摘要
目的 通过β-环糊精(β-CD)在聚氨酯膜表面进行分子自组装来增加聚氨酯表面的羟基数量,进而增强改性聚氨酯分子在高湿度环境下的电输出性能。方法 采用分子自主组装的方法获得改性聚氨酯膜。聚氨酯颗粒在N,N-二甲基甲酰胺中溶解并通过流延法成膜后,先后在γ-缩水甘油醚氧丙基三甲氧基硅烷/甲醇溶液和氨基环糊精溶液中浸泡、干燥,得到β-CD功能面。以改性的聚氨酯为摩擦纳米发电机(TENG)的电正性摩擦层,以聚四氟乙烯(PTFE)为电负性摩擦层,组装得到风驱动摩擦纳米发电机。结果 β-环糊精的改性增加了聚氨酯膜表面的羟基数量,使聚氨酯膜在高湿度环境中可以与水分子形成氢键,固定水分子一同参与摩擦起电,增加了聚氨酯基摩擦纳米发电机在高湿度环境中的电输出性能。当湿度从15%增加到95%后,改性聚氨酯基摩擦纳米发电机的短路电流增加了432%,且湿度越大,电输出越大。同时,改性聚氨酯基摩擦纳米发电机在喷洒水滴的情况下,也能点亮248个LED灯。结论 β-环糊精的改性可以显著提升聚氨酯基摩擦纳米发电机在高湿度环境下的电输出性能,且电输出随湿度的增加而增加,显示了出色的耐湿性,对扩展聚氨酯基摩擦纳米发电机的应用具有重要意义,尤其是在高湿度环境下。
Since the invention of the first triboelectric nanogenerator(TENG),more and more attention has been focused on this energy harvesting device due to its wide range of energy sources,low cost,and high reliability.There are many factors that affect the output performance of triboelectric nanogenerators,including the surface structure and composition of the friction pair material, frictional motion conditions, environmental factors, structure of the device and composition of the circuit. Especially for solid-solid triboelectric nanogenerators, ambient humidity has a significant impact on their output performance, which not only affects the energy harvesting efficiency and working reliability of triboelectric nanogenerators, but also greatly reduces their practical application range, especially in high humidity areas. Typically, ambient humidity accelerates the transfer, neutralization or dissipation of triboelectric charges on the friction surface, resulting in lower output of triboelectric nanogenerators. On the one hand, in a high-humidity environment, water molecules in the air are adsorbed on the surface of the friction pair to form a conductive water film, which can increase the conductivity of the friction interface and enable rapid transfer or neutralization of triboelectric charges. On the other hand, water molecules in the air accelerate the dissipation of charges on the friction surface during the migration process. Therefore, in previous reports, the output performance of solid-solid triboelectric nanogenerators generally decreases with increasing humidity, which greatly limits its practical application for energy harvesting in high-humidity environments. To solve this problem, β-cyclodextrin (β-CD) was introduced on the surface of thermoplastic polyurethane (TPU) film by molecular self-assembly to increase the number of hydroxyl groups to enhance the contact electrification (CE) performance of modified polyurethane molecules in a high-humidity environment. β-Cyclodextrin was a hydroxyl-rich bio-based macromolecule, which could spontaneously form hydrogen bonds with water molecules in the environment under high humidity, thereby immobilizing the water molecules on the surface of modified polyurethane. The bound water fixed on the surface of the polyurethane participated in triboelectric charging with the polyurethane as a whole. Since water was very triboelectrically positive, and polyurethane was also a triboelectrically positive material, the triboelectrically positive superposition effect of the two ultimately led to an increase in the electrical output of the modified polyurethane-based TENG. In addition, the surface of the modified polyurethane film was patterned, which not only greatly increased the contact area between polyurethane and PTFE during triboelectric electrification, but also improved the separation speed of the two, which further improved the electrical output performance. When the humidity increased from 15% to 95%, the short-circuit current of the TPU-based TENG increased by 432%. The electrical output of the modified TPU-based TENG was increased by 409% compared with the pure TPU-based TENG in a high-humidity environment. This TENG could light up 248 LEDs in the state of continuous spraying of water droplets, showing excellent moisture resistance. Besides moisture resistance, the improved electrical output of the modified TPU-based TENG also benefited from the introduction of β-cyclodextrin to increase the dielectric properties of the TPU film, which enabled more positive charges and storage in the triboelectric process. Due to the high performance of the modified TPU-based TENG under high humidity, this smart self-powered system can efficiently harvest wind energy in the marine environment and store energy by converting wind energy to power small electronic devices.
作者
贾贞贞
钟先锦
吴丹
方丽波
沈慧
安燕
戴若萌
无
JIA Zhen-zhen;ZHONG Xian-jin;WU Dan;FANG Li-bo;SHEN Hui;AN Yan;DAI Ruo-meng(College of Bioengineering,Hefei Technology College,Anhui Chaohu 238000,China;Guizhou University,Guiyang 550025,China)
出处
《表面技术》
EI
CAS
CSCD
北大核心
2023年第11期377-385,共9页
Surface Technology
基金
安徽高校自然科学基金(KJ2021A1388,KJ2020A0980)
合肥职业技术学院自然科学基金(2021KJB13,2021KJB05,2022Akjcx02)。
关键词
Β-环糊精
分子自组装
摩擦纳米发电机
耐湿性
氢键
β-cyclodextrin
molecular self-assembly
triboelectric nanogenerator
humidity resistance
hydrogen bonding
