Colored polymer microspheres have attracted significant attention in both academia and industry due to their unique optical properties and extensive application potential. However, achieving a uniform distribution of dyes within these microspheres remains a challenge, particularly when heavy concentrations of dye are used, as this can lead to aggregation or delamination, adversely affecting their application. Additionally, many dyes are prone to degradation or fading when exposed to light, heat, or chemicals, which compromises the long-term color stability of the microspheres. Consequently, the preparation of colored polymer microspheres with high stability continues to be a significant challenge. This review offers a comprehensive overview of the preparation techniques for colored polymer microspheres and their dyeing mechanisms, introducing the fundamental concepts of these microspheres and their applications in various fields, such as biomedicine, optical devices, and electronic display technologies. It further presents a detailed discussion of the different preparation methods, including physical adsorption, chemical bonding, and copolymerization. The advantages, limitations, and potential improvements of each method are explored, along with an analysis of the interactions between dyes and the polymer matrix, and how these interactions influence the properties of the microspheres, including their color uniformity, stability, and durability. Finally, the review discusses future perspectives on the development of colored polymer microspheres, highlighting the advancement of novel materials, innovations in preparation technology, and the exploration of potential new application areas.

With the widespread application of tagging materials, existing chemical tagging materials exhibit limitations in stability and detection under field conditions. This study introduces a novel magnetic detection scheme. Hydrophilic material-modified Fe₃O₄ nanoparticles (COOH-PEG@Fe₃O₄ NPs) were synthesized using the co-precipitation technique. The content of Fe₃O₄ nanoparticles in the magnetic tagging liquid can reach up to 10 wt% and remain stable in an aqueous phase system for seven days. This research details the preparation process, the characterization methods (IR, ¹HNMR, EDX, XRD, SEM, TEM, VSM, DLS), and the performance effects of the materials in magnetic tagging. Experimental results indicate that COOH-PEG@Fe₃O₄ NPs exhibit high remanence intensity (Br = 1.75 emu/g) and considerable stability, making it possible to quickly detect tagged liquids in the field using portable flux meters and optical pump magnetometers. This study provides new insights into the design and application of magnetic tagging materials, making it particularly suitable for long-term tagging and convenient detection in field scenarios.

Active Pharmaceutical Ingredients-Ionic liquids (API-ILs) can increase drug solubility and bioavailability of solid drugs without changing the structure of drug molecules. In the present work, nonivamide (pelargonic acid vanillylamide, PAVA) was used as the active drug and choline (Ch) and citric acid (CA) were selected as the ions to prepare PAVA–based ionic liquid ([Ch][PAVA] and [PAVA]₃ [CA]), respectively. The characterization and physical properties of [Ch][PAVA] and [PAVA]₃ [CA], such as FT–IR spectra, 1H NMR spectra, thermal stability and hydrophilicity, were investigated. And the irritant effects of the PAVA–based ionic liquids were measured by the animal irritation experiment. [Ch][PAVA] has higher decomposition temperatures, better hydrophilicity and comparable irritant effects. The results show that the PAVA–based ILs synthesized in this study may potentially serve as a promising novel riot control agent.