Water, as an omnipresent substance, plays a vital role in many aspects of our lives, ranging from sustaining living organisms to driving technological advancements. The exploration of organic reactions in water or the utilization of natural water as a reactant has attracted significant attention due to their advantages, including unique reaction performance, environmental friendliness, and reduction of harmful wastes. In this talk, the recent research progress on new polymerization approaches involving water and monomers containing triple-bond functionalities such as diyne, isocyanides, and bromoalkynes will be introduced. Furthermore,several click polymerization methods in aqueous media will be discussed. The “on water” effect facilitates polymerization in aqueous media more effectively than in conventional organic solvents. Additionally, many luminogens possessing aggregation-induced emission and natural characteristics (BioAIEgens) are developed in a water system. The synthesized polymers, small molecules, and BioAIEgens show unique characteristics and functions such as aggregation-induced emission (AIE), clusteroluminescence, bio-imaging ability, and stimuli-responsive response. With the aim of exploring polymerizations on/in water, we hope this talk could provide insight into polymerizations of water and triple-bond based monomers, as well as the preparation of functional materials under mild reaction conditions or through the utilization of water.

The global plastic waste crisis persists as a pressing environmental challenge, with conventional degradation methods revealing fundamental technical constraints. Current industrial-scale recycling approaches suffer from downcycling effect, restricted applicability, and concomitant microplastic generation, [1,2] which underscores the urgent demand for transformative recycling paradigms that harmonize operational simplicity, economic feasibility, and minimal resource expenditure.

Sunlight-drive decomposition represents a revolutionary paradigm, which operates under ambient conditions with near-zero energy input, positioning a scalable and environmentally benign management solution. [3] However, achieving complete decomposition while maintaining essential material performance constitutes a critical technological hurdle.

we present a transformative materials design strategy as a potential solution to the problem. This design philosophy stems from our previous discovery that a polydiacetylene containing short carboxylic acid side groups undergoes complete degradation into small molecules under sunlight in either air or aqueous environments, primarily through the cleavage of its C=C and C≡C bonds in the backbone. [4] Intriguingly, the topochemical polymerization mechanism inherent to polydiacetylenes is particularly advantageous for crystalline engineering plastics with regularly aligned polymer strands. Using industrial crystalline engineering plastic polyamide 6/10 (nylon 6/10, or PA610) as a model system, our design introduces diacetylene moieties within the strands of PA610 while maintaining the commercial-grade properties of the materials in terms of mechanical properties and transparency. When exposed to sunlight, the inter-chain topochemical polymerization among adjacent diacetylene units occurs, creating a crosslinked network embedding photodegradable elements in both crosslinkers and polymer strands. The derived material then completely degrades in natural environment within 5 months. 

This sunlight-responsive switching mechanism elegantly reconciles the conflicting requirements of structural robustness during service life and controlled degradability at end-of-life, establishing a new paradigm for sustainable materials engineering.