可光致固液转变偶氮苯染料的合成及其光控可逆黏合性能

Synthesis of photo-induced solid-liquid transition azobenzene dye and its light-controlled reversible adhesive property

光控可逆胶黏剂在特定波长的光照射下可以改变其黏接性质,实现高效的黏合与分离,并可多次重复利用。试验设计合成了一种含单个偶氮苯单元的小分子化合物D-Azo,探究了其光致固液转化及光控可逆黏合性能。紫外光照射前后的紫外-可见吸收光谱、氢核磁共振谱(1H NMR)及示差热量扫描(DSC)表明,在紫外光的作用下,D-Azo分子发生了异构转变,在光诱导下染料由固态快速转化为液态,且具有良好的循环稳定性,能够在多个光照周期中保持稳定的光响应性能。将D-Azo用于光控可逆黏合,D-Azo黏接的PMMA板承重达30~35 kg,黏附强度为0.80~0.93 MPa。D-Azo分子具有明显的光致固液转化特性,紫外光照射可以使其脱黏合,表明作为胶黏剂的可逆性和重复使用性能。该材料可望在纺织复合材料黏合领域以及可穿戴黏合材料等领域获得应用。

Light-controlled reversible adhesives can change their adhesive properties under the illumination of specific wavelength of light,achieving efficient bonding and separation,and can be reused multiple times.In this study,a small molecule compound,D-Azo,containing a single azobenzene unit was designed and synthe⁃sized to explore its photo-induced solid-liquid transition and light-controlled reversible adhesive property.UVVis absorption spectroscopy,hydrogen nuclear magnetic resonance(1H NMR),and differential scanning calorim⁃etry(DSC)of D-Azo before and after the UV irradiation indicate that under the effect of UV light,D-Azo mole⁃cule undergoes a transition from a trans-isomer-rich state to a cis-isomer-rich state,exhibiting good cyclic stability and maintaining the stable photoresponsive property over multiple light exposure cycles.This photo-in⁃duced isomerization property enables D-Azo molecule to demonstrate the significant photo-induced solid-liq⁃uid transformation characteristic.Utilizing this property,D-Azo was applied as a light-controlled reversible ad⁃hesive.The D-Azo adhesive on PMMA boards supported a load of 30-35 kg,with an adhesive strength of 0.80-0.93 Mpa.UV irradiation significantly reduced its adhesive strength,confirming its reversibility and reus⁃ability as an adhesive.This material is expected to be applied in the textile composite bonding and wearable bonding fields.