Publications

Displaying 51 - 75 of 217

PEG-HYDROGELS: SYNTHESIS, CHARACTERIZATION, AND CELL ENCAPSULATION

September 15, 2009

Author(s)

Sheng Lin-Gibson, Kaushik Chatterjee, James A. Cooper, William E. Wallace, Matthew Becker, Carl G. Simon Jr., Ferenc Horkay

A simple reaction to prepare controlled molecular mass (MM) poly(ethylene glycol) dimethacrylates (PEGDMs) of high purity and low polydispersity is outlined. PEGDMs were photo-polymerized to form hydrogels with and without bioactive moieties. The structure

A General Method for the Quantitative Measurement of Molecular Mass Distribution by Mass Spectrometry

September 1, 2009

Author(s)

Eun S. Park, William E. Wallace, Charles M. Guttman, Kathleen M. Flynn, Mickey Richardson, Gale A. Holmes

A method is presented to test whether the conversion of the mass spectrum of a polydisperse analyte to its molecular mass distribution is quantitative. Mixtures of samples with different average molecular masses, coupled with a Taylor's expansion

Combinatorial Screening of Hydrogel Properties for 3-D Cell Culture: Effect of Stiffness on Encapsulated Osteoblasts

July 15, 2009

Author(s)

Carl G. Simon Jr., Kaushik Chatterjee, Sheng Lin-Gibson, William E. Wallace, Marian F. Young

A combinatorial method to rapidly screen cell-material interactions in three-dimensional (3-D) culture format was developed for accelerating tissue engineering research. Hydrogels of poly(ethylene glycol) dimethacrylate (PEGDM) with gradients in

Quantitative Measurement of the Polydispersity in the Extent of Functionalization of Glass Forming Resorcinarenes

May 1, 2009

Author(s)

William E. Wallace, Kathleen M. Flynn, Charles M. Guttman, David L. VanderHart, Vivek M. Prabhu, Anuja De Silva, Nelson Felix, Christopher K. Ober

The polydispersity in the degree of functionalization for two calix[4]resorcinarenes was determined by measuring their molecular mass distribution with matrix-assisted laser desorption/ionization time of flight mass spectrometry. A mathematical method for

Rapid Screening of Hydrogel Properties for 3D Tissue Culture: Effect of Modulus on Encapsulated Osteoblasts

April 25, 2009

Author(s)

Kaushik Chatterjee, Sheng Lin-Gibson, Marian F. Young, William E. Wallace, Carl Simon Jr.

Statement of Purpose: With few successful products in the market despite large investments in tissue engineering research, there is a need to accelerate tissue engineering research. Towards this objective, developing high-throughput platforms to rapidly

Quantitative Mass Spectrometry and Polydisperse Materials: Creation of an Absolute Molecular Mass Distribution Polymer Standard

December 12, 2008

Author(s)

Charles M. Guttman, Kathleen M. Flynn, William E. Wallace, Anthony J. Kearsley

The certification of an absolute molecular mass distribution polymer Standard Reference Material is described. SRM 2881 is an n octyl initiated, proton terminated, narrow polydispersity, low mass, atactic polystyrene. The absolute molecular mass

2,5-Dihydroxybenzoic Acid: Laser Desorption/Ionization as a Function of Elevated Temperature

September 11, 2008

Author(s)

William E. Wallace, Mark Arnould, R Knochenmuss

A Report on the Certification of an Absolute Molecular Mass Distribution Polymer Standard: Standard Reference Material 2881

September 11, 2008

Author(s)

Charles M. Guttman, Kathleen M. Flynn, William E. Wallace, Anthony J. Kearsley

The certification of an absolute molecular mass distribution polymer Standard Reference Material, SRM 2881, is described. SRM 2881 is an n octyl initiated, proton terminated, narrow polydispersity, low mass, atactic polystyrene. The absolute molecular mass

Lessons Learned From NIST's Two Recent Polymer MS Interlabortaory Comparisons

September 11, 2008

Author(s)

Kathleen M. Flynn, William E. Wallace, Stephanie J. Wetzel, David L. VanderHart

Lessons learned from NIST two previously-published round robins are collected in one place and examined for commonalities.

Reactive MALDI Mass Spectrometry: Application to High Mass Alkanes and Polyethylene

August 21, 2007

Author(s)

William E. Wallace

A molecular solid of fullerene (C60) intercalated with cobalt cyclopentadienyl dicarbonyl (CoCp(CO)2) was shown to be an effective matrix for matrix-assisted laser desorption/ionization mass spectrometry (MALDI) of large alkanes (demonstrated up to C94H190

Degradation of Polymeric Ballistic Materials

June 7, 2007

Author(s)

Eun S. Park, Kathleen M. Flynn, Gale A. Holmes, Charles M. Guttman, William E. Wallace

Numerical Optimization of Matrix-Assisted Laser Desorption/Ionization Time-of- Flight Mass Spectrometry: Application to Synthetic Polymer Molecular Mass Distribution Measurement

May 26, 2007

Author(s)

William E. Wallace, Charles M. Guttman, Kathleen M. Flynn, Anthony J. Kearsley

A novel approach is described for the selection of optimal instrument parameters that yield a mass spectrum which best replicates the molecular mass distribution of a synthetic polymer. The application of implicit filtering algorithms is shown to be a

Matrix-Assisted Laser Desorption/Ionization Mass Spectrometry of Covalently-Cationized Polyethylene as a Function of Sample Temperature

January 1, 2007

Author(s)

William E. Wallace, William R. Blair

A pre charged, low mass, low polydispersity linear polyethylene was analyzed with matrix assisted laser desorption/ionization (MALDI) mass spectrometry as a function of sample temperature between 25 C and 150 C. This temperature range crosses the

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