School of Sciences, Wuhan University of Technology, Wuhan, Hubei 430070, China; Center for High Pressure Science and Technology Research, Zhengzhou University of Light Industry, Zhengzhou 450002, China.
Center for High Pressure Science and Technology Research, Zhengzhou University of Light Industry, Zhengzhou 450002, China.
Int J Biol Macromol. 2018 Jun;112:803-808. doi: 10.1016/j.ijbiomac.2018.02.020. Epub 2018 Feb 6.
Sol-gel transition behavior of agarose aqueous solution was investigated by using rheology and fluorescence measurement. On heating, the storage modulus G' decreased gradually, then deviated abruptly at the temperature of about 65°C, and finally decreased slowly again. For fluorescence measurement, the phase transition point kept almost at the temperature of 65°C, which was consistent with that in rheology measurement. Upon compression, it was indicated that the fluorescence lifetime for the probe in the agarose aqueous solution showed a dramatic change in the vicinity of the phase transition point. T vs. P phase diagram of agarose aqueous solution was constructed, which showed that the melting point was an increasing function of pressure. Based on the phase diagram, the agarose gels were prepared by cooling under atmospheric pressure and the pressure of 300MPa, respectively. From the result of the recovered samples studied by optical rheometry, it was found that agarose gel prepared under high pressure had a higher elasticity and lower viscosity index, compared with that under atmospheric pressure. It could be speculated that such kinds of properties might be attributed to the smaller pore size during gelation under high pressure.
琼脂糖水溶液的溶胶-凝胶转变行为通过流变学和荧光测量进行了研究。在加热过程中，储能模量 G'逐渐降低，然后在约 65°C 的温度下突然偏离，最后再次缓慢降低。对于荧光测量，相变点几乎保持在 65°C 的温度，这与流变学测量中的温度一致。在压缩过程中，表明探针在琼脂糖水溶液中的荧光寿命在相变点附近发生了显著变化。构建了琼脂糖水溶液的 T 与 P 相图，表明熔点是压力的增函数。基于相图，分别通过在大气压力和 300MPa 下冷却来制备琼脂糖凝胶。从通过光学流变仪研究的回收样品的结果发现，与在大气压力下相比，在高压下制备的琼脂糖凝胶具有更高的弹性和更低的粘度指数。可以推测，这种性质可能归因于高压下凝胶化过程中的孔径更小。
