物理化学学报
物理化學學報
물이화학학보
ACTA PHYSICO-CHIMICA SINICA
2001年
5期
400-405
,共6页
李淑芹%胡新根%林瑞森%方文军%桑文强%刘庆旺
李淑芹%鬍新根%林瑞森%方文軍%桑文彊%劉慶旺
리숙근%호신근%림서삼%방문군%상문강%류경왕
甘氨酸%多元醇-水混合溶剂%极限偏摩尔体积%结构相互作用
甘氨痠%多元醇-水混閤溶劑%極限偏摩爾體積%結構相互作用
감안산%다원순-수혼합용제%겁한편마이체적%결구상호작용
利用精密数字密度计测定了甘氨酸分别在不同组成的乙二醇-水和丙三醇-水混合溶剂中的密度,计算了甘氨酸的表观摩尔体积、极限偏摩尔体积和理论水化数 .根据结构水合作用模型讨论了迁移偏摩尔体积的变化规律,并与乙醇-水体系作了比较 . 结果表明,甘氨酸分子在醇-水混合溶剂中增体积效应的大小与醇分子所含 OH基数目的多少有关,但最直接也是最重要的影响因素是其水合壳层的结构形态 . 乙醇-水体系中的增体积效应特别显著与该溶剂结构变化上的微观不均匀性和不连续性有关 .
利用精密數字密度計測定瞭甘氨痠分彆在不同組成的乙二醇-水和丙三醇-水混閤溶劑中的密度,計算瞭甘氨痠的錶觀摩爾體積、極限偏摩爾體積和理論水化數 .根據結構水閤作用模型討論瞭遷移偏摩爾體積的變化規律,併與乙醇-水體繫作瞭比較 . 結果錶明,甘氨痠分子在醇-水混閤溶劑中增體積效應的大小與醇分子所含 OH基數目的多少有關,但最直接也是最重要的影響因素是其水閤殼層的結構形態 . 乙醇-水體繫中的增體積效應特彆顯著與該溶劑結構變化上的微觀不均勻性和不連續性有關 .
이용정밀수자밀도계측정료감안산분별재불동조성적을이순-수화병삼순-수혼합용제중적밀도,계산료감안산적표관마이체적、겁한편마이체적화이론수화수 .근거결구수합작용모형토론료천이편마이체적적변화규률,병여을순-수체계작료비교 . 결과표명,감안산분자재순-수혼합용제중증체적효응적대소여순분자소함 OH기수목적다소유관,단최직접야시최중요적영향인소시기수합각층적결구형태 . 을순-수체계중적증체적효응특별현저여해용제결구변화상적미관불균균성화불련속성유관 .
Densities have been determined for ternary aqueous solutions containing glycine, ethylene glycol or glycerol(cosolvent), with mass fractions of the polyols in cosolvent-water mixtures ranging from 0 to 0.50. The apparent molar volumes, the limiting partial molar volumes and hydration numbers of glycine zwitterion have been calculated. The transfer volumes from water to polyol-water mixtures have been obtained and discussed in terms of the structural hydration interaction model. The results obtained have been compared with that in ethanol-water mixtures. It is concluded that the magnitude of enhancement effect on volume is somewhat related to the number of OH groups on alcohol molecules. However, the most important factor that influences volumes is the structural shapes of hydration shells of alcohol molecules. The unusual enhancement effect on volume in ethanol-water mixtures is considered to be related to the fact that the micro-structure of the mixtures is heterogeneous and discontinuous.