摘要
以壳聚糖(CS)替代传统荧光增白剂中一种氨基化合物,经过三步缩合反应合成系列壳聚糖改性荧光增白剂(CS-FBs),用紫外光谱、荧光光谱、光致异构化及应用试验等手段研究它们在水和乙醇溶液中光物理化学性质及增白性能,以硫酸奎宁的0.5mol/L硫酸溶液为标准,测定各化合物的荧光量子产率;同时考察浓度和溶剂极性及化合物结构对荧光性能影响。结果表明此壳聚糖高分子型荧光增白剂与传统荧光增白剂VBL相比,可明显提高光的稳定性及荧光量子产率,降低光致异构现象,提高涂布增白效果和物理强度。同时发现随着溶剂极性增大,荧光量子产率增大,荧光波长红移;当浓度超过9×10-4g/mL时出现荧光浓度自猝灭;且三嗪环上取代基类型直接影响顺-反式异构体的比例,但对光吸收和荧光分配并无显著影响。
Replacing one of amino compounds of traditional fluorescent brighteners with chitosan,the fluorescent brighteners modified by chitosan（CS-FBs） were synthesized through three-step condensation reaction.The photophysical and photochemical characteristics and whitening properties in aqueous solutions and ethanol were studied by ultraviolet ray absorption spectra,fluorescence emission spectra,photoinduced isomerization phenomena and paper application test of CS-FBs.Fluorescence quantum yield are determined using quinine sulfate in 0.5mol/L H2SO4（ΦF=0.55）as fluorescence standard.The effect of concentration and polarity of solvents on fluorescence properties,as well as the ralationship of the structures and fluorescence properties were studied.The results show that,comparing with the traditional FBs,such as VBL,the light stability and fluorescence quantum yield of CS-FBs were greater,and photoinduced isomerization was lower,the whitening effect of coated paper and physical strength was enhanced.At the same time a red shift of fluorescence emmission wavelength and fluorescence quantum yield increaseing with the increase of solvent polarity.When the concenteation was over 9×10-4g/mL,the fluorescence was quenched.Meanwhile,the type of substituents in the triazine ring can affect directly the concentration of trans-and Cis-isomers,but not affect significantly absorption-fluorescence assignments.
出处
《功能材料》
EI
CAS
CSCD
北大核心
2011年第4期685-688,692,共5页
Journal of Functional Materials
基金
国家自然科学基金资助项目(5037302)
陕西省自然科学研究资助项目(2009JM2010)
陕西省教育厅科学研究计划资助项目(09JK801)
陕西省轻化工助剂重点实验室省部共建开放基金资助项目(ZK200801)
关键词
壳聚糖
改性
荧光增白剂
光学性能
光致异构化
chitosan（CS）
modified
fluorescent brighteners
optical properties
photoinduced isomerization
