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Thermochromic poly(N‐isopropyl acrylamide) (PNIPAM) photonic crystal gels based on 1D magnetically assembling colloidal nanocrystal clusters have attracted much attention due to its convenient preparation process, striking color response, and good mechanical strength. However, there remain challenges to broaden the thermochromic range and improve the sensitivity for their iridescent color display. Here, a PNIPAM photonic gel with wide thermochromic range and high sensitivity is prepared by using four‐arm star poly(ethylene glycol) acrylamide (PEGAAm) as cross‐linker at appropriately reduced magnetic field strength as well as cross‐linker content. PEGAAm improves the homogeneity of the microstructure in PNIPAM photonic gel and thus maintains the structure colors at a wide temperature range from room temperature to 44 °C. The reduced magnetic field strength of 70 Gs and low cross‐linker content (the molar ratio of monomer to cross‐linker of 300:1) lead to a large initial lattice spacing of the photonic gel and thus wide diffraction wavelength migration of 194 nm. This optimized PNIPAM gel exhibits vivid iridescent colors from orange–red to indigo blue as temperature increases from 20 to 44 °C with satisfactory repeatability. Therefore, it may be an ideal candidate for temperature sensors and displays with utility and accuracy such as low‐temperature burns.

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A greater number of consumers are using social networks to express their feedback about the level of service provided by hotels. Online reviews from patrons can be used as a forum to enhance the level of service of hotels. Customer reviews are indeed a reliable and dependable source that aid diners in determining the quality of their cuisine. It is critical to develop techniques for evaluating client feedback on hotel services. In order to accurately anticipate the consumers' decision-making behaviors based on hotel internet evaluations, this study proposes a novel K-Means Clustered Support Vector Machine (KMC+SVM) technique. Principal Component Analysis (PCA) is employed to determine the characteristics from the preprocessed data while the Min-Max normalization approach is used to standardize the raw data. The performance of the suggested technique is then evaluated and contrasted with a few other methods that are currently in use in terms of accuracy, sensitivity, RMSE, and MAE. The findings demonstrated that segmenting customers based on their online evaluations can accurately predict their choices and assist hotel management in establishing priorities for service quality enhancements.

Thermochromic microspheres based on poly(N‐isopropylacrylamide) attract much attention in detection and sensor due to the noticeable color response and fast response rate. However, some issues such as uneven color display and narrow coloration range still limit their practical applications. Herein, novel thermochromic microspheres with homogeneous color displays and wide thermochromic range are designed by combining the microfluidic technology with the magnetically‐induced self‐assembly technique and copolymerizing acrylamide (AM) with N‐isopropylacrylamide. The photonic crystal structure with especially even colors is fast and conveniently constructed by magnetic assembly. The addition of AM makes the microspheres more hydrophilic and thus leading to a broader coloration range. The relationship between the structural color display and both the microstructures of photonic crystals and the thermo‐responsive properties of gel matrix are elucidated. The detectable temperature of microspheres rises to as high as 60°C, and displays bright iridescent color variations from orange to blue‐violet in the heating process. Importantly, their shrinking or swelling equilibrium can be reached in 80 and 105 s. Such microspheres are successfully used to visually indicate the appropriate temperature of enzymatic reaction, and have great potential in practical applications such as visual temperature detection and efficiency monitoring of chemical reactions.