Conformal Nanocoatings with Uniform and Controllable Thickness on Microstructured Surfaces: A General Assembly Route

Radiative Warming Glass for High-Latitude Cold Regions

Traditional window glazing, with inherently adverse energy-efficient optical properties, leads to colossal energy losses. Energy-saving glass requires a customized optical design for different climate zones. Compared with the widely researched radiative cooling technology which is preferable to be used in low-altitude hot regions; conversely in high-latitude cold regions, high solar transmittance (Tsol) and low mid-infrared thermal emissivity (εMIR) are the key characteristics of high-performance radiative warming window glass, while the current low-emissivity (low-e) glass is far from ideal. To address this issue, Drude's theory is used to numerically design a near-ideal film with specified electron density (ne) and electron mobility (µe). The fabricated hydrogen-doped indium oxide (IHO) could achieve high Tsol (0.836) and low εMIR (0.117). Energy-saving simulations further reveal a substantial decrease in annual heating energy consumption up to 6.6% across high-latitude regions (climate zones 6 to 8), translating to a corresponding reduction in CO2 emissions (20.0 kg m-2), outperforming 1165 high performance commercial low-e glass. This radiative warming glass holds the promise of making a significant contribution to sustainable building energy savings specifically for high-latitude cold regions, advancing the goal of carbon neutrality.

Photonic Crystal-Integrated Optoelectronic Devices with Naked-Eye Visualization and Digital Readout for High-Resolution Detection of Ultratrace Analytes

The detection of ultratrace analytes is highly desirable for the non-invasive monitoring of human diseases. However, a major challenge is fast, naked-eye, high-resolution ultratrace detection. Herein, a rectangular 3D composite photonic crystal (PC)-based optoelectronic device is first designed that combines the sensitivity-enhancing effects of PCs and optoelectronic devices with fast and real-time digital monitoring. A crack-free, centimeter-scale, mechanically robust ellipsoidal composite PCs with sufficient hardness and modulus, even exceeding most plastics and aluminum alloys, are developed. The high mechanical strength of ellipsoidal composite PCs allows them to be hand-machined into rectangular geometries that can be conformally covered with the centimeter-scale flat light-detection area without interference from ambient light, easily integrating 3D composite PC-based optoelectronic devices. The PC-based device's signal-to-noise ratio increases dramatically from original 30-40 to ≈60-70 dB. Droplets of ultratrace analytes on the device are identified by fast digital readout within seconds, with detection limits down to 5 µL, enabling rapid identification of ultratrace glucose in artificial sweat and diabetes risk. The developed 3D PC-based sensor offers the advantages of small size, low cost, and high reliability, paving the way for wider implementation in other portable optoelectronic devices.

Superior Hard but Quickly Reversible Si-O-Si Network Enables Scalable Fabrication of Transparent, Self-Healing, Robust, and Programmable Multifunctional Nanocomposite Coatings

A coating with programmable multifunctionality based on application requirements is desirable. However, it is still a challenge to prepare a hard and flexible coating with a quick self-healing ability. Here, a hard but reversible Si-O-Si network enabled by aminopropyl-functionalized poly(silsesquioxane) and triethylamine (TEA) was developed. On the basis of this Si-O-Si network, basic coatings with excellent transparency, hardness, flexibility, and quick self-healing properties can be prepared by filling soft polymeric micelles into hard poly(silsesquioxane) networks. The highly cross-linked continuous network endows the coating with a hardness (H = 0.83 GPa) higher than those of most polymers (H < 0.3 GPa), while the uniformly dispersed micelles decrease the Young's modulus (E = 5.89 GPa) to a value as low as that of common plastics, resulting in excellent hardness and flexibility, with an H/E of 14.1% and an elastic recovery rate (W_e) of 86.3%. Scratches (∼50 μm) on the coating can be healed within 4 min. The hybrid composition of poly(silsesquioxane) networks also shows great advantages in integration with other functional components to realize programmable multifunctionality without diminishing the basic properties. This nanocomposite design provides a route toward the preparation of materials with excellent comprehensive functions without trade-offs between these properties.

Simple Self-Assembly Strategy of Nanospheres on 3D Substrate and Its Application for Enhanced Textured Silicon Solar Cell

Nanomaterials and nanostructures provide new opportunities to achieve high-performance optical and optoelectronic devices. Three-dimensional (3D) surfaces commonly exist in those devices (such as light-trapping structures or intrinsic grains), and here, we propose requests for nanoscale control over nanostructures on 3D substrates. In this paper, a simple self-assembly strategy of nanospheres for 3D substrates is demonstrated, featuring controllable density (from sparse to close-packed) and controllable layer (from a monolayer to multi-layers). Taking the assembly of wavelength-scale SiO₂ nanospheres as an example, it has been found that textured 3D substrate promotes close-packed SiO₂ spheres compared to the planar substrate. Distribution density and layers of SiO₂ coating can be well controlled by tuning the assembly time and repeating the assembly process. With such a versatile strategy, the enhancement effects of SiO₂ coating on textured silicon solar cells were systematically examined by varying assembly conditions. It was found that the close-packed SiO₂ monolayer yielded a maximum relative efficiency enhancement of 9.35%. Combining simulation and macro/micro optical measurements, we attributed the enhancement to the nanosphere-induced concentration and anti-reflection of incident light. The proposed self-assembly strategy provides a facile and cost-effective approach for engineering nanomaterials at 3D interfaces.

Ultrasonic Interfacial Engineering of Red Phosphorous-Metal for Eradicating MRSA Infection Effectively

Sonodynamic therapy (SDT) is considered to be a potential treatment for various diseases including cancers and bacterial infections due to its deep penetration ability and biosafety, but its SDT efficiency is limited by the hypoxia environment of deep tissues. This study proposes creating a potential solution, sonothermal therapy, by developing the ultrasonic interfacial engineering of metal-red phosphorus (RP), which has an obviously improved sonothermal ability of more than 20 °C elevation under 25 min of continuous ultrasound (US) excitation as compared to metal alone. The underlying mechanism is that the mechanical energy of the US activates the motion of the interfacial electrons. US-induced electron motion in the RP can efficiently transfer the US energy into phonons in the forms of heat and lattice vibrations, resulting in a stronger US absorption of metal-RP. Unlike the nonspecific heating of the cavitation effect induced by US, titanium-RP can be heated in situ when the US penetrates through 2.5 cm of pork tissue. In addition, through a sonothermal treatment in vivo, bone infection induced by multidrug-resistant Staphylococcus aureus (MRSA) is successfully eliminated in under 20 min of US without tissue damage. This work provides a new strategy for combating MRSA by strong sonothermal therapy through US interfacial engineering.

Nanosized concave pit/convex dot microarray for immunomodulatory osteogenesis and angiogenesis

The immunomodulatory capability of biomaterials is of paramount importance for successful material-mediated bone regeneration. Particularly, the design of surface nano-topography can be leveraged to instruct immune reactions, yet the understanding of such "nano-morphology effect" is still very limited. Herein, highly ordered nano-concave pit (denoted as NCPit) and nano-convex dot (denoted as NCDot) microarrays with two different sizes were successfully constructed on a 316LSS surface via anodization and subsequently immersion-coating treatment, respectively. We, for the first time, comparatively investigated the interactions of NCPit and NCDot microarrays with RAW264.7 macrophages and their immunomodulatory impacts on osteogenesis and angiogenesis of human bone mesenchymal stem cells (hBMSCs) and human umbilical vein endothelial cells (HUVECs). NCDot microarrays induced macrophages towards M2 polarization with the higher expression level of anti-inflammatory markers (IL-10 and CD 206) and the lower level of pro-inflammatory markers (TNF-α, IL-1β, IL-6 and CD 86) than those of the corresponding NCPit microarrays. During the process, the expressions of osteogenesis-related genes (Runx2, OPN and OCN) of hBMSCs, and angiogenesis-related genes (eNOS, HIF-1α, KDR and VEGF) of HUVECs were significantly upregulated by the NCDot microarray-modulating immune microenvironment of macrophages, and finally stimulated osteogenesis and angiogenesis. Thus, the prepared NCDot arrays were able to significantly promote osteo-/angiogenic activity by generating a more suitable immune microenvironment than NCPit arrays, offering substantial evidence for designing immunomodulatory biomaterials with specific microstructures and optimal bioactivity.