Synthesis and Liquid Crystalline Properties of Poly(ethylene oxide) Brushes with Amphiphilic Side Groups

Abstract

Summary: Poly(ethylene oxide)s containing decylthiomethyl (DTP), decylsulfonylmethyl (DSP), methyl‐oligo(ethylene oxide) thiomethyl (MnOTP), methyl‐oligo(ethylene oxide) sulfonylmethyl (MnOSP), decyl‐oligo(ethylene oxide) thiomethyl (DnOTP), and decyl‐oligo(ethylene oxide) sulfonylmethyl (DnOSP) groups in the side‐chains, where n (the number of ethylene oxide units) = 1, 2, 3, or 4 for DnOTP and DnOSP, and n = 2, 3, or 7 for MnOTP and MnOSP, were synthesized to study the effect of the structure of the side‐chains on the ordered phases of the polymers. All of the MnOSPs, as well as M2OTP and M3OTP, were found to be amorphous polymers. DTP, M7OTP, D1OTP, D2OTP, and D3OTP showed crystalline phases below their isotropic temperatures. DSP, D1OSP, D2OSP, D3OSP, D4OSP, and D4OTP were found to be liquid crystalline. Therefore, the phase separation facilitated by the introduction of the sulfone group and/or by the addition of the longer ethylene oxide units between the ethylene oxide backbones and the hydrophobic decyl tails was found to be a key factor in the formation of the liquid crystalline phases. These ordered phases were characterized using differential scanning calorimetry, polarized optical microscopy, and X‐ray diffraction.Schematic illustration of the structures of poly(ethylene oxide) brushes showing liquid crystalline phases.imageSchematic illustration of the structures of poly(ethylene oxide) brushes showing liquid crystalline phases.

Tacticity Effect on Mesogen-Free Liquid Crystalline Self-assembly Induced by Strong Dipole–Dipole Interactions

“…23,24 In addition to the alkyl side chains, ethylene oxide-based comblike polyethers were also synthesized. 25 If the side chain was only ethylene oxide based, an amorphous phase was found. However, by attaching the dodecyl group at the ethylene oxide chain end, smectic LC ordering with a double-layer structure was obtained.…”

Amphiphilic Comb‐Like Polymers Based on Poly(oxyethylene)s as Drug‐Delivery Carriers

“…PDI values of all the synthesized polymers were lower than poly(epichlorohydrin). Decreases in the molecular weight and the PDI values during polymer analogous reactions was previously reported although the reasons for this were not fully studied 31, 32. Cleavage of the polymer backbone could be such a reason.…”

“…As indicated by the DSC analysis, all the amphiphilic comb‐like polymers had single melting peaks. The melting transition should have been due to the side chain moieties because the polymer backbones had atactic amorphous configurations 17, 32. The melting temperature ( T m ) and change in enthalpy (Δ H ) of the polymers and side chain moieties are listed in Table 1.…”

Identification of single chain antibodies to breast cancer stem cells using phage display

“…Tri(ethylene glycol), 1‐bromodecane, sodium hydride (NaH), 3‐bromothiophene, iron(III) chloride, Copper(I) bromide (CuBr), and ammonium hydroxide (NH 4 OH) were purchased from Sigma–Aldrich and used without further purification. Decyl‐mono(ethylene oxide), decyl‐di(ethylene oxide), decyl‐tri(ethylene oxide), and decyl‐tetra(ethylene oxide) were synthesized as previously described 20. All other reagents and solvents were used as received.…”