Aggregate (Hoboken, N.J.)最新文献

Near-infrared (NIR)-II fluorescence imaging-guided photothermal therapy (PTT) has attracted great research interest, and constructing donor-acceptor (D-A) electronic configurations has become an established approach to lower bandgap and realize NIR-II emission. However, very few π-conjugated phototheranostic agents can realize efficient NIR-II guided PTT using a clinically safe laser power density, implying that sufficient photothermal performance is still desired. In addition to the continuously refreshed photothermal conversion efficiency levels, the strategies that focus on enhancing light absorptivity have been rarely discussed and endow a new direction for enhancing PTT. Herein, a dimerization π-extension strategy is raised to synthesize π-conjugated dimers with A-D-A monomers. We observe that the light absorptivity (ε) of the dimers is strengthened three times owing to the enhanced electronic coupling effect as a result of the π-conjugation extension, thereby surpassing the 2-fold increase in chromophore numbers from the monomer to dimers. Thanks to the enhancement in light absorption, the dimers could generate much more photothermal heat than the monomer in in vivo PTT treatments. Therefore, an efficient anti-tumor outcome has been fulfilled by using dimers under a low laser power (0.3 W/cm²). Moreover, the dimers with extended π-conjugation structures become more favorable to the radiative excited state decay, thus exhibiting a distinguishing improvement in NIR-II imaging compared with monomer. Collectively, due to the improved light absorptivity, the dimers can gain superior NIR-II fluorescence brightness and photothermal performance over the recently reported material, which goes beyond the monomer in double doses for in vivo applications. All these results prove that dimerization is an effective strategy for designing high-performance phototheranostic materials.

The conversion of the biomass into eco-friendly fuels and chemicals has been extensively recognized as the essential pathway to achieve the sustainable economy and carbon neutral society. Lignin, as a kind of promising biomass energy, has been certified to produce the high-valued chemicals and fuels. Numerous efforts have been made to develop various catalysts for lignin catalytic conversion. Both metal-organic frameworks (MOFs) and covalent organic frameworks (COFs) belong to very important heterogeneous porous catalysts due to their regular porous structures, high specific surface area, and precisely tailored diversities. In the review, the first part focused on the catalytic conversion of lignin, lignin model compounds, and lignin derivatives using the pristine MOFs, functional MOF composites, and MOF-derived materials. The second part summarized the catalytic conversion of lignin model compounds using pristine COFs and functional COF composites. The review here mainly concentrated on the design of the materials, screening of catalytic conditions, and explorations of the corresponded mechanisms. Specifically, (1) we summarized the MOF- and COF-based materials for the effects on the catalytic transformation of lignin-related substances; (2) we emphasized the catalytic mechanism of C–C and C–O bonds cleavage together with the structure–activity relationships; (3) we in-depth realized the relationship between the chemical/electronic/structural properties of the MOF- and COF-based catalysts and their catalytic performance for lignin-related substances. Finally, the challenges and future perspectives were also discussed on the catalytic conversion of lignin-related substances by MOF- and COF-based catalysts.

In this study, Peng et al. established a logarithmic relationship between the nanoparticle size and fluorescence intensity based on hydrogen-bonded supramolecular assembly and aggregation-induced emission. The logarithmic relationship arises from the different nonradiative decay rates of monomers at the surface and within the interior of the nanoparticles, which can be effectively utilized for estimating nanoparticle sizes through fluorescence intensity measurements (e415).

This paper describes a type of triazine-based multicomponent metallacages with tunable structures through changing the chemical structures of the tetracarboxylic building blocks. These metallacages are used for selective SO₂ capture and conversion, which will promote the further applications of metallacages for the treatment of harmful gases (e408).

With the continuous development of the global information industry, the constant advancements in digital products have generated a growing need for electrochemical energy storage devices that are efficient, practical, and dependable. Supercapacitors, being a novel energy storage device with excellent performance and extended lifespan, have played a pivotal role in advancing the global information industry. The unique and precise structure of biomass materials and their incorporation significantly contributes to the performance of supercapacitors. This paper reviewed the application of biomass materials in supercapacitors in recent years. The challenges and opportunities facing the field were further discussed (e428).

Stable aromatic nitric acid radicals with open-shell singlet ground state and thermally excited triplet state were readily prepared and achieved ultra-wide absorption spectra in powders. These radical materials efficiently suppress radiation transitions and exhibit outstanding photothermal conversion performance, providing a rational design approach for solar-driven interfacial water evaporation active materials (e426).

Flexible wearables have attracted extensive interests for personal human motion sensing, intelligent disease diagnosis, and multifunctional electronic skins. However, the reported flexible sensors, mostly exhibited narrow detection range, low sensitivity, limited degradability to aggravate environmental pollution from vast electronic wastes, and poor antibacterial performance to hardly improve skin discomfort and skin inflammation from bacterial growth under long-term wearing. Herein, bioinspired from human skin featuring highly sensitive tactile sensation with spinous microstructures for amplifying sensing sensitivity between epidermis and dermis, a wearable antibacterial degradable electronics is prepared from degradable elastomeric substrate with MXene-coated spinous microstructures templated from lotus leaf assembled with the interdigitated electrode. The degradable elastomer is facilely obtained with tunable modulus to match the modulus of human skin with improved hydrophilicity for rapid degradation. The as-obtained sensor displays ultra-low detection limit (0.2 Pa), higher sensitivity (up to 540.2 kPa⁻¹), outstanding cycling stability (>23,000 cycles), a wide detection range, robust degradability, and excellent antibacterial capability. Facilitated by machine learning, the collected sensing signals from the integrated sensors on volunteer's fingers to the related American Sign Language are effectively recognized with an accuracy up to 99%, showing excellent potential in wireless human movement sensing and smart machine learning-enabled human–machine interaction.

Bacterial infection is a major threat to public health. Nanotechnology offers a solution by combining nanomaterials with antibacterial agents. The development of an effective nanocomposite against drug-resistant bacteria such as methicillin-resistant Staphylococcus aureus (MRSA) is highly important yet challenging. Here, an anti-MRSA core–shell structure is designed, containing antibacterial zeolitic imidazolate framework-8 (ZIF-8) as the core and bactericidal benzalkonium chloride (BAC) templated rough-surface mesostructured silica nanocomposite (RMSN) as the shell. The resultant ZIF-8@RMSN nanocomposite exhibits sustained release of BAC and zinc ions, effective disruption of the bacterial membrane, generation of oxidative damage of bacterial DNA, leakage of intracellular components, and finally bacterial death. Furthermore, the synergistic antibacterial mechanisms lead to enhanced biofilm elimination performance. In addition, the ZIF-8@RMSN-modified band-aid effectively combats MRSA infection in vivo. This work has provided a promising nanocomposite against MRSA-related infections.

Photoluminescence (PL) mechanisms of nontraditional luminogens (NTLs) have attracted great interest, and they are generally explained with intra/intermolecular through-space conjugation (TSC) of nonconventional chromophores. Here a new concept of nonaromatic through-bond conjugation (TBC) is proposed and it is proved that it plays an important role in the PL of NTLs. The PL behaviors of the three respective isomers of cyclohexanedione and gemdimethyl-1,3-cyclohexanedione were studied and correlated with their chemical and aggregate structures. These compounds show different fluorescence emissions as well as different concentration, excitation and solvent-dependent emissions. The compounds which undergo keto-enol tautomerism and hence with a conjugated ketone-enol structure (i.e., nonaromatic TBC) show more red-shifted emissions. TBC effect reduces the energy gaps and facilitates the formation of stronger TSC in the aggregate state. The compounds in the ketone-enol form are also prone to occur excited state intra/intermolecular proton transfer (ESIPT). The cooperative effect of nonaromatic TBC and TSC determines the PL behaviors of NTLs. This work provides a novel understanding of the PL mechanisms of NTLs and is of great importance for directing the design and synthesis of novel NTLs.

Fluorescent-patterned materials are widely used in information storage and encryption. However, preparing a patterned fluorescent display on a matrix currently requires a time-consuming (hours or even days) and complex multi-step process. Herein, a rapid and mild technique developed for the in-situ controllable synthesis of fluorescent nitrogen-doped carbon dots (NCDs) on eco-friendly transparent wood films (TEMPO-oxidized carboxyl wood film [TOWF]) within a few minutes was developed. A wood skeleton was employed as the carbon precursor for NCD synthesis as well as the matrix for the uniform and controlled distribution of NCDs. Moreover, the in-situ synthesis mechanism for preparing NCDs in TOWF was proposed. The resulting fluorescent wood films have excellent tensile strength (310.00 ± 15.57 MPa), high transmittance (76.2%), high haze (95.0%), UV-blocking properties in the full ultraviolet (UV) range, and fluorescent performance that can be modified by changing the heating parameters. Fluorescent patterning was simply achieved by regulating the in-situ NCD synthesis regions, and the fluorescent patterns were formed within 10 s. These fluorescent-patterned wood films can effectively store and encrypt information, and they can interact with external information through a transparent matrix. This work provides a green and efficient strategy for fabricating fluorescent information storage and encryption materials.