Plant-Inspired Multifunctional Fluorescent Hydrogel: A Highly Stretchable and Recoverable Self-Healing Platform with Water-Controlled Adhesiveness for Highly Effective Antibacterial Application and Data Encryption–Decryption

Abstract

In recent years, hydrogels as an attractive class of intelligent soft materials have been applied in various advanced fields, including electronic materials, wearable devices, and wound dressing materials. However, it still remains a critical challenge to integrate information encryption transmission capability, antibacterial activity, high mechanical performance, adhesiveness, and self-healable ability into one material and achieve the synergistic characteristics through a simple method. In our study, a facile strategy of a plant-inspired hydrogel was proposed, which provides a novel initiator-free photo-cross-linked hydrogel system by simply mixing the coumarin derivative Pho-CA and the monomer in water, and then obtaining the hydrogel Gel-C-Am under the irradiation of UV light without adding any other cross-linking agents and initiators, and this process is very similar to the growth process of plants in nature. This novel hydrogel presents desirable mechanical properties (including twist, stretchability, and recoverability), which exhibits elongation of approximately 1600%. More interestingly, Gel-C-Am hydrogel displays reversible adhesiveness to various substrates (such as glass, paper, leaves, and rubber), and its adhesion properties can be regulated by water: the viscosity disappears when its surface becomes wet, and the viscosity will recover after the water evaporates. In addition, the developed hydrogel has certain self-healable ability. Two pieces of the Gel-C-Am hydrogel can combine together and reshape into one piece in water, and the fused hydrogel has uniform and interconnected pores under SEM. Based on the characteristic of Pho-CA whose fluorescence get recovery after UV irradiation, the hydrogel can be used in the field of encryption and decryption. Also, the resulting Gel-C-Am hydrogel shows an effective antibacterial activity and can potentially be addressed as antibacterial coatings. Taken together, the formation of the novel fluorescent hydrogel system is just like the growth of a plant in the presence of water and light, Pho-CA and the monomer will form a highly stretchable and recoverable self-healing hydrogel with water-controlled adhesiveness. The developed Gel-C-Am hydrogel shows favorable attributes and is suitable for applications in antibacterial polymeric coatings and information encryption transmission.

Multi-Functional Hydrogels Simultaneously Featuring Strong Fluorescence, Ultralong Phosphorescence, and Excellent Self-Healing Properties and Their Use for Advanced Anti-counterfeiting

“…Because of the hydrogen bonding of −OH and tetra-functional borate ions, the as-prepared hydrogels possess rapid self-healing functionality. 25 Notably, the blue emission under UV light and green-colored afterglow under UV off can be observed at both the damaged and other positions, indicating that the hydrogels are able to maintain optical properties after the healing process. Figure 4f shows that the optical images of the control group and the hydrogels at different self-healing stages demonstrate that the cracks of the hydrogels could rapidly disappear during the 60 s healing process.…”

“…The weak hydrogen bonding in the cross-linked network is easily broken through mechanical deformation. Because of the hydrogen bonding of −OH and tetra-functional borate ions, the as-prepared hydrogels possess rapid self-healing functionality . Notably, the blue emission under UV light and green-colored afterglow under UV off can be observed at both the damaged and other positions, indicating that the hydrogels are able to maintain optical properties after the healing process.…”

Mimicking Color-Changing Organisms to Enable the Multicolors and Multifunctions of Smart Fluorescent Polymeric Hydrogels

“…Consequently, the on-demand encryption of multicolor fluorescent patterns was realized with increasing irradiation time, significantly raising the difficulty of data decryption. Along this line, a number of smart FPHs with diverse responsiveness and programmable fluorescence changes have been designed for multistage information encryption, greatly enriching the potential tool box against data forging. ,− …”

Based on SM - 9 Cloud Edge System Information Security Transmission

“…Then the original plaintext data is divided into 128 bit blocks, and processed. Premnath [2] uses NTRU to implement authentication and data integrity protection within the system and compares NTRU execution time with ECC and RSA on the ARMV6 platform [4]. The results show that the execution speed is 2 to 2.5 times faster than the latter.…”