GIANT最新文献

Sugar-based block co-oligomer (BCO) consisting of saccharide block exhibits high segregation strength that overcomes the limitation of the traditional block copolymers for accessing the ordered nanostructures with ultrasmall feature size. This study explores the influence of molecular chirality on the self-assembly behavior of glucose-block-tocopherol (Glc-b-Toc) BCOs, wherein the Toc blocks were either pure in chirality or being a mixture of the stereoisomers. Both the chiral and racemic BCOs formed a hexagonal perforated layer (HPL) structure with an unusually small aspect ratio (c/a) of the unit cell, attributable to the propensity of the Glc block to enhance hydrogen bonding formation. As the temperature was increased, the dominance of hydrogen bonding interactions diminished, resulting in a gradual increase in the c/a ratio and eventually a transformation of the HPL structure to a double gyroid (DG) phase. The chirality of the Toc block enhanced the effective segregation strength of the BCO, leading to elevated order-order transition temperatures associated with the HPL-to-DG and DG-to-hexagonally packed cylinder (HEX) transitions. Within the HPL phase window, the chiral BCO exhibited significantly slower kinetics during thermally-induced structural reorganization in adjusting the c/a ratio, especially in the cooling process. Consequently, a pronounced hysteresis in the structural reorganization of the chiral BCO was observed. This phenomenon was ascribed to the chiral interaction between the Toc blocks, which limited the diffusion of the BCO molecules for the structural reorganization.

Despite the excellent lubricity of conventional hydrogel materials due to their wet-soft properties, they produce severe mechanical elastic deformation at higher interfacial contact stresses. Balancing the load-bearing capacity and lubricating properties of hydrogel material is the difficulty of the current research work for articular cartilage substitutes. Great progress has been made in developing bionic joint materials with high load-bearing and low-friction hydrogels based on gradient designs. However, most bionic materials are based on sliding friction greatly limiting the improvement of lubrication performance. Herein, we designed and prepared a new hydrogel material with high load-bearing capacity and stable lubrication performance, breaking through the traditional friction method and turning to “sliding” for “rolling”. The network on the hydrogel surface was dissociated by UV irradiation and the pores on the surface were filled with SiO₂ nanoparticles. The dense network structure of the underlying layer endows the hydrogel material with good load-bearing properties, while the high degree of hydration of the surface layer and the rolling friction effect of SiO₂ nanoparticles greatly enhance the lubrication property. With the synergistic effect of these designs, the multi-layered hydrogel with nanoparticles on the surface achieved an ultra-low average coefficient of friction (COF) of ∼0.00809 at a high load of 50 N during 30,000 cycles. This idea of hydrogel material design provides a new strategy for the replacement of biomimetic articular cartilage materials.

Inspired by the extracellular matrix (ECM), biomaterials have emerged as promising strategies in the biomedical research and engineering domain, offering unique characteristics for tissue regeneration, drug delivery, therapeutic interventions, and cellular investigations. The ECM, a dynamic network structure secreted by various cells, primarily comprises diverse proteins capable of facilitating tissue-ECM signaling and regulatory functions through its rich array of bioactive substances and multi-level structural properties. Drawing inspiration from the intricate structure and biochemical composition of natural ECM, researchers have developed various biomaterials to encapsulate these features and create biomimetic microenvironments, such as electrospinning, hydrogels/hydrogel microspheres, decellularized ECM(dECM), and ECM-mimicking peptides. Furthermore, by mimicking the structural composition of ECM components, ECM-inspired biomaterials exhibit varying degrees of ECM functionalization, including providing structural support, cell adhesion, signal transduction, mitigating immune responses, and tissue remodeling. In summary, the advancements in ECM-inspired biomaterials offer significant promise in addressing key challenges in the fields of tissue engineering, regenerative medicine, and drug delivery.

Organic photodetectors (OPDs) own unique advantages such as light weight, flexibility, low production cost, tunable detection wavelength, and thus are promising for a variety of applications. The lack of hole-blocking layer (HBL) materials impedes the reduction of dark current density and the enhancement of the performance of OPDs. Herein, we employed an n-type polythiophene n-PT1 as a HBL material for inverted OPDs. The specific solubility of n-PT1 in o-dichlorobenzene facilitates solution processing and enables multilayer device fabrication. The ultradeep-lying highest occupied molecular orbital energy level ensures a large hole injection barrier between cathode and active layer that suppresses dark current. As a result, compared to the control devices without n-PT1, the inverted OPD devices with n-PT1 as HBL demonstrate a two-order-of-magnitude reduction in dark current density and a one-order-of-magnitude increase in specific detectivity. To the best of our knowledge, this is the first solution processable HBL material for inverted OPDs.

The field of bone regeneration has witnessed significant advancements with the exploration and incorporation of marine biomaterials, offering promising avenues for orthopaedic and dental applications. Marine environments are a rich source of biological materials with unique properties conducive to bone healing and regeneration. Repurposing and reusing some waste by-products of marine products for bone regeneration not only contribute to environmental protection but also drives the development of the marine economy, thereby achieving sustainable development. Moreover, the lower production costs associated with the abundant availability and easy processing of marine biomaterials make bone regeneration therapies more accessible to a broader population, enhancing global health equity. By exploring the current research progressions on marine biomaterials and recounting their sources, properties, mechanisms of action, and applications in bone regeneration research, this review provides a comprehensive overview of the potential and challenges of marine biomaterials for future bone healing and regeneration applications.

Wound healing requires a contamination-free, sterile, and breathable environment. However, to develop an ideal wound dressing with all these functionalities simultaneously poses significant challenges. In this study, we designed a wound dressing that mimics the structure of skin with good breathability and protective functions. The wound dressing consists of a hydrophilic Poly(3-hydroxybutyrate-co-4-hydroxybutyrate) (P34HB) membrane coated with zinc oxide nanoparticles and a hydrophobic polyvinylidene fluoride (PVDF) membrane. Meanwhile, plasma treatment was also utilized to bond the two layers, resulting in an enhancement of 60 % in mechanical properties. The crosslinked fibrous membranes exhibited uniform stress distribution when stretching. Due to the unique structures of the wound dressing, it demonstrates wound exudate management, antibacterial functions, and hemostatic properties. The hydrophobic layer guided wound exudate towards the hydrophilic layer and the zinc oxide nanoparticles acted as a barrier against external bacteria and released zinc ions to inhibit bacterial growth in the exudate. Moreover, the water vapor transmission rate (WVTR) was measured to be over 86.55 kg/m²/day, the hemolysis rate was 2.38 %, and an impressive 81.98 % healing rate was recorded during in vitro wound healing. This skin-mimicking wound dressing shows great potential as a promising solution for the therapy of chronic wounds and infections.

Side-chain modification and asymmetric design for non-fullerene acceptors (NFAs) have been proven to be effective methods for harvesting high-performance organic solar cells (OSCs). Combining the two molecular design strategies, we adopted phenyl chain and alkyl chains with different shapes to develop two novel asymmetric NFAs, named BTP-P2EHC11 and BTP-P2EHC2C4. Compared with BTP-P2EHC2C4 attached 2-ethylhexyl side chain, BTP-P2EHC11 with linear alkyl side chain have slightly red-shifted absorption and intensive absorption strength. Moreover, the PM6:BTP-P2EHC11 blend film presents higher and more balanced charge mobilities, reducing charge recombination, tighter intermolecular packing and more favorable fibrous network morphology with appropriate phase separation than PM6:BTP-P2EHC2C4, which lead to significantly enhanced short-circuit current density (J_SC) of PM6:BTP-P2EHC11-based devices. Thus, the OSCs based on PM6:BTP-P2EHC11 achieve a superior power conversion efficiency (PCE) of 18.50% with a good trade-off among open-circuit voltage (V_OC) of 0.876 V, J_SC of 26.85 mA cm⁻² and fill factor (FF) of 78.65%, while PM6:BTP-P2EHC2C4-based device exhibits a lower PCE of 17.49%. Our investigation elucidates that the combination of finely optimizing the shape of alkyl-chain and asymmetric side groups of NFAs could pave a promising avenue toward morphology optimization and performance promotion of OSCs.

Ferroelectric nematic liquid crystals exhibit unique non-linear optical properties, with the potential to become transformative materials for photonic applications. A promising direction relies on the fabrication of tailored polar orientational patterns via photoalignment, thus shaping the non-linear optical susceptibility through thin slabs of the ferroelectric fluid. Here, we explore the fabrication of 2D periodic SHG active arrays in ferroelectric nematic fluids, for different materials, cell thicknesses and motifs. Based on polarizing optical microscopy observations in combination with optical simulations, second harmonic generation microscopy and interferometry, the 3D structure of the motifs is revealed. Two different 2D periodic patterns are explored, showing that the balance between flexoelectric and electrostatic energy can lead to different domain structures, an effect which is rooted in the difference between the flexoelectric properties of the materials. It is shown that by combining the surface-inscribed alignment with different spontaneous degrees of twist, 2D SHG active arrays can be obtained in the micrometre scale, in which adjacent areas exhibit maximum SHG signals at opposite angles.

The global community has encountered numerous challenges concerning environmental sustainability, encompassing issues like waste generation, depletion of natural resources, air pollution, and other threats to human well-being. Consequently, the pursuit of an eco-friendly environment has emerged as a critical concern in recent years. Polysaccharides, being natural biopolymers, have garnered significant attention owing to their distinctive properties that make them versatile for various applications. Numerous sustainable and environmentally friendly polysaccharides, such as chitosan, cellulose, starch, hyaluronic acid, alginate, and inulin, have been identified. This article highlights the characteristics of renewable polysaccharides, their categorization, and their potential to contribute to environmental sustainability. It introduces environmentally friendly extraction methods aimed at minimizing chemical pollution. Through the careful selection of diverse polysaccharides and the application of functionalization techniques, the article suggests the possibility of obtaining suitable superabsorbent hydrogels, appropriate nanocomposites, and effective scaffolds. The significance of utilizing polysaccharide-based materials is explored in detail, emphasizing their exceptional properties. Additionally, the article discusses the various applications of eco-friendly polysaccharides as sustainable polymers, including in agriculture, biomedicine, and food packaging.

The thin film morphology of double-cable conjugated polymers is critical to the performance of single-component organic solar cells (SCOSCs). Here, we explore the effect of thin film crystallinity on device performance by varying the thermal annealing temperature used during device fabrication. Our investigations reveal that a moderate annealing temperature of 150 °C optimizes the power conversion efficiency in SCOSCs. Although higher annealing temperatures leads to increased crystalline order, a decrease in device performance is observed, attributed to imbalanced carrier transport and increased charge recombination. Additionally, the progressive decrease in the open-circuit voltage of these cells with increasing annealing temperature is linked to augmented non-radiative voltage losses, stemming from the increase in film crystallinity. This study underscores the critical necessity of achieving a delicate optimization of film microstructure in order to maximize the efficiency of SCOSCs, while also delineating prospective avenues for refining the molecular design and processing of double-cable polymers to bolster solar cell performance.