffer, inorganic counterparts. However, very little is known regarding the mechanical properties of these conjugated molecular glasses
Carl G. Simon Jr., Sapun Parekh, Marcus T. Cicerone, Sheng Lin-Gibson, Kaushik Chatterjee, Marian F. Young
There is growing recognition cells can sense and respond to the mechanical properties of tissue scaffolds and that these interactions are critical in optimizing scaffold design [1-4]. Previous studies in planar 2D culture format have shown that human bone
Andrew A. Herzing, Lee J. Richter, Ian M. Anderson
The three-dimensional characterization of third generation photovoltaic device structures at the nanometer scale is essential to the development of efficient, reliable, and inexpensive solar cell technologies. Electron tomography is a powerful method for
Sheng Lin-Gibson, Jirun Sun, Nancy J. Lin, Jing N. Zhou, Hyun W. Ro, Christopher L. Soles, Marcus T. Cicerone, Yifu Ding
Understanding the correlation between cell contact guidance (CG) and nanoscale surface features is vital in designing advanced medical devices to manipulate cell behaviors. Nanoscale surface features that mimic extracellular matrix are critical
Douglas M. Fox, Mauro Zammarano, Jeffrey W. Gilman
Polyhedral oligomeric silsesquioxane (POSS) and cellulose were reacted in the ionic liquid, 1-ethyl-3-methylimidazolium acetate (EmiAc). Side reactions between the EmiAc and each reactant were prevalent, but use of water as the coagulating solvent produced
Darwin R. Reyes-Hernandez, Jennifer S. Hong, John T. Elliott, Michael Gaitan
A dielectrophoresis (DEP) microfluidic device that allows instantaneous trapping of cells for rapid return to cell growth conditions (within 5 minutes) and long-term cell experiments (cell proliferation, induction and differentiation) of embryonic P19
3D structural properties of polymeric scaffolds for tissue engineering play a key role in directing osteogenesis. In addition, much work has demonstrated that cell differentiation is sensitive to topology at sizes ranging from nano- to micro- to macroscale
Christopher Soles, Yifu Ding, H. Jerry Qi, Kyle J. Alvine, Hyun W. Ro, Dae Up Ahn, Jack Douglas, Sheng Lin-Gibson
Nanostructures created in polymer films by nanoimprint lithography are subject to large stresses, both those from the imprinting processes as well as stresses arising from the intrinsic thermodynamic instabilities. These stresses can induce nanostructure