Macromol. Rapid Commun. 18/2009

Discriminating Among Co‐monomer Sequence Distributions in Random Copolymers Using Interaction Chromatography

“…Degree of polymerization of the adsorbing segments in PBr x S synthesized in CUD (DP ads ) and the equivalent DP of PBr x S synthesized in NB (DP eq ads ) corresponding to the retention times measured for PBr x S-CUD. [18] The discrepancy between DP ads and DP chromatographic column, the b-PBr x S chains only have a few unshielded 4-BrS segments available for adsorption. r-PBr x S coils, which are not as efficient in screening the repulsive interactions between 4-BrS and IO as b-PBr x S, adopt more loosely packed chain conformations.…”

“…The details will be provided in a subsequent publication. [18] In addition, by taking advantages of the monodispersity of the RCPs, we have calculated the values of DP ads , which represent the number of the ''available'' adsorbing segments in PBr x S-CUD. The values of DP eq ads contain important information to quantify the effectiveness of the adsorption of the PBr x S-CUD in comparison with the truly RCPs, because they represent the number of adsorbing segments for the PBr x S-CUD samples to exhibit the same IC retention times as for the PBr x S-NB samples.…”

Facile Method of Controlling Monomer Sequence Distributions in Random Copolymers

“…The same conclusions were reached from independent experiments using interaction chromatography, which revealed that no unbrominated PS was present in the solution. [29] In order to establish the degree of blockiness of 4-BrS in PBr x S-SOLtt, we utilized an electro-optical Kerr effect measurement in order to determine the molar Kerr constant, mK, which bears information about both the monomer stereoregularity and PS/4-BrS sequencing in PBr x S. [30,31] Guided by the experiments of Tonelli et al, [30,31] we anticipated that for PBr x S copolymers with similar 4-BrS distributions but increasing 4-BrS content, the mKs would increase with increasing 4-BrS content; and for PBr x S with the same 4-BrS composition but different sequence distribution, the mK would decrease with increasing blocky character of the monomer sequence distribution. In Figure 2c we plot the measured Kerr Table 1 we list the Kerr constant of 1 % (w/w) solution in 1,4-dioxane for three sets of the copolymer compositions.…”

Controlling Comonomer Distribution in Random Copolymers by Chemical Coloring of Surface-Tethered Homopolymers: An Insight from Discontinuous Molecular Dynamics Simulation

“…Lastly, system temperature kT/|ε AA | is regulated through the use of an Andersen thermostat. 25 In order to simulate the experimental coloring process, that is, the bromination of polystyrene, [10][11][12][13] M polymers comprising N square-well monomers each are attached to a surface at various surface densities, F. We define F = M/S, where M is the number of homopolymers and S is the area of the tethering surface in units of σ 2 . For our work, we have focused on two grafting densities: 0.001 and 0.010 polymers/area.…”

“…Recent work by Genzer and co-workers involved the formation of HAMS by exposing polystyrene chains to bromine. [10][11][12][13] By suitably controlling the solvent quality, poly(styrene-co-4-bromostyrene) HAMS were formed and then characterized by a suite of analytical methods. Unique bulk and interfacial properties associated with tuning comonomer sequences were also documented.…”