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Biomimetic optical devices based on cellulose nanocrystals with tunable structural colors have received significant attention recently. However, the limited ability to control multicolor separation beyond simple single‐color modulation restricts its practical applications. Here, a diversified multicolor separation strategy for the cholesteric phase cellulose composite (CPCC) is presented. The CPCC is prepared by integrating a high‐concentration self‐assembled hydroxypropyl cellulose with a cross‐linked poly(acrylic acid‐acrylamide) (P(AA‐AM)) network. By adjusting the cross‐linking degree of P(AA‐AM) in CPCC, Thermally induced multicolor separation is achieved from a homochromatic state at room temperature to multicolor patterned display at elevated temperatures. Furthermore, by utilizing the electric heating effect of conductive carbon oil, the multicolor separation under low voltage is achieved, and based on this, pixelated electro‐thermochromic displays are developed. Additionally, magneto‐thermal multicolor separation induced by introducing FeNi3 nanoparticles is investigated with efficient magnetic induction heating ability into CPCC. The multicolor separation effect is further improved by pixelated distribution of FeNi3 nanoparticles and adjusting the concentration of FeNi3 in each pixel. Finally, thermochromism, electro‐thermochromic, and magneto‐thermochromic functionalities are integrated into the CPCC, achieving advanced multilevel information encryption. This multilevel approach of controlling multicolor separation significantly enhances the functionality of nanocellulose in various potential photonic applications. [ABSTRACT FROM AUTHOR]

Integration of photoluminescence (PL), especially the long‐lived room‐temperature phosphorescence (RTP), into periodic submicron structures to build multi‐optical morphology photonic crystals (PCs) is a trend for future optical devices but has proven extremely challenging. Here, an emerging general strategy for fabricating three‐optical morphology (tri‐state) SiO2‐based PCs by calcining monodisperse SiO2 nanospheres with carbon dots (CDs) encapsulated inside is reported. The resulting phosphorescent SiO2 nanospheres are unaffected by the type of surface defects or heteroatom doped in CDs, but rely on C─Si covalent bonds to stabilize the excited triplet state (T1). The high degree of integration of chemiluminescent molecules and physical unit arrays offers the possibility of PCs with RTP emission in various physical morphologies. The assembled tri‐state PCs exhibit vivid structural colors, blue PL and green RTP under different light stimulation. Additionally, an intelligent thermal‐responsive optically tri‐state PC gel is successfully fabricated by self‐assembly of colloidal particles in suspensions. The optical signals (including structural color, transmittance, PL, and RTP) of the gels exhibit complementary properties regulated by temperature in the reflection and transmission modes. The general strategy and multifunctionality of these tri‐state PCs and gels open new avenues for applications in decorative coatings, tri‐morphology recyclable smart windows, and information encryption. [ABSTRACT FROM AUTHOR]

Organic photosensitizers (PSs) can generate reactive oxygen species (ROS) via electron transfer (type I) and energy transfer (type II) pathways during photodynamic therapy (PDT). However, although numerous organic PSs have been constructed, the methods to optimize both type I and type II ROS generation are still not well explored. In this work, molecular engineering is applied to design three new organic PSs with varying triplet lifetimes and intersystem crossing (ISC) efficiency to achieve highly efficient type I&II ROS generation. The results reveal that after coated into nanoparticles (NPs) with DSPE‐PEG2000‐Biotin, the PS of mBDP‐PyH with the longest triplet lifetime and moderate ISC efficiency possesses good type II ROS and moderate type I ROS generation. With other properties being similar, the PS of mBDP‐2Py exhibits a shorter triplet lifetime, accompanied by concurrently reduced ROS generation for both types inside NPs. In contrast, the most potent PS of mBDP‐PyBr exhibits the shortest triplet lifetime but highly efficient ISC, with its NPs showing superior type I&II ROS generation. Moreover, both in vitro and in vivo experiments indicate that mBDP‐PyBr NPs display outstanding light toxicity under normoxic and hypoxic conditions. Overall, this study provides valuable guidance in designing effective organic PSs for PDT. [ABSTRACT FROM AUTHOR]

Amid the proliferation of counterfeit and shoddy products, it is imperative to develop efficient and reliable encryption and anticounterfeiting technologies. Here, we present a two-level information security system with encryption and anticounterfeiting functions that can exhibit multioptical states. A phase transition material of P-(N-isopropylacrylamide) (PNIPAM) film with a nanometer-sized inverse quasi-amorphous array (PIQA) is prepared using a sacrificial templating method. In the dry state, the PIQA film is highly transparent due to the collapse of internal pores, effectively concealing any preset information. When immersed in water, the nanometer-sized quasi-amorphous array of the PIQA film rapidly recovers, producing vibrant structural colors and revealing encrypted information. By simple increase of the temperature, the PIQA film undergoes a vibrant color change. This occurs because as the temperature increases, the PIQA film undergoes a phase transition, with its volume first expanding and then contracting. Correspondingly, the reflection peak wavelength of the PIQA film undergoes a red shift, followed by a blue shift. When the temperature exceeds 35 °C, phase separation occurs in the PIQA film, resulting in a white color. This feature for multiple color transformations solely through temperature increase serves as an authentication for accurate information. The reversible switching of multioptical states demonstrates great potential and advantages in the field of information security. [ABSTRACT FROM AUTHOR]

Fe2O3/ZnO/Ag ternary composite photocatalytic material was prepared by simple hydrothermal method, and its structure and photocatalytic properties were studied. The experimental results show that Fe2O3/ZnO/Ag exhibits better photocatalytic performance. After two hours of UV irradiation, the degradation rates of orange II and methyl orange reached 91.9% and 75.9%, respectively. The design and preparation of the photocatalyst provide a theoretical basis for the practical application of photocatalytic technology. [ABSTRACT FROM AUTHOR]

Low‐energy visible‐light‐activated carbon dots (CDs)‐based afterglow materials are difficult to realize due to the inherent aromatic carbon with high‐energy absorption and the lack of effective regulation. Here, a new strategy for visible‐light‐activated CDs is proposed by combining dual‐confinement and surface‐ionization, which employs NaOH for additional confinement and surface ionization of CDs in a single boric acid (BA) matrix. The comparison experiments show that: i) shifting the excitation from UV‐light to vis‐light is realized by enhancing the low‐energy surface states n→π* transition of the CDs by surface ionization of NaOH. ii) CDs are additionally protected by a more stable Na─O ionic bond after NaOH confinement, resulting in a brighter afterglow. iii) the energy gap (ΔEST) between the lowest singlet and triplet states is gradually shortened as increasing NaOH content, facilitating intersystem crossing, prolonging the lifetime of triplet excitons and efficiency. Further, vis‐light‐excited colorful afterglow powders are fabricated based on Förster Resonant Energy Transfer by combining the fluorescent dye 5‐carboxytetramethylrhodamine. Finally, advanced white‐light‐activated time‐resolved anti‐counterfeiting and intelligent traffic flashing signs are realized. The work may shed new light on the design of low‐energy‐activated afterglow materials and broaden the application scenarios in the daily lives of human society. [ABSTRACT FROM AUTHOR]

Sharing bus rapid transit (BRT) exclusive lanes with conventional buses is being considered to solve the problem of low utilization rate of BRT-exclusive lanes. However, the quantitative conditions and threshold that determine when to share need to be study. This paper took the common section of BRT and conventional bus lines as its research object. Practical investigation was conducted to analyze shared characteristics from multiple perspectives and explore influencing factors and mechanisms for sharing implementation. Based on the survey results, analytical models were established to quantify the influencing factors from three perspectives of road section, intersection, and bus stop. We selected departure volume of conventional buses as a threshold index and then summarized the constraints and the calculation process of sharing threshold. Finally, numerical examples of different scenarios were used to verify the feasibility and effectiveness of the method. The operation efficiency of the road section on exclusive lanes was the constraint on the lower limit of the shared threshold, while the upper limit was constrained by queuing probability or bus operation time under different intersections and stop spacing, which can provide reference for the shared setting of exclusive bus lanes. [ABSTRACT FROM AUTHOR]