Structure of adsorbed layers of ethylene glycol monododecyl ether surfactants with one, two, and four ethylene oxide groups, as determined by neutron reflection

Langmuir ◽  
1993 ◽  
Vol 9 (9) ◽  
pp. 2408-2416 ◽  
Author(s):  
J. R. Lu ◽  
Z. X. Li ◽  
T. J. Su ◽  
R. K. Thomas ◽  
J. Penfold
Keyword(s):  
Ethylene Oxide ◽  
Ethylene Glycol ◽  
Neutron Reflection ◽  
Adsorbed Layers

Irreversible Adsorption of Polymer Melts

1996 ◽  
Vol 464 ◽  
Author(s):  
U. Sawhney ◽  
C.J. Durning ◽  
B. O'Shaughnessy ◽  
G.S. Smith ◽  
J. Majewski
Keyword(s):  
Room Temperature ◽  
Adsorbed Layer ◽  
Equilibrium Structure ◽  
Pmma Film ◽  
Irreversible Adsorption ◽  
Equilibrium Conditions ◽  
Melt Structure ◽  
Neutron Reflection ◽  
Reflection Data ◽  
Adsorbed Layers

ABSTRACTWe studied the equilibrium architecture of polymer layers strongly adsorbed from the melt. Immobilized layers of poly-(methyl methacrylate) (PMMA) were produced by the following method: 1) The polymer was spin-coated onto silanol bearing surfaces of single crystal and fused quartz, and annealed at melt conditions, 2) The annealed layer was quenched to room temperature (below the glass transition temperature) in order to “freeze in” the melt structure near the substrate, 3) Unbound material was leached away in good solvent (benzene) to leave a residual, strongly-adsorbed layer. The architecture of this layer was studied by neutron reflection. Data on dried adsorbed layers indicates a dense PMMA film whose thickness gradually increases with annealing time in the melt from a minimal value. Evidently, annealing gradually relaxes a rather flat non-equilibrium structure produced by spin-coating. The thicknesses, h, in a series of dry layers annealed long enough to achieve equilibrium conditions in the melt scale as h ∼ N1/2. Data on swollen layers suggest a dilute, extended layer, but the preliminary results cannot give a definitive confirmation of the brush structure predicted by Guiselin.11

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