GIANT最新文献

The emerging interests in high-performance biocomposites grows significantly driven by their superior environmental sustainability. This study proposes a unique biocomposite strategy by implementing an acetic and ball-milled treatment to disrupt the bamboo cell wall structure, thereby facilitating further processing by effectively increasing the active sites and specific surface area in the bamboo fiber. The fibers are subsequently carboxymethylated to introduce carboxyl groups which facilitate physical bonding between the fibers and Mg²⁺ ions that are added to the system. These ions form metal-coordination bonds with the carboxyl groups, acting as ion bridges that significantly strengthen the inter-fiber bonding. The resulted biocomposite exhibits impressive mechanical properties, including a high tensile strength (94.24 MPa) and flexural strength (104.14 MPa), not only that, changes in elastic modulus also highlight changes in fiber bonding, the flexural modulus is 21.29 GPa and the tensile modulus is 7.01 GPa. Moreover, it maintains a low water uptake capacity of only 6.8 % despite being submerged for 12 h. The thermal conductivity and fire retardancy have also been improved. The synergic bonding ability between the cellulose and lignin in the fibers, coupled with the glue-free thermoforming process, enhances the material performance and renders it fully recyclable, thus reducing environmental pollution and providing cost-effective engineering materials to society.

Synthetic chemistry has played a vital role in miscellaneous fields of human civilization over the past century. The synthetic stage yet remains time-consuming and labor-intensive. To overcome these limitations, automation has been introduced to transform synthetic chemistry, leading to the development of high-throughput methods for molecular discovery. Automated flow chemical synthesis (AFCS) has recently emerged as a promising candidate, offering improved efficiency, scalability, and sustainability over the well-known automated solid-phase peptide synthesis. To further advance AFCS, elements like artificial intelligence-based computer-aided structure design and synthesis planning, autonomously assembled compatible synthesis with enhanced automated process control, and autonomous optimization can be considered. This review focuses on recent advances in computer-aided automated flow chemical synthesis (CAAFCS) of polymers in living polymerization and iterative synthesis strategy. The current challenges and outlook are finally discussed for developing more powerful CAAFCS systems and expanding their applicability across numerous fields, potentially providing brand-new perspectives and guidelines for future developments in this field.

Biomass conversion is pivotal in promoting sustainability and mitigating environmental pollution. In the quest to address the daunting challenge of oil spills, bioaerogels have surfaced as a beacon of hope. Their unique attributes, including remarkable porosity, lightness, and eco-compatibility, position them as ideal candidates for this purpose. Nonetheless, their application is not without challenges. Key issues such as limited capacity for oil absorption, specificity in oil-water separation, mechanical robustness, stability, and control over buoyancy are areas of active research and development. This comprehensive review delves into the current trends and advancements in augmenting the efficacy of bioaerogel composites specifically tailored for oil spill remediation. It meticulously examines a spectrum of modification strategies. Through a detailed analysis of recent research and technological breakthroughs, the review sheds light on innovative approaches and methodologies. It underscores the potential of these advancements in elevating the performance of bioaerogel composites in the realm of oil spill management. The insights gathered here are instrumental in charting the course for future research directions. They also underscore the importance of interdisciplinary collaboration in tackling environmental crises.

The treatment of diabetic wounds is a major challenge faced by the medical system, and there is a growing interest in developing innovative therapies to accelerate wound healing. Regenerative medicine with cells has shown promising potential in skin repair, with the regenerative properties primarily attributed to the paracrine effects of secreted products, including exosomes. Compared to cell-based approaches, using exosomes as a cell-free therapy for chronic wounds has several advantages. Exosomes can regulate intercellular communication by releasing their contents, including mRNA, miRNA, lipids, and proteins, which further promote wound healing. Exosomes are well explored in biomedical application owing to their advantages such as their biocompatibility and low immunogenicity. However, the common method of exosome administration is through injection, but due to their rapid clearance rate in the body, maintaining the necessary therapeutic concentration around the wound is challenging. Therefore, it is necessary to develop a new biocompatible scaffold as a carrier for extracellular vesicles, allowing them to sustain the therapeutic concentration at chronic non-healing wound sites and continuously promote wound healing. Engineered exosomes are kinds of exosomes modified with internal treated molecules, surface decoration or delivered through engineered platform. In addition, some researchers have further processed and modified exosomes, known as engineered exosomes, with internal treated molecules, surface decoration, or delivery through engineered platforms. Compared to regular exosomes, engineered exosomes have greater advantages in promoting wound healing. In this review, we summarize the molecular mechanisms of exosomes from different sources with varying modifications in wound healing. Advantages and limitations of different engineered exosomes for chronic wound repair were also discussed. Finally, we highlight the challenges and future development directions for translating our knowledge of engineered exosomes into clinical practice.

We report on the Matrix Assisted Pulsed Laser Evaporation, laser technology for depositing biocompatible, antimicrobial, hydrophilic, and biodegradable complex hybrid polymeric system loaded with essential cypress-oil and magnetite nanoparticles as resorbable implants, capable of targeting possible hyperthermia applications, an anticancer moderate field heating therapy. Magnetite nanoparticles based on iron oxide (Fe₃O₄) coated with Cypress essential oil (denoted: Fe₃O₄- Cypress) and embedded in PLGA (poly(lactic-co-glycolic acid) (denoted: PLGA-Fe₃O₄- Cypress-) and PLGA - poly(3,4-ethylene dioxythiophene) doped with poly(styrene sulfonate) anions) (PEDOT: PSS) mixture (denoted: PLGA-Fe₃O₄- Cypress- PEDOT: PSS) were used as MAPLE targets. The controlled drug delivery of the active Cypress oil, an antimicrobial therapeutic agent from Fe₃O₄- Cypress nanoparticles could be possible by applying an external radio frequency (RF) magnetic field. The Fe₃O₄-Cypress-based powders as well as the final hybrid coatings have been characterized in terms of stoichiometry, morphology, magnetic, antimicrobial properties, biocompatibility, and response to external physical stimuli. FTIR analyses confirmed the quasi-stoichiometric laser transfer of organic compounds while the XRD evidenced the semicrystalline structure of deposited thin films. SEM and AFM images evidence that conductive polymer addition led to the films' relief flattening and a decrease in the coatings' thickness and roughness by changing the polymeric packaging. The samples containing conductive polymer exhibited 3 times higher current and corrosion rate values. All coatings are hydrophilic and revealed enhanced cellular viability when cultured with osteoblast-like MG-63 cells. The composite structures exhibited significant antimicrobial activity against Gram-positive (Staphylococcus aureus), and Gram-negative (Escherichia coli) bacteria, as well as to the opportunistic yeast Candida albicans.

Understanding the structure-property relationship is of paramount importance for tailoring copolymers for specific applications. Poly(N-acryloylmorpholine)-block-poly(N-isopropylacrylamide) (PNAM-b-PNIPAM) diblock copolymers were synthesized by reversible addition–fragmentation chain transfer (RAFT) polymerization with varying M_n and composition, providing the basis for deducing structure-property relationships. The chemical structure of the copolymers was analyzed by mass spectrometry (MS). A novel and efficient mass spectrum processing methodology was developed for the detailed analysis of polymers/copolymers that greatly expands the upper mass limit of the time-of-flight (TOF) analyzers in the linear mode up to 20,000 Da. Our method “makes visible” the mass peaks of the individual copolymer species and their isotopologues providing effective and fast automatized analysis. The self-assembly property of the thermoresponsive PNAM-b-PNIPAM diblocks in aqueous solutions was investigated by dynamic light scattering (DLS) experiments, and quantified by determining the incipient temperature of the phase transition. For rapid evaluation, an artificial neural network (ANN) was created to explore the hidden relationships between the structural information obtained by our novel mass analysis method and the properties as well as to predict the self-assembly behavior of the copolymers.

Cellulose from biomass is an abundant and renewable alternative source for chemicals and fuels, yet its utilization by chemical or biological process requires pre-treatment in order to release the macromolecules from their tightly packed crystal structure. Phosphoric acid (PA) has been known for many years to be an efficient solvent for crystalline cellulose. It is also established that a certain quantity of water content in PA is required for efficient pretreatment. This study uses small-angle neutron scattering (SANS) measurements to evaluate cellulose dissolution in deuterated phosphoric acid (dPA), at different wt% dPA between 78 and 97 % (different D₂O content). The SANS method is useful for this purpose due to the availability of deuterated dPA, its contrast in scattering length density towards cellulose, and its low incoherent scattering cross-section. The results indicate that most of the cellulose in 2 wt% solution is dissolved in PA as individual chains, at acid content of 81–94 wt% PA. Structural differences of the dissolved cellulose in PA of the various water compositions in this range are insignificant. At 78 % dPA the cellulose crystal still seem to be disrupted, yet the structure can be modeled as mass-surface fractals of small fibrils with irregular surface, possibly due to dissolved chain segments, which are aggregated as mass fractals of rods. At 97 % dPA evidence for a small content of undissolved fibrils is noted.

Colorful cholesteric liquid crystal polymer network (CLCN) patterns can be applied for decoration and anti-counterfeiting. Herein, the CLC inks were prepared using an acrylate liquid crystal, chiral dopants and a photoinitiator. Full-color CLCN patterns were able to be printed out using only two CLC inks by changing their volume ratio. A structure with a gradient helical pitch was identified between different colors. For anti-counterfeiting, the color patterns composed of opposite-handed CLCNs were also printed. A helical-nonhelical-helical structure was identified at the interface. In addition, CLCN patterns with a grating structure were also prepared. The results shown here not only give us a better understanding the cholesteric structure, but also lay the foundations for the applications of CLCN patterns in the fields of decoration and anti-counterfeiting.

Hydrogel is widely employed in flexible electronics and soft robotics as soft mechanical material. Previous reports exploited the swelling properties of hydrogel to achieve large negative deformations, but few reports exhibit multiple deformation modes. This paper designs two-dimensional metamaterials that convert hydrogel swelling deformation into bending deformation, including positive/negative swelling, isotropic/anisotropic, and gradient/bending deformation modes. The regulation of hydrogel swelling on the negative expansion deformation of metamaterials is explored through the theoretical model and finite element analysis. The corresponding relationship between the microstructure deformation and the band gap change during the hydration process is obtained. Inspired by kirigami, we proposed a self-assembly model with substrate expansion-driven three-dimensional microstructure. The results show that the deformation modes of metamaterials may be interconverted through structural design. The band gap can be tuned by swelling deformation.