Numerical simulation of coil–helix transition processes of gelatin
Numerical simulation of coil–helix transition processes of gelatin
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DOI：
10.1016/j.polymer.2009.02.039
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发表时间：
2009-04
期刊：
影响因子：
4.6
通讯作者：
Chen Xiliang;Yuxi Jia;Ligang Feng;Sheng Sun;L. An
中科院分区：
文献类型：
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作者：
Chen Xiliang;Yuxi Jia;Ligang Feng;Sheng Sun;L. An
明胶因其卷曲-螺旋转变而广泛应用于食品、制药和照相等行业，而其结构的不均匀性对其与工业应用密切相关的基本性质有很大影响。采用有限元方法分析了冷却诱导线圈-螺旋线转变过程中由于温度场的不均匀性和不稳定性而引起的明胶空间结构的不均匀性。用增量法计算了螺旋转化率和交联密度随时间和空间网格的变化。引入长度分布密度函数来描述两种三股螺旋的连续长度分布。结果表明，交联密度和三股螺旋长度分布与热历史有关。随着明胶初始浓度和对流换热系数的增大，空间结构的不均匀性更加明显。本工作有助于优化明胶的制备条件。
Gelatin is widely used in food, pharmaceutical, and photographic industries due to the coil–helix transition, whereas the structural inhomogeneity considerably affects its essential properties closely connecting with the industrial applications. The spatially structural inhomogeneity of the gelatin caused by the uneven and unstable temperature field is analyzed by the finite element method during the cooling-induced coil–helix transition process. The helix conversion and the crosslinking density as functions of time and spatial grid are calculated by the incremental method. A length distribution density function is introduced to describe the continuous length distributions of two kinds of triple helices. The results show that the crosslinking density and the length distribution of triple helices are dependent on the thermal histories. And the spatially structural inhomogeneity is more distinct when the initial gelatin concentration and the convective heat transfer coefficient increase. The present work is helpful for optimizing the fabrication conditions of gelatin.