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The redshift of the charge transfer band (CTB) edge of phosphor induced by temperature rise is pervasively accompanied by antithermal quenching. Accordingly, exploring the mechanism of the CTB redshift is thus not only propitious for optimizing the sensitivity of optical thermometry but also tenders a new idea for the design of antithermal quenching phosphors. Herein, a family of YP 1-x V x O 4 :Eu3+ phosphors were designed via the V5+/P5+ ion substitution strategy. With the increase of the V5+ ratio, the relative integral intensity of the 5D 0 →7F 2 transition multiplies from 1.25 to 28.67 times under CTB edge excitation. Moreover, by Gaussian fitting, the reduction degree of vanadate band gap energy 1E (1T 1)→1B 2 (1T 2), 1A 2 (1T 1)→1B 2 (1T 2) increased from 0.122 eV and 0.065 eV to0.162 eV and 0.083 eV, respectively, in the range of 303–523 K. Both reveal an enhance in redshift of the excitation spectra. The decrease of charge transfer state (CTS) energy level and the alteration of photoelectron thermal population are two mechanisms that induce CTB redshift. Specifically, the decrease of the CTS level is dominant in the YPO 4 :Eu3+ sample, and the thermal population of the higher vibrational levels of the VO 4 3−ground state is dominant in the presence of a tiny amount of V5+ doping. In addition, according to the experimental phenomenon, a dual-mode temperature sensing scheme based on excitation intensity ratio (EIR) and single band ratiometric (SBR) is proposed. Y 0.9 P 0.1 V 0.9 O 4 :0.1Eu3+ achieves a maximum sensitivity of S r-max = 4.040 % K−1 and a minimum temperature determination uncertainty of δT = 0.124 K at 323 K, which excellent performance indicates that this is a promising non-contact optical thermometer. [Display omitted] [ABSTRACT FROM AUTHOR]

Conventional polysaccharide films are flammable and susceptible to bacterial growth, decreasing the potential in practical applications such as bio-based and active food packaging. In this study, the nontoxic naturally occurring compound phytic acid (PA) was introduced to a blended film of κ-carrageenan (κC) and carboxylated cellulose nanofibrils (CCNF) to overcome these disadvantages. Compared with the κC-CCNF-PA 0 film, the κC-CCNF-PA 24 film possessed improved elongation at break (41%), water vapor permeability (3.46 g m−1 Pa−1 s−1 × 10−8) and oxygen permeability (1.50 cm3 mm−2 Pa−1 day−1 × 10−12). Thermogravimetric analysis, limiting oxygen index and actual flame-burning behaviors revealed good flame retardancy of the prepared films with the increase in PA. When the PA content reached 18% and 9%, the antibacterial rate against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) reached 100%, respectively. The cooked pork samples packaged by κC-CCNF-PA 24 exhibited lower values of malondialdehyde (0.61 mg kg−1) and total viable count (8 CFU g−1) compared with those by κC-CCNF-PA 0 film (0.99 mg kg−1, 447 CFU g−1). On the basis of these results, we believe that the sustainable and clean strategy provides an opportunity to improve and functionalize very brittle and flammable polysaccharide-based films. [Display omitted] • The κ-carrageenan/carboxylated cellulose nanofibrils/phytic acid film was prepared. • Phytic acid weakened the gelation degree of κ-carrageenan. • The film showed improved water vapor and oxygen permeability. • The flame retardance and antibacterial properties were endowed by phytic acid. • The prepared film exhibited excellent preservation effect on cooked pork. [ABSTRACT FROM AUTHOR]

Intelligent films monitoring food quality are potential to use in people's life. The safety and sensitivity are of great importance. In this study, a dual synergistic design was developed to construct a safely and sensitively smart film in which quaternary ammonium groups modified rice straw fiber (CRSF) attached bromothymol blue (BTB) was embedded into an anion κ-carrageenan/carboxymethyl cellulose (CMC) matrix. SEM results revealed the good interfacial compatibility between the matrix and the modified fiber. Substitution degree (DS) of quaternary ammonium groups and addition amount of CRSF-BTBs interestingly affected the properties of the film. That containing 1% CRSF-BTB with DS of 19.3% exhibited distinguishable colorimetric response in only 3.0 s at humidity of 75.0% with 0.8 mL of ammonia, and lower BTB release rate of 2.87% in 95% ethanol solution. The film displayed visible color changes from yellow to dark-blue as meat freshness decreased. This study provides a novel strategy to develop a highly smart film for insuring the food safety. [Display omitted] • The cationic lignocellulose particle with different DSs was designed as a carrier. • The amine-sensitive indicator was prepared by attaching BTBs on cationic particle. • The indicator was embedded into κ-carrageenan/CMC matrix to form a smart film. • The film spent only 3.0 s responding to 0.8 mL of NH 3 at humidity of 75.0%. • The colorimetric film could promisingly monitor the quality of pork and fish. [ABSTRACT FROM AUTHOR]

[Display omitted] • A sandwich structural Ni/Fe 3 O 4 /Ni/paper with a honeycomb surface was designed. • The absorption increased with the loaded capacity of Fe 3 O 4 increasing. • The EMI SE of the Ni/Fe 3 O 4 /Ni/cellulose paper reached 41.88 dB. Highly efficient shielding materials with an excellent electromagnetic wave absorption have gained increased attention. A new design was used to provide cellulose paper with a high electromagnetic shielding effectiveness (EMI SE) and improve the absorption performance by constructing an asymmetry sandwich structure that consisted of a dense nickel coating, Fe 3 O 4 nanoparticles and a porous nickel layer. This unique structure caused a "multiple reflection-absorb-reflection" process when the electromagnetic waves penetrated the sample. The EMI absorption (SE A) and total SE (SE T) increased with Fe 3 O 4 absorption time increasing at 8.2–12.4 GHz, which was attributed to the synergistic effect between porous nickel layer and Fe 3 O 4 nanoparticles. The SE A and SE T of the sample with a thickness of 0.195 mm can achieved 18.57 and 41.88 dB, respectively. The design was conducive to improving the magnetic and corrosion resistance properties. This study provided a novel path to obtain a low cost and lightweight electromagnetic shielding material that can reduce secondary radiation. [ABSTRACT FROM AUTHOR]