光谱学与光谱分析
光譜學與光譜分析
광보학여광보분석
SPECTROSCOPY AND SPECTRAL ANALYSIS
2014年
9期
2320-2326
,共7页
罗伟昂%程玲%戴李宗%陈旭东%麦堪成%陈钰杰%廖正福
囉偉昂%程玲%戴李宗%陳旭東%麥堪成%陳鈺傑%廖正福
라위앙%정령%대리종%진욱동%맥감성%진옥걸%료정복
同步扫描光谱%热动力学%结晶动力学%聚合物
同步掃描光譜%熱動力學%結晶動力學%聚閤物
동보소묘광보%열동역학%결정동역학%취합물
Synchronous scanning spectrum%Thermodynamic%Crystallization kinetics%Polymer
固体表面反射光与其折射指数之间存在余弦函数关系,而折射指数的均方起伏又和固体表面的密度和浓度起伏有关。因此从反射光的变化可以反映材料内部结构的一些变化。基于此理论指导,本文利用同步扫描光谱(SSS )方法,即荧光光谱仪的同步扫描模式进行反射光的检测,成功地监测了聚己内酯(PCL )薄膜在铜片上的熔融和非等温结晶过程。PCL薄膜的SSS谱图出现了两个明显的荧光光谱仪的光源峰(467和473 nm ),利用这两个峰的信息可以表征聚合物的熔融和结晶过程中分子链结构的变化。采用SSS方法表征分析得到了PCL的热动力学和结晶动力学参数,其结晶Avrami exponent n为2.8~3.2,平均值为3.1,表明PCL的非等温结晶遵循异相成核、三维球晶生长机理。这些与差示扫描量热仪(DSC)得到的参数一致。研究结果表明SSS方法是一种简单、有效的原位测试聚合物熔融和结晶动态过程的方法。此外,SSS方法是一种基于荧光光谱仪的具有普适性的光谱方法,对发光和不发光固态聚合物均可以检测研究。
固體錶麵反射光與其摺射指數之間存在餘絃函數關繫,而摺射指數的均方起伏又和固體錶麵的密度和濃度起伏有關。因此從反射光的變化可以反映材料內部結構的一些變化。基于此理論指導,本文利用同步掃描光譜(SSS )方法,即熒光光譜儀的同步掃描模式進行反射光的檢測,成功地鑑測瞭聚己內酯(PCL )薄膜在銅片上的鎔融和非等溫結晶過程。PCL薄膜的SSS譜圖齣現瞭兩箇明顯的熒光光譜儀的光源峰(467和473 nm ),利用這兩箇峰的信息可以錶徵聚閤物的鎔融和結晶過程中分子鏈結構的變化。採用SSS方法錶徵分析得到瞭PCL的熱動力學和結晶動力學參數,其結晶Avrami exponent n為2.8~3.2,平均值為3.1,錶明PCL的非等溫結晶遵循異相成覈、三維毬晶生長機理。這些與差示掃描量熱儀(DSC)得到的參數一緻。研究結果錶明SSS方法是一種簡單、有效的原位測試聚閤物鎔融和結晶動態過程的方法。此外,SSS方法是一種基于熒光光譜儀的具有普適性的光譜方法,對髮光和不髮光固態聚閤物均可以檢測研究。
고체표면반사광여기절사지수지간존재여현함수관계,이절사지수적균방기복우화고체표면적밀도화농도기복유관。인차종반사광적변화가이반영재료내부결구적일사변화。기우차이론지도,본문이용동보소묘광보(SSS )방법,즉형광광보의적동보소묘모식진행반사광적검측,성공지감측료취기내지(PCL )박막재동편상적용융화비등온결정과정。PCL박막적SSS보도출현료량개명현적형광광보의적광원봉(467화473 nm ),이용저량개봉적신식가이표정취합물적용융화결정과정중분자련결구적변화。채용SSS방법표정분석득도료PCL적열동역학화결정동역학삼수,기결정Avrami exponent n위2.8~3.2,평균치위3.1,표명PCL적비등온결정준순이상성핵、삼유구정생장궤리。저사여차시소묘량열의(DSC)득도적삼수일치。연구결과표명SSS방법시일충간단、유효적원위측시취합물용융화결정동태과정적방법。차외,SSS방법시일충기우형광광보의적구유보괄성적광보방법,대발광화불발광고태취합물균가이검측연구。
There is a cosine function between the reflected light intensity of a solid surface and its refractive in-dex .And the mean squared fluctuation of refractive index is related to fluctuation of density and concentration . So some internal structures changes of materials can be reflected by changes in reflected light .Based on this theory ,the synchronous scanning spectrum (SSS) technique was successfully applied to monitor melting and nonisothermal melt-crystallization of poly (ε-caprolactone) (PCL ) film on a copper substrate .SSS can be im-plemented on a spectrofluorimeter by simultaneously scanning the excitation and emission monochromators (i .e .Δλ=λex -λem =0 nm) .In SSS of PCL films ,two dominant peaks correlated to the light source spectrum of the spectrofluorimeter (at 467 and 473 nm) were used to characterize the macromolecular structure evolution during the melting and nonisothermal melt-crystallization processes .Detailed thermodynamic and crystalliza-tion kinetics parameters obtained by SSS method .The Avrami exponent n obtained by SSS method is in the range of 2.8~3.2 with an average of 3.13 ,illustrating a heterogeneous nucleation process followed by a three-dimensional spherulitic crystal growth mechanism .The crystallization activation energy is -158.2 kJ · mol-1 . These results are in agreement with values determined from differential scanning calorimetry (DSC) method .It indicates that SSS technique is a simple ,effective in situ method for measuring the dynamic melting and crys-tallization process of polymers .Moreover ,the SSS method is a universal spectroscopic technique based on a spectrofluorimeter for monitoring both luminescent and non-luminous solid polymers .