Stable and highly efficient fluorescent silicone elastomers have attracted tremendous attention. In this contribution, a series of fluorescent silicone elastomers are facilely fabricated by combining aggregation-induced emission (AIE)-active polymers with a silicone matrix. The investigated AIE-active macromolecules are synthesized by reversible addition− fragmentation chain-transfer polymerization of vinyl monomers containing a tetraphenylethylene pendant. Detailed experimental characterizations demonstrate that macromolecular fluorescent compounds have good dispersibility and leaching resistance in silicone elastomers. Especially, the fluorescence properties of the silicone elastomers can be modulated by changing the molecular weight or aggregation state of the fluorescent macromolecules. Moreover, the prepared fluorescent silicone films show multiple stimulus responsiveness to strain, temperature, and organic solvents. The present work provides a simple and universal strategy toward fluorescent silicone elastomers for both scientific research and future practical applications.
Chiral and circularly polarized luminescence (CPL) materials with multiple stimuli responses have become a focus of attention. Meanwhile, elastomers have found substantial applications in a wide variety of fields. However, how to design and construct chiral elastomers, in particular CPL-active elastomers, still remains an academic challenge. In the present study, chiral helical substituted polyacetylene is chemically bonded with polydimethylsiloxane (PDMS) by hydrosilylation to form a chiroptically active elastomer. A CPL-active film was further fabricated by adding achiral fluorophores. Compared with the corresponding chiral helical polymer, the chiral films show much enhanced thermal stability in terms of chiroptical properties. The films also demonstrate reversible tunability in optical activity and CPL property when being subjected to a stretching−restoring process and exposed to a solvent like toluene. Further, noticeable chiral amplification is observed when the chiral PDMS film is superimposed with a pure PDMS film. This interesting finding is proposed to be due to the photoreflectivity of PDMS. This study provides an alternative strategy to exploit novel CPL-active elastomer materials with multiple stimuli responsivity and tunability, which may open up new opportunities for developing novel chiroptical devices.
Purpose anterior cervical decompression and fusion is a common surgical procedure. Traditionally, experienced doctors observe X-ray films regularly examined by patients to determine postoperative conditions by observing the tiny movements between the limited vertebral bodies. But it is not accurate. This may lead to error diagnostics and serious deterioration of the condition and secondary injury to the patient and will also put a greater financial burden on them. Doctors need a quantitative standard to determine small motion with limited vertebral landmarks after surgery. Computer vision technology is needed to match the over-extension and over-flexion cervical vertebral body to provide objective measurement data for further quantification of intervertebral activity. Based on conventional scheme, the point mean square error is used as the evaluation criterion of the matching effect, and the iterative matching scheme is proposed to improve the stability of the original scheme. The cervical X-ray films of patients from the China–Japan Friendship Hospital were collected as samples to verify the reliability of the scheme. Compared with the existing image matching schemes based on feature points, our scheme is superior in matching effect, matching speed and stability. This scheme can provide a solid foundation for further assisting doctors in the study of rehabilitation after anterior cervical fusion.
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