Phase Separation Dynamics of Aqueous Poly [(2‐ethoxy) ethoxy ethyl vinyl ether] Solutions as Explored using the Laser T‐Jump Technique Combined With Photometry

Abstract

Poly[(2‐ethoxy) ethoxy ethyl vinyl ether] (poly(EOEOVE)) is a representative thermoresponsive polymer in aqueous solution for which the time constants of the phase separation (PS) are determined with high accuracy. It is revealed that the PS dynamics of the polymer are entirely different from those of the poly(N‐isopropylacrylamide) (PNIPAM) system, which is an alternative representative thermoresponsive polymer. Poly(EOEOVE) exhibits complicated PS behavior that is described using double exponential functions. The PS of poly(EOEOVE) is much faster than the PS of PNIPAM in aqueous solutions and becomes faster with increasing concentration of the polymer. PS behavior that is particular to the present system is successfully understood within the framework of the aggregation mechanism.

Rapid Phase Separation in Aqueous Solution of Temperature‐Sensitive Poly(N,N‐diethylacrylamide)

“…However, as you know, it is rather difficult to see stereostructure of polymers in solution Therefore, details are not discussed here. Such behavior with Type‐I aggregates has also been observed for poly(EOEOVE), in which two different rate components in the phase separation process have been observed …”

“…Actually, we can analyze the transmittance decay curves with a simple double‐exponential function as shown below. We found such behavior to be common to PNIPAM and poly [(2‐ethoxy) ethoxy ethyl vinyl ether] systems in our previous studies. For the PNIPAM measurements, we get a good fit with a single exponential function (Equation ).…”

“…Moreover, we also demonstrated that the phase separation dynamics strongly reflect the chemical structure of the polymer. We reported that polymer aggregation in a poly[(2‐ethoxy) ethoxy ethyl vinyl ether] (poly(EOEOVE)) system resulted in complicated phase separation behavior . Moreover, we discovered that phase separation for PNIPAM could be accelerated considerably by a slight modification of the stereoregularity of the polymer chains .…”

Thermoresponsive properties of 3-, 4-, 6-, and 12-armed star-shaped poly[2-(dimethylamino)ethyl methacrylate]s prepared by core-first group transfer polymerization

“…This can be reasonably explained by the enhanced entanglement among the polymer chains and the shortened diffusion time to get polymers aggregated largely because the inter-polymer distance decreases with increasing C. For a detailed explanation, refer to reports in the literature. 28,29 Sequentially, the T c -M w,MALS dependence of each type polymer was investigated at a xed mass concentration of 2.0 g L À1 since the M w,MALS is usually a key issue affecting the T c (Fig. 2a-f).…”

A method for an approximate determination of a polymer-rich-domain concentration in phase-separated poly(N-isopropylacrylamide) aqueous solution by means of confocal Raman microspectroscopy combined with optical tweezers

“…Since the phenomenon involves a wealth of physicochemical science and is applicable to biomedical engineering such as drug delivery [4], PNIPAM and related polymers have deeply been investigated by means of DSC [5,6], NMR [7,8], IR [9][10][11], and Raman spectroscopy [12]. It should be noted that kinetics and dynamics of such phase separation process are being recently revealed by our group using laser T-jump spectrometry [13,14] and single molecule tracking technique [15]. In spite of the past numerous studies, several important problems still remain unclear.…”