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We present a liquid-crystal laser device based on the chiral ferroelectric nematic phase (N_F*). The laser medium is obtained by mixing a ferroelectric nematic material with a chiral agent and a small proportion of a fluorescent dye. Notably, in the N_F* phase very low electric fields perpendicular to the helical axis are able to reorient the molecules, giving rise to a periodic structure whose director profile is not single harmonic but contains the contribution of various Fourier components. This feature induces the appearance of several photonic bandgaps whose spectral ranges depend on the field, which can be exploited to build tunable laser devices. Here we report the characterization of home-made N_F* lasers that can be tunable under low electric fields and present laser action in two of the photonic bands of the material. The obtained results open a promising route for the design of new and more versatile liquid-crystal based lasers.

A surface in contact with the isotropic phase of a passive liquid crystal can induce nematic order over distances that range from microscopic to macroscopic when the nematic-isotropic interface undergoes an orientational-wetting transition. If the nematic is active, what happens to the interface? Does it propagate and, if it does, is its structure different from the passive one? In this paper, we address these questions. We investigate how the active nematic-isotropic interface is affected by the anchoring strength of the surface, the bulk ordering field and the activity. We find that while passive interfaces are one-dimensional the active ones exhibit two dynamical regimes: a passive-like regime and a propagating regime where the interfaces propagate until the entire domain is active nematic. Active interfaces break the translational symmetry within the interfacial plane above a threshold activity, where the active nematic fluctuations, which are ultimately responsible for the emergence of an active turbulent nematic phase, drive non-steady dynamical interfacial regimes.

Biomaterials that can be reversibly stiffened and shaped could be useful in broad biomedical applications where form-fitting scaffolds are needed. Here we investigate the combination of strong non-linear elasticity in biopolymer networks with the reconfigurability of packed hydrogel particles within a composite biomaterial. By packing microgels into collagen-1 networks and characterizing their linear and non-linear material properties, we empirically determine a scaling relationship that describes the synergistic dependence of the material's linear elastic shear modulus on the concentration of both components. We perform high-strain rheological tests and find that the materials strain stiffen and also exhibit a form of programmability, where no applied stress is required to maintain stiffened states of deformation after large strains are applied. We demonstrate that this non-linear rheological behavior can be used to shape samples that do not spontaneously relax large-scale bends, holding their deformed shapes for days. Detailed analysis of the frequency-dependent rheology reveals an unexpected connection to the rheology of living cells, where models of soft glasses capture their low-frequency behaviors and polymer elasticity models capture their high-frequency behaviors.

Herein, we demonstrate a simple approach to control the orientation of cylinder-forming nanostructures in polystyrene-block-poly(L-lactide) (PS-b-PLLA) BCP thin films through thermal annealing under a high-vacuum environment. Surface tension discrepancy between the constituent blocks is critical in controlling the aimed orientation of self-assembled nanostructures in block copolymer (BCP) thin films. For BCP self-assembly, temperature has been widely utilized as a thermodynamic state variable under ambient pressure conditions, whereas the use of high vacuum (low pressure) for thermal annealing is limited. It has been observed that temperature can alter the surface tension only marginally with increasing temperature for polymeric materials; as a result, the pressure dependence of surface tension for PS and PLLA was investigated. By increasing the vacuum degree during thermal annealing, the surface tension discrepancy between the PS and PLLA blocks can be reduced significantly. Accordingly, during thermal annealing under high vacuum degree, a neutral air polymer interface can be generated for the BCP thin films, resulting in the formation of perpendicular cylinders from the neutral surface of the thin film through BCP microphase separation.

In this work, for the first time, films were obtained based on biodegradable polyhydroxyalkanoates (PHAs) - a copolymer of 3-hydroxybutyrate-co-3-hydroxyvalerate P(3HB-co-3HV) and a copolymer of 3-hydroxybutyrate-co-4-hydroxybutyrate P(3HB-co-4HB), containing drugs of different chemical structure and action - antibiotics (ceftazidime, doripenem), antiseptic (chlorhexidine) and tissue regeneration stimulator (Actovegin) for drug delivery and cell culture. Using SEM, AFM and measuring the contact angles of water wetting, it is shown how PHAs composition and loading of films of P(3HB-co-3HV) and P(3HB-co-4HB) with drugs affect the porosity, roughness indicators and adhesive properties of the surface. The constructed films are a depot form of drug, the release of which in vitro is realized for a long time, without burst releases, corresponds to Korsmeyer-Peppas and Higuchi models with diffusion character. Films loaded with antibiotics have pronounced antibacterial activity and suppress the development of pathogens S. aureus and E. coli, without a pronounced negative effect on the adhesion and proliferation of epidermal cells. In the cultures of human keratinocytes HaCaT it was shown that the presence of actovegin, as well as ceftazidime in the films, exhibits a stimulating effect, increasing their number. The results demonstrate the suitability of the depot-films for cellular technologies and are promising for the reconstruction of tissues complicated by infection.

This study investigates the development of sustainable multifunctional foams utilizing hemp stalk waste, lignin, xylan, pectin, glycerol, and citric acid. Using the freeze-drying method for foam formation in combination with industrial waste products and renewable resources, we emphasize a green, scalable material development approach. In total, 25 distinct formulations were prepared and methodically examined, mainly focusing on the roles of citric acid, pectin, and glycerol. Thermal crosslinking, conducted at 140°C, was analyzed using FTIR, confirming the formation of ester bonds. The microstructural characterization of the foams revealed distinct variations from nanofibrillar to microfibrillar structures based on composition. The bulk density of the foams ranged from 13 to 152 mg/cm³, and porosity values varied from 97 % to 99 % for most of the compositions. Foams showed up to 50 g/g water, 51 g/g rapeseed oil, and 46 g/g kerosine absorption. Foam absorption capacity changes were examined through 10 iterative cycles in water, demonstrating that most compositions retained near-original absorption capacities. Adding glycerol conferred exceptional hydrophobic properties to the foam surfaces, as evidenced by water contact angles ranging between 140° and 150°. The thermal conductivity of foams ranged from 0.040 to 0.046 W/mK. The mechanical properties of foams were assessed using compression testing, which showed highly tunable structures ranging from soft to rigid. This study illustrates the broad applicability of these foams, emphasizing their utility in thermal insulation, filtration systems, and environmental cleanup, among other potential uses.

Polyolefins are the most produced and widely used polymeric materials. However, the chemically inert nature of polyolefins has led to severe environmental pollution, posing a threat to human sustenance and development. Managing and recycling polyolefin plastic waste is crucial for the transition from a linear to a sustainable circular economy. Catalytic chemical recycling includes traditional techniques like pyrolysis and photolysis, and innovative methods that introduce chemical cleavable bonds into the polyolefin chain for closed-loop recycling. Catalytic post-functionalization of post-consumer polyolefin materials is another strategy to tackle plastic waste, aiming to upgrade the materials’ utility and contribute to sustainability. Overall, developing catalytic methods for deconstructing and upcycling plastics is essential to encourage better reclamation practices and reduce the environmental impact of plastic waste.

Traditional impact-resistance materials relying on the combination of supporting materials and energy-dissipation elastomers can effectively reduce shock load, yet the sharp interface between two types of materials causes discontinuous stress transfer and cracking. Here, inspired by the squid beak, we report a type of high impact-resistance gradient elastomers with large-scale modulus gradient with about three orders of magnitude (modulus range of 7 × 10³ ∼ 7 × 10⁶ Pa) and high energy dissipation (loss factor > 0.6) over a wide temperature range by diffusively introducing stiff polymers in a highly damping elastomer with controlled mechanical properties. Under the action of an external force, our gradient elastomers exhibit soft-while-stiff attributes, combining cushioning and support. In drop hammer impact tests, our gradient materials can reduce impact strength by 80 %, significantly better than commercial protective gear. It is worth mentioning that the modulus of the bottom layer matches that of the tissues for better protection.

Silicon (Si) is a promising substitute for graphite anode due to the high theoretical specific capacity (4200 mAh g⁻¹). However, too large volume change exists during the lithiation/delithiation process. Composite anode, prepared by mixing Si with graphite, can realize higher specific capacity than graphite and much better cycle performance than Si anode. However, the capacity decay caused by pulverization of Si particles is still a great challenge. Here, a cross-linkable binder rich in nitrile, carboxyl and hydroxyl groups is designed for composite silicon-graphite (Si-C) anode. The nitrile and hydroxyl groups can be in situ cross-linked in the batteries through Ritter reaction. The cross-linked binder has excellent resilience and good adhesion to the active materials and current collector. The cycle performance of the cell with cross-linked binder is much better than the counterpart. Scanning electron microscopy results of the cycled Si-C anode show that the cross-linked binder can suppress the volume expansion and pulverization. Moreover, the investigation with X-ray photoelectronic spectrum and density function theory calculation demonstrate that the decomposition of ester solvent and LiPF₆ on Si anode has been mitigated and more stable SEI film is formed on the Si-C anode. Our strategy of in situ cross-linking binder in the batteries has provided a feasible way for designing the next generation of silicon-based anodes with higher specific capacity and longer cycling life.

Biomineralization plays an important role in various physiological activities in both nature and living organisms. Organisms regulate the crystal nucleation, crystal phase, and crystal growth kinetics of inorganic phases through organic regulation, forming minerals with multi-level order, thereby playing a role in biological support, protection, and metabolic regulation. Unlike general inorganic minerals, biominerals are subtly regulated by organic organisms (such as small organic molecules, peptides, proteins, nucleic acids) and complex environments, possessing biological characteristics and becoming a part of living organisms. It can be seen that the process of biomineralization is not only the process of manufacturing biomaterials, but also the process of using materials to regulate organisms themselves. The biomimetic strategy based on biomineralization can achieve a huge transformation from the biomimetic preparation of functional materials to the biomimetic composite of organisms and materials. In this review, we briefly introduce biomimetic structures inspired by nature itself, and emphasize the important role of the relationship between organisms and materials in the process of biomineralization. We also briefly explore biominerals and their mechanisms. At the same time, a series of functional materials (such as self-cleaning hydrophobic materials, artificial spider silk fibers, mother of pearl like composite materials, humidity responsive materials, and bioprinting materials) synthesized through biomimetic strategies inspired by biomanufacturing materials were systematically elucidated. And a brief discussion was given on the synthesis of new functional organisms using biomimetic strategies to regulate organisms, such as using functional materials to regulate biomimetic repair of hard tissues, using biomineralization strategies to coat vaccines to improve their thermal stability during transportation and drug delivery efficiency in vivo, and constructing functional biomimetic artificial organelles on demand. Finally, this article summarizes the current opportunities and challenges based on biomineralization, providing further feasible guidance for future material regulation of life.