3056-00-6Relevant articles and documents
Structure of monolayers of monododecyl dodecaethylene glycol at the air-water interface studied by neutron reflection
Lu,Su,Li,Thomas,Staples,Tucker,Penfold
, p. 10332 - 10339 (1997)
The structure of a monododecyl dodecaethylene glycol monolayer adsorbed at the air-water interface was determined at its critical micellar concentration by neutron reflection with deuterium labeling. The optical matrix method and the kinematic approximation gave structures identical within the limitations of the models used. In the optical matrix method, the monolayer was divided into the alkyl chain layer and a layer of the ethoxylated head, a fraction of the alkyl chain and water. Significant intermixing of the alkyl chain and ethoxylated headgroup was needed to account for the observed reflectivities. The distance between the centers of the alkyl chain and solvent distributions were found by the kinematic method.
Combinatorial synthesis of PEG oligomer libraries
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Page/Page column 10, (2010/02/15)
A simple chain-extending approach was established for the scale-up of the monoprotected monodisperse PEG diol materials. Reactions of THP-(OCH2CH2)n—OMs (n=4, 8, 12) with a large excess of commercially available H—(OCH2CH2)n—OH (n=1-4) under basic conditions led to THP-(OCH2CH2)n—OH (n=5-15). Similarly, Me-(OCH2CH2)n—OH (n=4-11, 13) were prepared from Me-(OCH2CH2)n—OMs (n=3, 7, 11). For the chain elongation steps, 40-80% yields were achieved through extraction purification. PEG oligomer libraries I and II were generated in 50-95% overall yields by alkylation or acylation of THP-(OCH2CH2)n—OH (n=1-15) followed by deprotection. Alkylation of Me-(OCH2CH2)n—OH (n=1-11, 13) with X—(CH2)m—CO2R (X=Br or OMs) and subsequent hydrolysis led to PEG oligomer library III in 30-60% overall yields. Combinatorial purification techniques were adapted to the larger-scale library synthesis. A total of 498 compounds, each with a weight of 2-5 g and a minimum purity of 90%, were synthesized.
