Thermoreversible gelation and phase separation in aqueous methyl cellulose solutions

Laser speckle analysis on correlation between gelation and phase separation in aqueous methyl cellulose solutions

“…The transparent MC solutions at room temperature become turbid gels at high concentrations and elevated temperatures. This gelation behavior is almost the same as those reported thus far by other researchers 2, 3…”

Laser speckle analysis on correlation between gelation and phase separation in aqueous methyl cellulose solutions

“…The transparent MC solutions at room temperature become turbid gels at high concentrations and elevated temperatures. This gelation behavior is almost the same as those reported thus far by other researchers 2, 3…”

Formation of junction zones in thermoreversible methylcellulose gels

“…On the theoretical side, Tanaka and Ishida9 showed by lattice theoretical analysis that the competition between polymer–polymer direct hydrogen bonding and polymer–water hydrogen bonding leads to the coexistence of inverted gelation and phase separation at high temperatures. Our experimental phase diagrams1 qualitatively agree with the theoretically calculated ones. Therefore, it is suggested that the value of Δ h 0 = 25 kJ/mol contains two parts caused by hydrogen bonds and hydrophobic interactions.…”

“…Willcox et al6 reported that the value of a correlation length for poly(vinyl alcohol) gel measured by SAXS reflects the average crystalline radius of gyration, and the value falls somewhere in the range of 30–80 Å. Furthermore, the appearance of double peaks in our DSC curves has already been stated in our previous work 1. Kobayashi et al7 also suggested that the gelation of semidilute MC solutions proceeds in two stages with increasing temperatures above 20 °C.…”

Interplay of Phase Separation and Thermoreversible Gelation in Aqueous Methylcellulose Solutions

“…Consequently, assignment of the gel phase in Figure a was not based on rheological measurements at all. Takahashi et al also noted that molecular weights of 124, 357, and 783 kDa result in a shift of the sol–gel and phase separation boundaries to higher temperature and concentration with decreasing M . In contrast, we find that for 150 kDa ≤ M w ≤ 530 kDa the sol–gel phase transition does not depend on M and that there is no distinction between the sol–gel transition and phase separation.…”

Laser speckle analysis on correlation between gelation and phase separation in aqueous methyl cellulose solutions

“…The transparent MC solutions at room temperature become turbid gels at high concentrations and elevated temperatures. This gelation behavior is almost the same as those reported thus far by other researchers 2, 3…”

Formation of junction zones in thermoreversible methylcellulose gels

“…On the theoretical side, Tanaka and Ishida9 showed by lattice theoretical analysis that the competition between polymer–polymer direct hydrogen bonding and polymer–water hydrogen bonding leads to the coexistence of inverted gelation and phase separation at high temperatures. Our experimental phase diagrams1 qualitatively agree with the theoretically calculated ones. Therefore, it is suggested that the value of Δ h 0 = 25 kJ/mol contains two parts caused by hydrogen bonds and hydrophobic interactions.…”

“…Willcox et al6 reported that the value of a correlation length for poly(vinyl alcohol) gel measured by SAXS reflects the average crystalline radius of gyration, and the value falls somewhere in the range of 30–80 Å. Furthermore, the appearance of double peaks in our DSC curves has already been stated in our previous work 1. Kobayashi et al7 also suggested that the gelation of semidilute MC solutions proceeds in two stages with increasing temperatures above 20 °C.…”

Interplay of Phase Separation and Thermoreversible Gelation in Aqueous Methylcellulose Solutions

“…Consequently, assignment of the gel phase in Figure a was not based on rheological measurements at all. Takahashi et al also noted that molecular weights of 124, 357, and 783 kDa result in a shift of the sol–gel and phase separation boundaries to higher temperature and concentration with decreasing M . In contrast, we find that for 150 kDa ≤ M w ≤ 530 kDa the sol–gel phase transition does not depend on M and that there is no distinction between the sol–gel transition and phase separation.…”

Laser speckle analysis on correlation between gelation and phase separation in aqueous methyl cellulose solutions

“…The transparent MC solutions at room temperature become turbid gels at high concentrations and elevated temperatures. This gelation behavior is almost the same as those reported thus far by other researchers 2, 3…”

Formation of junction zones in thermoreversible methylcellulose gels

“…On the theoretical side, Tanaka and Ishida9 showed by lattice theoretical analysis that the competition between polymer–polymer direct hydrogen bonding and polymer–water hydrogen bonding leads to the coexistence of inverted gelation and phase separation at high temperatures. Our experimental phase diagrams1 qualitatively agree with the theoretically calculated ones. Therefore, it is suggested that the value of Δ h 0 = 25 kJ/mol contains two parts caused by hydrogen bonds and hydrophobic interactions.…”

“…Willcox et al6 reported that the value of a correlation length for poly(vinyl alcohol) gel measured by SAXS reflects the average crystalline radius of gyration, and the value falls somewhere in the range of 30–80 Å. Furthermore, the appearance of double peaks in our DSC curves has already been stated in our previous work 1. Kobayashi et al7 also suggested that the gelation of semidilute MC solutions proceeds in two stages with increasing temperatures above 20 °C.…”

Interplay of Phase Separation and Thermoreversible Gelation in Aqueous Methylcellulose Solutions

“…Consequently, assignment of the gel phase in Figure a was not based on rheological measurements at all. Takahashi et al also noted that molecular weights of 124, 357, and 783 kDa result in a shift of the sol–gel and phase separation boundaries to higher temperature and concentration with decreasing M . In contrast, we find that for 150 kDa ≤ M w ≤ 530 kDa the sol–gel phase transition does not depend on M and that there is no distinction between the sol–gel transition and phase separation.…”