Visualizing Interfacial Jamming Using an Aggregation-Induced Emission Molecular Reporter
Pei-Yang Gu1,2 ,+ , Feng Zhou1,+,Ganhua Xie2, + , Paul Y. Kim2, Yu Chai3, Qin Hu2,4,6, Shaowei Shi7, Qing-Feng Xu1, Feng Liu5, Jian-Mei Lu1,*（路建美）, and Thomas P. Russell2 ,6,7,8,*
1 College of Chemistry, Chemical Engineering and Materials Science
Collaborative Innovation Center of Suzhou Nano Science and Technology, Soochow University, Suzhou 215123 (China)
2 Materials Sciences Division, Lawrence Berkeley National Laboratory
1 Cyclotron Road, Berkeley, CA 94720 (USA)
3 Department of Physics, City University of Hong Kong,Kowloon (China)
4 School of Microelectronics,University of Science and Technology of China.Hefei, Anhui 230026 (China)
5 Department of Physics and Astronomy, Collaborative Innovation Center of IFSA (CICIFSA), Shanghai Jiaotong University,Shanghai 200240 (P. R. China)
6 Polymer Science and Engineering Department,University of Massachusetts,Amherst, MA 01003 (USA)
7 Beijing Advanced Innovation Center for Soft Matter Science and Engineering, Beijing University of Chemical Technology,Beijing 100029 (China)
8Advanced Institute for Materials Research (WPI-AIMR),Tohoku University,2-1-1 Katahira, Aoba, Sendai 980-8577 (Japan)
+ These authors contributed equally to this work.
Angew. Chem. Int. Ed.2021, 60, 8694--8699
With the interfacial jamming of nanoparticles (NPs), a load‐bearing network of NPs forms as the areal density of NPs increases, converting the assembly from a liquid‐like into a solid‐like assembly. Unlike vitrification, the lineal packing of the NPs in the network is denser, while the remaining NPs can remain in a liquid‐like state. It is a challenge to determine the point at which the assemblies jam, since both jamming and vitrification lead to a solid‐like behavior of the assemblies. Herein, we show a real‐time fluorescence imaging method to probe the evolution of the interfacial dynamics of NP surfactants at the water/oil interface using aggregation‐induced emission (AIE) as a reporter for the transition of the assemblies into the jammed state. The AIEgens show typical fluorescence behavior at densities at which they can move and rotate. However, when aggregation of these fluorophores occurs, the smaller intermolecular separation distance arrests rotation, and a significant enhancement in the fluorescence intensity occurs.