To address the issues of insufficient protection and poor durability in concrete during service, this study developed a novel polymer–silicate composite gel system by combining silane with fluorocarbon resin emulsion and applied it to mortar specimens. The chloride ion resistance enhancement of mortar provided by the novel gel system was evaluated using the RCM method and natural chloride ion penetration tests, with SEM images employed to analyze its anti-permeation mechanism. Results indicate that the chloride ion migration coefficient of the novel composite gel system is 4.91 × 10−12 m2/s, representing a 63.97% reduction compared to the single fluorocarbon gel system. Within the 0–5 mm depth range, free chloride ion contents at 14, 28, and 56 days decreased by 55.35%, 50.10%, and 43.64%, respectively, demonstrating excellent resistance to chloride penetration. Acid and alkali resistance tests demonstrated that the system retained the inherent corrosion resistance of the fluorocarbon component. Carbonation tests demonstrated that the system exhibited a slight decrease in carbonation resistance compared with the pure fluorocarbon gel system, while still maintaining a satisfactory performance level. Overall, the polymer-silicate composite gel system significantly enhanced the mortar’s resistance to chloride ion penetration.
Polymer-based actuators have gained extensive attention owing to their potential applications in aerospace, soft robotics, etc. However, poor mechanical properties, the inability of multi-stimuli response and programmable deformation, and the costly fabrication procedure have significantly hindered their practical application. Herein, these issues are overcome via a simple and scalable one-step molding method. The actuator is fabricated by hot-pressing commercial unidirectional carbon fiber/epoxy prepregs with a commodity PC membrane. Notable CTE differences between the CF and PC layers endow the bilayer actuator with fast and reliable actuation deformation. Benefiting from the high strength of CF, the actuator exhibits excellent mechanical performance. Moreover, the anisotropy of CF endows the actuator with design flexibility. Furthermore, the multifunction of CF makes the actuator capable of responding to thermal, optical, and electrical stimulation simultaneously. Based on the bilayer actuator, we successfully fabricated intelligent devices such as light-driven biomimetic flowers, intelligent grippers, and gesture-simulating apparatuses, which further validate the programmability and multi-stimuli response characteristics of this actuator. Strikingly, the prepared gripper possesses a grasping capacity approximately 31.2 times its own weight. It is thus believed that the concept presented paves the way for building next-generation robust robotics.
An experimental investigation was conducted to study the effect of initiator content and polymerization temperature on the mechanical and bonding properties of polyacrylate mortar. Initiator content was controlled in 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9 and 1.0% and polymerization temperature was set at −20, 0, 20, 40, and 60 °C in aggregation process, respectively. The mixture of butyl methacrylate (BMA), benzoyl peroxide (BPO) and N, N-dimethylaniline (DMA) was added to the aggregate composed of quartz sand and silica fume (SF) according to the ratio of monomer to aggregate of 1:4. Results showed that compressive, flexural, tensile, and bonding strengths of polyacrylate mortar decreased with increasing temperature but increased with higher initiator content. The optimal initiator content was 0.6%. Although the highest strength was observed at −20 °C, this curing condition is not easy to achieve in practice and should be considered as laboratory optimization. According to the room temperature, 20 °C can be selected as the best polymerization temperature. SEM observations indicated that the polyacrylate cementitious material cross-linked to form a film, with a dense polymer distribution at the interface that improved interfacial continuity. These findings provide mechanistic insight for optimizing initiator content and curing conditions to enhance the mechanical and bonding performance of polyacrylate-based cementitious composites.