摘要
采用水热法,以聚乙烯亚胺(PEI)为表面改性剂,合成了水分散性较好的上转换纳米粒子(UC@PEI NPs)。考察了溶剂组成、反应时间、PEI分子量与加入量对UC@PEI NPs发光强度的影响,并进行了表征。结果显示:V(H2O)∶V(EG)=1∶1,PEI(Mw=10000)加入量为1.2 g,并于200℃反应8 h为最优合成条件。随后在UC@PEI NPs、聚N-异丙基丙烯酰胺(PNIPAM)存在下,丙烯酰胺、N,N’-亚甲基双丙烯酰胺发生自由基聚合,制备复合水凝胶,采用SEM、拉伸试验机、发光光谱仪进行形貌、机械强度和发光温度响应性的表征。结果表明:该互穿网络结构复合水凝胶反复脱水溶胀后,材料保持完好,平均脱水率和溶胀率为81.18%和61.38%;应力作用下的应变量达到251.10%,机械强度为22.92 kPa;在980 nm近红外光激发下,当温度从20℃升至48℃时,540 nm处(Er3+,4S3/2→4I15/2)的发光强度减少42.64%,而当温度下降,发光强度可逆回升。说明该复合水凝胶具有可逆的上转换发光温度响应性,材料稳定性和拉伸性良好,并且有一定的机械强度。
Water-dispersive upconversion nanoparticles(UC@PEI NPs)were synthesized by hydrothermal method using polyethyleneimine(PEI)as surface modification agent.The effects of solvent components,reaction time,relative molecular mass(Mw)of PEI and addition dosage of PEI on the luminescence intensity were investigated.The sample was characterized.The results showed that the optimal synthesis conditions were as follows:V(H2 O)∶V(EG)=1∶1,PEI(Mw=10000)dosage 1.2 g,reaction temperature 200℃,and reaction time 8 h.Subsequently,a composite hydrogel was prepared from acrylamide and N,N’-methylenebisacrylamide by free radical polymerization in the presence of UC@PEI NPs and poly(N-isopropylacrylamide)(PNIPAM).The morphology,mechanical strength and luminescent thermosensitive of composite hydrogel were characterized by SEM,tensile testing machine and luminescence spectrometer.It was found that the composite hydrogel with interpenetrating network structure still remained intact after repeated dehydration and swelling,and the average dehydration ratio and swelling ratio were 81.18%and 61.38%,respectively.The strain under stress was 251.10%,and the mechanical strength was 22.92 kPa.Under the excitation of 980 nm NIR laser,the luminescence intensity of composite hydrogel at 540 nm(Er3+,4 S3/2→4 I15/2)was decreased by 42.64%when the temperature rised from 20℃to 48℃.While the luminescence intensity could be reversibly recovered when the temperature dropped.The results indicated that the composite hydrogel had a reversible upconversion luminescent thermo-sensitive property,possessed good stability and tensile property,and exhibited a certain mechanical strength.
作者
张伟
廖正芳
阿尔普丁·艾尼娃尔
左芳
Zhang Wei;Liao Zhengfang;A Erpuding·Ai Niwaer;Zuo Fang(College of Chemistry and Environmental Protection Engineering,Southwest Minzu University,Chengdu 610041,Sichuan,China)
出处
《精细化工》
EI
CAS
CSCD
北大核心
2020年第2期270-277,共8页
Fine Chemicals
基金
西南民族大学研究生创新型科研项目(CX2018SZ127).
关键词
水热法
上转换纳米粒子
PNIPAM
发光温度响应性
水凝胶
功能材料
hydrothermal method
upconversion nanoparticles
PNIPAM
luminescent thermo-sensitive property
hydrogel
functional materials
作者简介
张伟(1994─),男,硕士生,E-mail:polymerzw@163.com;联系人:左芳(1980─),女,研究员,E-mail:polymerzf@swun.cn。
