光谱学与光谱分析
光譜學與光譜分析
광보학여광보분석
SPECTROSCOPY AND SPECTRAL ANALYSIS
2010年
5期
1252-1256
,共5页
正二十六烷%拉曼光谱%旋转相%相变
正二十六烷%拉曼光譜%鏇轉相%相變
정이십륙완%랍만광보%선전상%상변
n-hexacosane%Raman spectroscopy%Rotator phase%Phase transition
利用激光拉曼光谱研究了二十六烷的凝结相变过程.在冷却过程中,二十六烷经历了从液相→旋转相→固态单斜品相的相变过程.主要研究了烷烃分子碳链上CH2弯曲振动、CH2剪式振动、C-C伸展振动和CH3平面摇摆等振动模式的变化过程,包括这些模的频率、半宽和强度变化等,研究在相变过程中不同振动模式的的演变顺序和过程,反映各种振动模式与分子结构的相关性,并了解反式构象和歪曲构象在相变过程中的变化,从而更深入的理解烷烃等非晶体物质的相变过程.此外,通过分析800~1 500 cm-1波段各个拉曼波峰在降温过程中的变化过程,得到了二十六烷的旋转相的温度区间,证明可以利用拉曼光谱来观察烷烃相变过程中出现的旋转相.
利用激光拉曼光譜研究瞭二十六烷的凝結相變過程.在冷卻過程中,二十六烷經歷瞭從液相→鏇轉相→固態單斜品相的相變過程.主要研究瞭烷烴分子碳鏈上CH2彎麯振動、CH2剪式振動、C-C伸展振動和CH3平麵搖襬等振動模式的變化過程,包括這些模的頻率、半寬和彊度變化等,研究在相變過程中不同振動模式的的縯變順序和過程,反映各種振動模式與分子結構的相關性,併瞭解反式構象和歪麯構象在相變過程中的變化,從而更深入的理解烷烴等非晶體物質的相變過程.此外,通過分析800~1 500 cm-1波段各箇拉曼波峰在降溫過程中的變化過程,得到瞭二十六烷的鏇轉相的溫度區間,證明可以利用拉曼光譜來觀察烷烴相變過程中齣現的鏇轉相.
이용격광랍만광보연구료이십륙완적응결상변과정.재냉각과정중,이십륙완경력료종액상→선전상→고태단사품상적상변과정.주요연구료완경분자탄련상CH2만곡진동、CH2전식진동、C-C신전진동화CH3평면요파등진동모식적변화과정,포괄저사모적빈솔、반관화강도변화등,연구재상변과정중불동진동모식적적연변순서화과정,반영각충진동모식여분자결구적상관성,병료해반식구상화왜곡구상재상변과정중적변화,종이경심입적리해완경등비정체물질적상변과정.차외,통과분석800~1 500 cm-1파단각개랍만파봉재강온과정중적변화과정,득도료이십륙완적선전상적온도구간,증명가이이용랍만광보래관찰완경상변과정중출현적선전상.
Raman spectroscopy was used to investigate the phase transition of n-hexacosane for real-time cooling run.In the cooling process,the n-hexacosane experienced the melt phase→rotator phase→monoelinic crystal phase transition.The changes in band intensity and frequency in the CH2 bending,CH2 twisting,skeletal C-C stretching,and CH3 rocking regions were mainly analyzed in order to know the changing sequence and process of these vibrational inodes,and to reflect the relationship between these vibrational modes and molecular structure.Besides,the changes in band intensity and frequency revealed both transitions,particularly when using band components related to gauche bonds.Our research shows that Raman spectroscopy is an effective tool to monitor the phase transition of n-alkanes or even long-chain polymers.In addition,by analyzing the Raman peaks in 800-1 500 cm-1 in the cooling process of n-hexacosane.the temperature range of rotator phase was obtained,proving that Raman spectroscopy can be used to observe the rotator phase occurring during the phase transition of paraffin.