本文選題：再生纖維素 + 太赫茲光譜　； 參考：《光譜學(xué)與光譜分析》2017年03期

【摘要】：采用低溫溶解法制備了再生纖維素膜,運(yùn)用掃描電子顯微鏡、傅里葉紅外光譜儀和X射線衍射儀對(duì)所制薄膜進(jìn)行形貌和晶型表征。在此基礎(chǔ)上,結(jié)合太赫茲時(shí)域光譜和傅里葉變換紅外光譜技術(shù),測(cè)量了再生纖維素膜的太赫茲光譜。據(jù)此,詳細(xì)指認(rèn)了再生纖維素在太赫茲波段的特征峰,指出再生纖維素的太赫茲透過率隨波數(shù)的減少而增大的現(xiàn)象是由其無定形部分所導(dǎo)致。通過比較再生纖維素和脫脂棉在100～700cm～(-1)的光譜特性,發(fā)現(xiàn)兩者具有相似的峰形,但再生纖維素在此波段的特征峰相對(duì)于脫脂棉特征峰發(fā)生了不同程度的藍(lán)移。據(jù)此,提出了鑒別纖維素Ⅱ和纖維素Ⅰ_β同質(zhì)異晶體的一種新方法。重要的是,還采用CASTEP對(duì)纖維素Ⅱ晶體進(jìn)行結(jié)構(gòu)優(yōu)化及光譜的理論研究,并對(duì)再生纖維素的太赫茲特征峰進(jìn)行了系統(tǒng)的歸屬。理論計(jì)算結(jié)果表明,再生纖維素在42和54 cm～(-1)處的太赫茲特征峰分別是由平移振動(dòng)和轉(zhuǎn)動(dòng)的晶格振動(dòng)模式引起,而位于68～238 cm～(-1)間的太赫茲特征峰則與—CH_2OH基團(tuán)的扭絞振動(dòng)以及C—H及O—H的變形振動(dòng)相關(guān)。此外,351～583 cm～(-1)范圍內(nèi)的吸收峰與C—O—C及吡喃環(huán)的骨架振動(dòng)相關(guān),而611和670 cm～(-1)兩處的吸收峰則主要源于O—H的面外彎曲振動(dòng)。結(jié)果不僅揭示了再生纖維素的物質(zhì)結(jié)構(gòu)與太赫茲光譜間的聯(lián)系,也為理論上研究部分結(jié)晶的聚合物及生物有機(jī)大分子等的太赫茲響應(yīng)的物理原理提供了參考。
[Abstract]:The regenerated cellulose films were prepared by low temperature dissolution method. The morphology and crystal form of the films were characterized by scanning electron microscope, Fourier transform infrared spectroscopy and X-ray diffraction. On this basis, the terahertz spectra of regenerated cellulose membranes were measured by combining the terahertz time domain spectroscopy and Fourier transform infrared spectroscopy. Based on this, the characteristic peaks of regenerated cellulose in terahertz band are identified in detail. It is pointed out that the phenomenon that the terahertz transmittance of regenerated cellulose increases with the decrease of wave number is caused by its amorphous part. By comparing the spectral characteristics of regenerated cellulose and degreased cotton at 100 ~ 700 cm ~ (-1), it was found that they had similar peaks, but the characteristic peaks of regenerated cellulose in this band were blue shifted to different degrees compared with the characteristic peaks of degreased cotton. Accordingly, a new method for identifying homogeneous heterocrystals of cellulose 鈪，

本文編號(hào)：2104283