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Search Publications by: Edwin P Chan (Fed)

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Displaying 26 - 50 of 57

Signatures of intracrystallite and intercrystallite limitations of charge transport in polythiophenes

September 20, 2016
Author(s)
Kiarash Vakhshouri, Brandon Smith, Edwin Chan, Chenchen Wang, Alberto Salleo, Cheng Wang, Alexander Hexemer, Enrique Gomez
Charge carrier mobilities in conjugated semicrystalline polymers depend on morphological parameters such as crystallinity, crystal orientation, and connectivity between ordered regions. Despite recent progress in the development of conducting polymers, the

Tailor-Made Polyamide Membranes for Water Desalination

December 30, 2014
Author(s)
Edwin P. Chan, Wansuk Chol, Joona Bang, Jong Suk Lee, Jung-Hyun Lee, Joung-Eun Gu
Independent control over the extrinsic and intrinsic properties of the polyamide selective layer is critical when designing water desalination reverse osmosis (RO) membranes with performance characteristics required for water purification applications

Tailoring the Permselectivity of Water Desalination Membranes via Nanoparticle Assembly

January 6, 2014
Author(s)
Edwin Chan, William Mulhearn, Jung-Hyun Lee, Daeyeon Lee, Christopher Stafford
: Thin film composite membranes can selectively separate mono- and di-valent ions from water via solution-diffusion of each species through a dense but ultrathin, highly crosslinked polymer ‘skin' layer - water is transported across the membrane faster

Swelling of Ultrathin Molecular Layer-by-Layer Polyamide Water Desalination Membranes

September 30, 2013
Author(s)
Edwin P. Chan, Allison P. Young, Jung-Hyun Lee, Christopher M. Stafford
The water vapor swelling behavior of ultrathin crosslinked aromatic polyamide films, synthesized via molecular layer-by-layer deposition, is characterized via specular X-ray reflectivity. The results show that these films expand only along the thickness

Molecular Layer-by-Layer Assembled Reverse Osmosis Membranes for Water Desalination

July 12, 2013
Author(s)
Joung-Eun Gu, Seunghye Lee, Wansuk Choi, Jong Suk Lee, Bo-Young Kim, Edwin Chan, Christopher Stafford, Jun-Young Chung, Joona Bang, Jung-Hyun Lee
Here, we report on the successful design, construction, and performance of membranes constructed using the mLbL process and show that these membranes exceed the performance of membranes synthesized through conventional interfacial polymerization. In our

Mechanochromic photonic gels

June 10, 2013
Author(s)
Edwin P. Chan, A M. Urbas, Joseph J. Walish, Edwin L. Thomas
Polymer gels are remarkable materials with physical structures that can adapt significantly and quite rapidly with changes in the local environmental changes such as temperature, light intensity, electrochemistry, and mechanical force. An interesting

Swelling of ultrathin crosslinked polyamide water desalination membranes

December 27, 2012
Author(s)
Edwin P. Chan, Allison P. Young, Jung-Hyun Lee, Jun-Young Chung, Christopher M. Stafford
We study the water swelling behavior of semi-aromatic crosslinked polyamide ultrathin films in order to characterize the materials properties of the polymer network. Specifically, we utilize X-ray reflectivity and quartz crystal microbalance to measure

Viscoelastic and poroelastic relaxations of polymer-loaded hydrogels

July 5, 2012
Author(s)
Blessing Deeyaa, Christopher Stafford, Edwin Chan, Peter M. Johnson
In this work, we study the viscoelastic and poroelastic contributions on the relaxation behavior of a polymer-loaded hydrogel using a recently develop Poroelastic Relaxation Indentation (PRI) measurement technique. By applying a generalized relaxation

Synthesis and characterization of model crosslinked polyamide films for water purification

June 24, 2012
Author(s)
Peter M. Johnson, Edwin Chan, Jun Y. Chung, Junghyun Lee, Christopher Stafford
Reverse osmosis (RO) and nanofiltration (NF) membranes are comprised of a dense active layer supported by a porous support. Commercial active layer are highly crosslinked polyamides that are formed through interfacial polymerization directly on the support

Spherical indentation testing of poroelastic relaxations in thin hydrogel layers

December 16, 2011
Author(s)
Edwin Chan, Yuhang Hu, Peter M. Johnson, Zhigang Suo, Christopher Stafford
In this work, we present the Poroelastic Relaxation Indentation (PRI) testing approach for quantifying the mechanical and transport properties of thin layers of poly(ethylene glycol) hydrogel materials with thicknesses on the order of 200 m. Specifically

Block copolymer photonic gel for mechanochromic sensing

September 19, 2011
Author(s)
Edwin Chan, Joseph J. Walish, Edwin L. Thomas, Christopher Stafford
In this work, we describe a strategy based on mechanochromic sensing, the coupling between mechanical and optical properties, of a block copolymer photonic gel. Although this phenomena has been observed in many materials, we demonstrate this concept for

Comment on Viscoelastic properties of con ned polymer lms measured via thermal wrinkling by Edwin P. Chan, Kirt A. Page, Se Hyuk Im, Derek L. Patton, Rui Huang and Christopher M. Stafford, Soft Matter (Communications), 5, 4638 4641 (2009).

January 11, 2011
Author(s)
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