The implementation of gold-hydrogel core-shell nanomaterials in novel light-driven technologies requires the development of well-controlled and scalable synthesis protocols with precisely tunable properties. Herein, new insights are presented concerning the importance of using the concentration of gold cores as a control parameter in the seeded precipitation polymerization process to modulate—regardless of core size—relevant fabrication parameters such as encapsulation yield, particle size and shrinkage capacity. Controlling the number of nucleation points results in the facile tuning of the encapsulation process, with yields reaching 99% of gold cores even when using different core sizes at a given particle concentration. This demonstration is extended to the encapsulation of bimodal gold core mixtures with equally precise control on the encapsulation yield, suggesting that this principle could be extended to encapsulating cores composed of other materials. These findings could have a significant impact on the development of stimuli-responsive smart materials.
In recent years, hydrogel‐based soft materials with hybrid properties have found widespread use in various technological fields, including tissue engineering, soft actuators, and flexible electronics. The proper implementation of these smart multifunctional materials into real‐world applications requires the development of simple, cost‐effective, and large‐scale fabrication methods. Herein, a simple compression‐ and colloid‐based method is presented to fabricate responsive Au‐poly(N‐isopropylacrylamide) (pNIPAM) hybrid films using photopolymerizable resin containing Au‐pNIPAM core–shell microgels as building blocks. Uniform Au‐pNIPAM hybrid films of 25 × 25 mm with adjustable thickness in the micron‐size range (2.3–1.2 µm) w ere successfully fabricated on glass substrates and flexible commercial acetate sheets. The resulting flexible Au‐pNIPAM films exhibit robust optical and mechanical properties, even after repeated edge‐to‐edge bending cycle tests. Additionally, using patterned light to polymerize the Au‐pNIPAM films allows synthesizing of anisotropic Au‐pNIPAM microgels with high width‐to‐height aspect ratios, such as square, circular, and rectangular microgels, adding a new dimension to the proposed fabrication method.
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