Confinement of Sustainable Carbon Dots Results in Long Afterglow Emitters and Photocatalyst for Radical Photopolymerization.

Sustainable carbon dots based on cellulose, particularly carboxymethyl cellulose carbon dots (CMCCDs), were confined in an inorganic network resulting in CMCCDs@SiO2. This resulted in a material exhibiting long afterglow covering a time frame of several seconds also under air. Temperature-dependent emission spectra gave information on thermally activated delayed fluorescence (TADF) and room temperature phosphorescence (RTP) while photocurrent experiments provided a deeper understanding of charge availability in the dark period, and therefore, its availability on the photocatalyst surface. The photo-ATRP initiator, ethyl α-bromophenylacetate (EBPA), quenched the emission from the millisecond to the nanosecond time frame indicating participation of the triplet state in photoinduced electron transfer (PET). Both free radical and controlled radical polymerization based on photo-ATRP protocol worked successfully. Metal-free photo-ATRP resulted in chain extendable macroinitiators based on a reductive mechanism with either MMA or in combination with styrene. Addition of 9 ppm Cu2+ resulted in Mw/Mn of 1.4 while an increase to 72 ppm improved uniformity of the polymers; that is Mw/Mn=1.03. Complementary experiments with kerria laca carbon dots confined materials, namely KCDs@SiO2, provided similar results. Deposition of Cu2+ (9 ppm) on the photocatalyst surface explains better uniformity of the polymers formed in the ATRP protocol.

Metabolomic profiling reveals decreased serum cysteine levels during gestational diabetes mellitus progression.

Gestational diabetes mellitus (GDM) is a pregnancy-related metabolic disorder associated with short-term and long-term adverse health outcomes, but its pathogenesis has not been clearly elucidated. Investigations of the dynamic changes in metabolomic markers in different trimesters may reveal the underlying pathophysiology of GDM progression. Therefore, in the present study, we analyzed the metabolic profiles of 75 women with GDM and 75 women with normal glucose tolerance (NGT) throughout the three trimesters. We found that the variation trends of 38 metabolites were significantly different during GDM development. Specifically, longitudinal analyses revealed that cysteine (Cys) levels significantly decreased over the course of GDM progression. Further study showed that Cys alleviated GDM in female mice at gestational day 14.5 possibly by inhibiting phosphoenolpyruvate carboxykinase to suppress hepatic gluconeogenesis. Taken together, these findings suggest that the Cys metabolic pathway might play a crucial role in GDM and that Cys supplementation represents a potential new treatment strategy for GDM patients.

Light-Mediated Polymerization Catalyzed by Carbon Nanomaterials.

Carbon nanomaterials, specifically carbon dots and carbon nitrides, play a crucial role as heterogeneous photoinitiators in both radical and cationic polymerization processes. These recently introduced materials offer promising solutions to the limitations of current homogeneous systems, presenting a novel approach to photopolymerization. This review highlights the preparation and photocatalytic performance of these nanomaterials, emphasizing their application in various polymerization techniques, including photoinduced i) free radical, ii) RAFT, iii) ATRP, and iv) cationic photopolymerization. Additionally, it discusses their potential in addressing contemporary challenges and explores prospects in this field. Moreover, carbon nitrides, in particular, exhibit exceptional oxygen tolerance, underscoring their significance in radical polymerization processes and allowing their applications such as 3D printing, surface modification of coatings, and hydrogel engineering.

Room-temperature phosphorescent materials derived from natural resources.

Room-temperature phosphorescent (RTP) materials have enormous potential in many different areas. Additionally, the conversion of natural resources to RTP materials has attracted considerable attention. Owing to their inherent luminescent properties, natural materials can be efficiently converted into sustainable RTP materials. However, to date, only a few reviews have focused on this area of endeavour. Motivated by this lack of coverage, in this Review, we address this shortcoming and introduce the types of natural resource available for the preparation of RTP materials. We mainly focus on the inherent advantages of natural resources for RTP materials, strategies for activating and enhancing the RTP properties of the natural resources as well as the potential applications of these RTP materials. In addition, we discuss future challenges and opportunities in this area of research.

Room temperature phosphorescence from natural wood activated by external chloride anion treatment.

Producing afterglow room temperature phosphorescence (RTP) from natural sources is an attractive approach to sustainable RTP materials. However, converting natural resources to RTP materials often requires toxic reagents or complex processing. Here we report that natural wood may be converted into a viable RTP material by treating with magnesium chloride. Specifically, immersing natural wood into an aqueous MgCl2 solution at room temperature produces so-called C-wood containing chloride anions that act to promote spin orbit coupling (SOC) and increase the RTP lifetime. Produced in this manner, C-wood exhibits an intense RTP emission with a lifetime of ~ 297 ms (vs. the ca. 17.5 ms seen for natural wood). As a demonstration of potential utility, an afterglow wood sculpture is prepared in situ by simply spraying the original sculpture with a MgCl2 solution. C-wood was also mixed with polypropylene (PP) to generate printable afterglow fibers suitable for the fabrication of luminescent plastics via 3D printing. We anticipate that the present study will facilitate the development of sustainable RTP materials.

Sensing Leakage of Electrolytes from Magnesium Batteries Enabled by Natural AIEgens.

The potential for leakage of liquid electrolytes from magnesium (Mg) batteries represents a large hurdle to future application. Despite this, there are no efficient sensing technologies to detect the leakage of liquid electrolytes. Here, we developed a sensor using laccaic acid (L-AIEgen), a naturally occurring aggregation-induced emission luminogen (AIEgens) isolated from the beetle Laccifer lacca. L-AIEgen showed good selectivity and sensitivity for Mg2+, a universal component of electrolytes in Mg batteries. Using L-AIEgen, we then produced a smart film (L-AIE-F) that was able to sense leakage of electrolytes from Mg batteries. L-AIE-F showed a strong "turn-on" AIE-active fluorescence at the leakage point of electrolyte from model Mg batteries. To the best of our knowledge, this is the first time that AIE technology has been used to sense the leakage of electrolytes.

Structural materials with afterglow room temperature phosphorescence activated by lignin oxidation.

Sustainable afterglow room temperature phosphorescence (RTP) materials, especially afterglow RTP structural materials, are crucial but remain difficult to achieve. Here, an oxidation strategy is developed to convert lignin to afterglow materials with a lifetime of ~ 408 ms. Specifically, lignin is oxidized to give aromatic chromophores and fatty acids using H2O2. The aromatic chromophores are locked by a fatty acid-based matrix by hydrogen bonds, triggering enhanced spin orbit coupling and long afterglow emission. More interestingly, motivated by this discovery, an auto fabrication line is built to convert wood (natural structural materials) to wood with afterglow RTP emission (RTP wood) via in situ oxidation of naturally-occurring lignin located in the wood cell walls to oxidized lignin (OL). The as-prepared RTP wood exhibits great potential for the construction of sustainable afterglow furniture. With this research we provide a new strategy to promote the sustainability of afterglow RTP materials and structural materials.

Sustainable Afterglow Room-Temperature Phosphorescence Emission Materials Generated Using Natural Phenolics.

Long-lived afterglow room-temperature phosphorescence (RTP) from natural phenolics has seldom been reported yet this is essential for the development of sustainable afterglow RTP materials. With this research, we have prepared sustainable afterglow RTP materials (GA@SA) with a lifetime of up to ≈934.7 ms by embedding gallic acid (GA) within a Ca2+ -crosslinked sodium alginate (SA) matrix. Theoretical simulations indicate that the restricted carbonyl moieties of the GA and H-type aggregates of GA in a SA matrix promoted the spin orbit coupling (SOC) of GA and induced afterglow emission. Moreover, afterglow RTP emission could be produced by embedding different types of natural phenolics such as, tannic acid, caffeic acid and chlorogenic acid into Ca2+ -crosslinked networks of SA. As an illustration of potential applications, GA@SA was used to prepare anti-counterfeit afterglow clothing and paper. This work provides an innovative method for the activation of long-lived afterglow RTP from sustainable phenolics.

Distinct Sustainable Carbon Nanodots Enable Free Radical Photopolymerization, Photo-ATRP and Photo-CuAAC Chemistry.

Carbon nanodots (CDs) originating from different biomass result in different activities to sensitize photo-ATRP and photo-CuAAC reaction protocols with visible light. Free radical polymerization of tri(propylene glycol)diacrylate also exhibited a good efficiency using CDs in combination with an iodonium salt employing LEDs emitting either at 405 nm, 525 nm or 660 nm. Photo-ATRP experiments confirmed controlled polymerization conditions using CuII at the ppm scale resulting in dispersities between 1.06 to 1.10. Chain end fidelity was successfully provided by chain extension and block copolymerization additionally approving the living feature of polymerization using a CD synthesized from lac dye comprising olefinic moieties in the originating biomass. By global analysis, time resolved fluorescence measurements indicated the appearance of several emitting species contributing to the reactivity of the excited states. Different cytotoxic response appeared following the answer of MCF-10A cells in a flow cytometry assay; that is 400 µg mL-1 . Thus, cell viability was greater 80 % in the case of CD-2-CD-5 while that of CD-1 was close to 70 %.

Preparation and Characterization of Antioxidative and UV-Protective Larch Bark Tannin/PVA Composite Membranes.

In order to prepare functional materials for antioxidant and ultraviolet (UV)-protective green food packaging, condensed tannin, previously extracted from larch bark, was mixed with polyvinyl alcohol (PVA), and then the mixture was used to cast composite membranes. An antioxidative assay using 1,1-diphenyl-2-picrylhydrazyl (DPPH)-a free radical scavenger-and starch⁻potassium iodide oxidation⁻discoloration analyses showed that the composite membranes have good antioxidative activities. The low UV transmission and protective effect of the composite films on vitamin E indicated the UV protection ability of the composite membranes. Both larch bark tannin and PVA are rich in hydroxyl groups; scanning electron microscopy analysis demonstrated their compatibility. Also, the mechanical and crystallization properties of the composite membranes did not significantly decrease with the addition of larch bark tannin.