Photochromic properties of color‐matching,double‐shelled microcapsules covalently bonded onto cotton fabric and applications to outdoor clothing

In this research, we aimed to apply color‐matching, double‐shelled microcapsules to deal with outdoor‐clothing sunscreen‐indicator identifications on cotton fabrics with a covalent‐bonding coating method; this method allows one to display both the UV intensity and a warning. The color‐property characteristics of color‐matching‐double‐shelled‐photochromic‐microcapsule–treated patterns on cotton fabrics under various sunshine irradiation intensities are very close to those of inkjet‐printing color‐gradation patterns, which indicate sunshine irradiation intensities. Color‐matching, double‐shelled microcapsules were obtained by the addition of red double‐shelled microcapsules into yellow double‐shelled microcapsules. We increased the weight ratio of the red microcapsules and added blue double‐shelled microcapsules into the red double‐shelled microcapsules when the weight ratio of blue microcapsules was increased. Color‐matching, double‐shelled photochromic microcapsules, whose yellow/red/blue weight ratios were 5.6/0/0, 4.8/0.8/0, 2.4/3.2/0, and 0.8/4.8/0–0/0/5.6, presented distinct color‐property characteristic changes under various irradiation intensities and presented a good color identification; a rather dark, bright color; and good laundering durability of covalent bonding on cotton fabrics. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 44698.     

Fabrication and photocatalytic behavior of a novel nanocomposite hydrogels containing Fe‐octacarboxylic acid phthalocyanine

A novel poly(ethylene glycol)‐based nanocomposite hydrogels containing Fe‐octacarboxylic acid phthalocyanine (FeOCAP)/magnetic attapulgite was successfully synthesized by in situ polymerization. Fourier transform infrared spectroscopy result showed the FeOCAP/magnetic attapulgite was successfully introduced into the hydrogels matrix. Besides, the hydrogen bond interactions existed between FeOCAP/attapulgite and hydrogels, which acted as the crosslink points in the hydrogels network, and meanwhile, stabilized the nanoparticles in hydrogel without phase separation. Photocatalytic activity studies confirmed that the as‐prepared nanocomposite hydrogels had excellent photocatalytic activity for rhodamine B photodegradation, as compared to the pure hygrogels. The rhodamine B removal percentage of the hydrogels could reach nearly 100% and the kinetics of photocatalytic degradation reaction was described by the Langmuir–Hinshelwood kinetics models. The hydrogels could be reused more than five times without losing any photodegradation ability, which indicated that the hydrogels would be potentially useful in dyes wastewater treatments. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45428.     

Native Chemical Ligation Directed by Photocleavable Peptide Nucleic Acid (PNA) Templates

A novel peptide–peptide ligation strategy is introduced that has the potential to provide peptide libraries of linearly or branched coupled fragments and will be suited to introduce simultaneous protein modifications at different ligation sites. Ligation is assisted by templating peptide nucleic acid (PNA) strands, and therefore, ligation specificity is solely encoded by the PNA sequence. PNA templating, in general, allows for various kinds of covalent ligation reactions. As a proof of principle, a native chemical ligation strategy was elaborated. This PNA‐templated ligation includes easy on‐resin procedures to couple linkers and PNA to the respective peptides, and a traceless photocleavage of the linker/PNA oligomer after the ligation step. A 4,5‐dimethoxy‐2‐nitrobenzaldehyde‐based linker that allowed the photocleavable linkage of two bio‐oligomers was developed.     

Ultrafast Photoconversion Dynamics of the Knotless Phytochrome SynCph2

The family of phytochrome photoreceptors contains proteins with different domain architectures and spectral properties. Knotless phytochromes are one of the three main subgroups classified by their distinct lack of the PAS domain in their photosensory core module, which is in contrast to the canonical PAS-GAF-PHY array. Despite intensive research on the ultrafast photodynamics of phytochromes, little is known about the primary kinetics in knotless phytochromes. Here, we present the ultrafast P_r ⇆ P_fr photodynamics of SynCph2, the best-known knotless phytochrome. Our results show that the excited state lifetime of P_r* (~200 ps) is similar to bacteriophytochromes, but much longer than in most canonical phytochromes. We assign the slow P_r* kinetics to relaxation processes of the chromophore-binding pocket that controls the bilin chromophore’s isomerization step. The P_fr photoconversion dynamics starts with a faster excited state relaxation than in canonical phytochromes, but, despite the differences in the respective domain architectures, proceeds via similar ground state intermediate steps up to Meta-F. Based on our observations, we propose that the kinetic features and overall dynamics of the ultrafast photoreaction are determined to a great extent by the geometrical context (i.e., available space and flexibility) within the binding pocket, while the general reaction steps following the photoexcitation are most likely conserved among the red/far-red phytochromes.     

Synthesis of 5,5′‐Diformyl‐2,2′‐difuran from 2‐Furfural by Photochemical Aryl Coupling

The synthesis of 5,5′‐diformyl‐2,2′‐difuran (IUPAC name: [2,2′‐bifuryl]‐5,5′‐dicarbaldehyde) in good yields by the intermolecular coupling of 2‐furfural and 5‐bromo‐2‐furfural has been achieved. Optimum yields were obtained when mixtures of the substrates in acetonitrile were treated with polyvinylpyridine powder (Reillex 402), and irradiated with UV light through a quartz filter. Low yields of coupling product were obtained in the absence of this base or if hydrocarbon solvents were used. A mechanistic pathway involving a transient exciplex intermediate has been proposed.     

后处理中锕系元素和贵金属元素光化学调价方法

PUREX流程是目前世界上唯一实现工业化应用的后处理流程,该流程的关键技术之一在于调控Pu、Np、Tc等元素的价态。传统上PUREX流程采用化学法调节元素价态,但化学调价有时会遇到困难,比如在硝酸体系下用化学试剂将Np调节至单一价态十分困难。和化学法相比,光化学调价具有方法简单、二次废物体积少、方便远程控制、对材料耐辐照要求不高等优点。将光化学调价和溶剂萃取结合很有潜力实现金属元素的高效分离,只依靠光化学方法将金属离子还原至单质状态也可以实现金属元素的分离和回收。此外,紫外光的照射还能在室温下显著促进UO_2在硝酸溶液中的溶解。