Isothermal Crystallization Kinetics of Sodium Dodecyl Sulfate-Water Micellar Solutions
Isothermal Crystallization Kinetics of Sodium Dodecyl Sulfate-Water Micellar Solutions
复制标题
十二烷基硫酸钠-水胶束溶液的等温结晶动力学
DOI：
10.1021/acs.cgd.6b00353
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发表时间：
2016
影响因子：
3.8
通讯作者：
Miller R
中科院分区：
文献类型：
--
作者：
Miller R
采用反射光学显微镜（OM）、差示扫描量热法（DSC）和衰减全反射傅里叶变换红外光谱（ATR-FTIR）研究了十二烷基硫酸钠（SDS）胶束水溶液在等温条件下的结晶机理和动力学。成核和生长速率通过OM和DSC在20至−6 °C的温度范围内对20% SDS-H2O以及10和30% SDS-H2O在6、2和−2 °C的代表性温度下进行估计。温度的降低增加了成核和生长速率，并通过OM和ATR-FTIR定量了两个过程对形貌的综合影响。针状物，对应于半水合物多晶型物，在≤ −2 °C时成为主要晶型，而片状物，一水合物，在较高温度下占主导地位。在高于8 °C时，仅当从在较低温度下产生的晶体接种时才观察到结晶。我们的研究结果提供了定量和形态学的洞察无处不在的胶束SDS溶液的结晶和其相稳定性低于室温。
The crystallization mechanisms and kinetics of micellar sodium dodecyl sulfate (SDS) solutions in water, under isothermal conditions, were investigated experimentally by a combination of reflection optical microscopy (OM), differential scanning calorimetry (DSC), and attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR). The rates of nucleation and growth were estimated from OM and DSC across temperatures ranging from 20 to −6 °C for 20% SDS-H2O, as well as for 10 and 30% SDS-H2O at representative temperatures of 6, 2, and −2 °C. A decrease in temperature increased both nucleation and growth rates, and the combined effect of the two processes on the morphology was quantified via both OM and ATR-FTIR. Needles, corresponding to the hemihydrate polymorph, become the dominant crystal form at ≤ −2 °C, while platelets, the monohydrate, predominate at higher temperatures. Above 8 °C, crystallization was only observed if seeded from crystals generated at lower temperatures. Our results provide quantitative and morphological insight into the crystallization of ubiquitous micellar SDS solutions and its phase stability below room temperature.