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Displaying 26 - 43 of 43

Co-Nonsolvency of Poly(n-isopropylacrylamide) in Deuterated Water/Ethanol Mixtures

September 25, 2013
Author(s)
Michael-Jon A Hore, Boualem Hammouda, Yuyan Li, He Cheng
Small-angle neutron scattering was used to investigate poly(N-isopropylacrylamide) (PNIPAM) polymer solutions in d-water /d-ethanol mixtures. A wide poor-solvent region was observed for mixtures near 60 % d-water/40 % d-ethanol mixture. Spinodal lines were

Temperature Effect on the Nanostructure of SDS Micelles in Water

April 11, 2013
Author(s)
Boualem Hammouda
Sodium dodecyl sulfate (SDS) surfactants form micelles when dissolved in water. These are formed of a hydrocarbon core and hydrophilic ionic surface. The small-angle neutron scattering (SANS) technique was used with deuterated water (D 2O) in order to

Influence of Organic Liquids on the Nanostructure of Precipitated Cellulose

February 15, 2013
Author(s)
Brian J. Watson, Boualem Hammouda, Robert M. Briber, Steven W. Hutcheson
Cellulose (β-1,4 glucose) crystallinity poses a substantial physical and economic barrier to the enzymatic digestion of biomass to its constituent sugars. The crystallinity of cellulose is an inherent property due to its synthesis as microfibrils as plant

Small-Angle Scattering from Branched Polymers

July 1, 2012
Author(s)
Boualem Hammouda
The single-polymer form factor is worked out for branched polynmers using a scaling argument in order to recover the low-Q Porod exponent characterisitc of the overall structure. The high-Q Porod exponent characterizes the local branching structure. An

The Conformation of Poly(ethylene glycol) Chains in Mono-PEGylated Lysozyme and Mono-PEGylated Human Growth Hormone

September 28, 2011
Author(s)
Sheetal S. Pai, Boualem Hammouda, Kunlun Hong, Danilo.C. Pozzo, Todd M. Przybycien, Robert D. Tilton
Covalent conjugation of poly(ethylene glycol) or "PEGylation" has proven an effective strategy to improvement pharmaceutical protein efficacy. Understanding the configuration of conjugated PEG chains is necessary to interpret the effect of PEG conjugation

SANS from Pluronic P85 in d-water

December 1, 2010
Author(s)
Boualem Hammouda
Small-angle neutron scattering (SANS) has been used to investigate pluronic P85 (EO 26PO 40EO 26) copolymer in deuterated water. A range of P85 fractions were measured for a wide sample temperature window. A rich phase behavior is reported. Unimers were

The Mystery of Clustering in Macromolecular Media

June 1, 2010
Author(s)
Boualem Hammouda
Clustering prevails in water-soluble polymers and biological macromolecules. It has also been observed in polar solvent mixtures. The possible causes of clustering are discussed. A systematic investigation of clustering in poly(ethylene oxide)/d-water

SANS from P85/Water-d Under Pressure

May 4, 2010
Author(s)
Bryna Clover, Boualem Hammouda
Pluronics are triblock copolymers of PEO-PPO-PEO. Pluronic P85 forms a rich phase behavior when dissolved in water. Unimers are observed at low temperature while micelles form at higher temperatures. Spherical, cylindrical and lamellar micelles are