Block‐Selective Solvent Influence on Morphology of the Micelles Self‐Assembled by PS₃₈‐b‐P(AA₁₉₀‐co‐MA₂₀)

Abstract

Summary: The influence of block‐selective solvent on the self‐assembly of polystyrene‐block‐poly[(acrylic acid)‐co‐(methyl acrylate)] was studied. The nature of the block‐selective solvent, which is a binary solvent mixture with different composition, exerts remarkable influence on the morphology of the resulting micelles. When the block‐selective solvent is a binary solvent mixture of acetone and water with acetone content ranging from 0 to 90 vol.‐%, the resulting aggregates are core‐shell spheres with diameter about 60 nm, porous aggregates with diameter of 100, 180 and 250 nm, and core‐shell cauliflower‐like aggregates with size about 200 nm, respectively. The reason that the morphology of resulting micelles changes with acetone content has been discussed. The structure of the resulting micelles is further characterized in detail by DLS and SLS. Morphological tuning is also achieved by using a binary solvent mixture of ethanol and water or a binary solvent mixture of DMF and water as block‐selective solvent. In these cases, core‐shell spheres, hollow aggregates, and incompact aggregates are formed with the ethanol or DMF concentration ranging from 10 to 80 vol.‐%. magnified image

Novel Two‐Compartment Micelles Formed by Self‐Assembly of Linear Pentablock Copolymers in Selective Solvents

“…[10,[14][15][16][17] On the other hand, recent work on traditional micelles illustrates that varying the properties of solvent is a simple and efficient way to control the ordered structures formed by amphiphilic block copolymers. [18][19][20][21][22][23] However, to date most work on multicompartment micelles has focused on the discussion of the effects of copolymer architecture, [7][8][9][10][11] and investigation into the influence of solvent are very scarce.…”

Poly[(2-ethylhexyl acrylate)-ran-(tert-butyl acrylate)]-block-poly(2-cinnamoyloxyethyl acrylate) synthesis and properties

“…The easier accessibility of block copolymers by ATRP [3,4,5] has in turn helped fuel the study of block copolymer self-assembly in block-selective solvents. Block copolymers self-assemble into nanoaggregates with tens of morphologies ranging from spheres [6,7] to cylinders [8e10], tubes [11e15], vesicles [9,10,16e19], donuts [10,20,21], and many others [22].…”

Modulating the catalytic activity of Au/micelles by tunable hydrophilic channels

“…Styrene (St), 4-vinyl pyridine (4VP), t-butyl acrylate (tBA), N-isopropylacrylamide (NI-PAM), N,N 0 ,N 0 ,N 00 ,N 00 -pentamethyldiethylenetriamine (PMDETA), bipyridine, 2-Bromo-2-methylpropionyl bromide (BMPB, 98%), CuBr and CuCl were purchased from Aldrich and purified according to [25]. Tris [2-(dimethylamino)ethyl]amine (Me 6 TREN) was synthesized according to [26,27].…”

“…Then PS 455 -b-PAA 29 block copolymers can be obtained by the hydrolysis of PtBA block and the detailed hydrolysis process can be referred to Ref. 25. PNIPAM 172 -b-P4VP 73 and PEG 114 -b-P4VP 84 were synthesized by the polymerization of 4VP using CH 3 O-PEG 114 -Br (PEG 114 -Br) or PNIPAM-Cl as macro-initiator.…”

“…The detailed method of DLS can be found elsewhere. 25 Transmission electron microscopy (TEM) measurement was conducted by using a Philips T20ST electron microscopy at an acceleration voltage of 200 kV A small drop of solution was deposited onto a carbon-coated copper EM grid and dried at room temperature at atmospheric pressure. UV-vis spectra were recorded on a TU-8110 UV-vis spectrophotometer, equipped with two silicon diode detectors and a xenon flash lamp.…”