Lim J J, Shamos M H
Biophys J. 1971 Aug;11(8):648-63. doi: 10.1016/S0006-3495(71)86244-6.
The dielectric constant of natural tendon in the frequency range of 200 Hz to 100 kHz has been determined as a function of temperature (300-450 degrees K) for water concentrations ranging from about 6 to 16% by weight. The results compare well with the approach taken by Haggis and his coworkers. Based on the assumption that at low concentration of water the probability of water-water bonding is small and hence may be disregarded, a structure for water in the collagen matrix is proposed in which the water is either bonded in one of four possible states to the polar groups of the polypeptide chains, or is unbound. In determining the distribution of the water among these states an approach similar to that of Haggis and his co-workers, in conjunction with the order-disorder theory of Bragg and Williams, is used. The number of water molecules per unit volume is then determined experimentally by relating it to weight loss as a function of temperature, as determined by thermogravimetric analysis. The dispersion which is normally found in dipolar substances has not been found for tendon. A maximum in the value of the dielectric constant is observed to occur between 25 and 80 degrees C, the temperature depending upon the heating rate.
已测定了天然肌腱在200赫兹至100千赫兹频率范围内，作为温度（300 - 450开尔文）的函数，对于重量百分比约为6%至16%的水浓度的介电常数。结果与哈吉斯及其同事所采用的方法吻合良好。基于低水浓度时水 - 水键合概率小因而可忽略不计的假设，提出了胶原基质中水的一种结构，其中水要么以四种可能状态之一与多肽链的极性基团键合，要么未键合。在确定水在这些状态间的分布时，采用了一种类似于哈吉斯及其同事的方法，并结合布拉格和威廉姆斯的有序 - 无序理论。然后通过将单位体积内水分子数与热重分析所确定的作为温度函数的重量损失相关联，通过实验来确定它。在肌腱中未发现通常在偶极物质中出现的色散现象。观察到介电常数值在25至80摄氏度之间出现最大值，该温度取决于加热速率。
