title: In situ observation of heat- and pressure-induced gelation of methylcellulose by fluorescence measurement.
abstract: In situ observation of heat- and pressure-induced gelation of methylcellulose (MC) aqueous solution has been studied by using dynamic viscoelastic and fluorescence measurements. The storage modulus G' decreased gradually first on heating, and then leveled off in the temperature range from 25 °C to 75 °C. Methylcellulose solutions were subjected to pressures up to 450 MPa by using a high pressure cell. It was indicated that the microviscosity showed a dramatic change in the vicinity of the phase transition point. The T vs. P phase diagram of methylcellulose aqueous solution was constructed, and it indicated that the melting point was an increasing function of pressure. In situ microscopic observation of pressure-induced gelation of methylcellulose aqueous solution was also performed with a microscope, and it could be seen that gel phase of the sample disappeared and sol formed gradually. Pressure-released study by fluorescence measurement also showed that the phase transition of MC solution was reversible.
authors.affiliation: Graduate School of Human Life Science, Osaka City University, Sugimoto, Sumiyoshiku, Osaka 558-8585, Japan; The High Pressure Research Center of Science and Technology, Zhengzhou University of Light Industry, Zhengzhou 450002, China.
authors.forename: L
authors.initials: L
authors.lastname: Su
authors.affiliation: Graduate School of Human Life Science, Osaka City University, Sugimoto, Sumiyoshiku, Osaka 558-8585, Japan; The High Pressure Research Center of Science and Technology, Zhengzhou University of Light Industry, Zhengzhou 450002, China.
authors.forename: Z
authors.initials: Z
authors.lastname: Wang
authors.affiliation: Graduate School of Human Life Science, Osaka City University, Sugimoto, Sumiyoshiku, Osaka 558-8585, Japan; The High Pressure Research Center of Science and Technology, Zhengzhou University of Light Industry, Zhengzhou 450002, China.
authors.forename: K
authors.initials: K
authors.lastname: Yang
authors.affiliation: Graduate School of Engineering, Osaka City University, Sugimoto, Sumiyoshiku, Osaka 558-8585, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Minamikawa
authors.affiliation: Graduate School of Engineering, Osaka City University, Sugimoto, Sumiyoshiku, Osaka 558-8585, Japan.
authors.forename: N
authors.initials: N
authors.lastname: Kometani
authors.affiliation: Graduate School of Human Life Science, Osaka City University, Sugimoto, Sumiyoshiku, Osaka 558-8585, Japan; Glyn O.Phillips Hydrocolloids Research Centre, School of Food and Pharmaceutical Engineering, Faculty of Light Industry, Hubei University of Technology, Wuchang, Wuhan 430068, China. Electronic address: katsuyoshi.nishinari@gmail.com.
authors.forename: K
authors.initials: K
authors.lastname: Nishinari
mesh_terms: D005470:Fluorometry; D005782:Gels / Q000737:chemistry*; D006358:Hot Temperature; D008747:Methylcellulose / Q000737:chemistry*; D058105:Polymerization; D011312:Pressure; D012212:Rheology; D013816:Thermodynamics
chemical_list: D005782:Gels; D008747:Methylcellulose
keywords: Fluorescence; Gelation; Methylcellulose