Synergistic Reinforcing Mechanisms in Cellulose Nanofibrils Composite Hydrogels: Interfacial Dynamics, Energy Dissipation, and Damage Resistance

Engineering reversible cross-links between nanoparticles and polymer matrix is a promising avenue to reinforce the mechanical properties of elastomers and in particular soft hydrogels. In this work, we study a model system of composite hydrogel reinforced with cellulose nanofibrils (CNFs), where the integration of reversible hydrogen bonds into a lightly covalently cross-linked polyacrylamide (PAAm) matrix. This approach yields the dual cross-linked networks with synergistically improved strength, modulus, and toughness. The reversible nature of the hydrogen-bonded cross-links manifests a strong strain rate (έ) dependent dynamics properties. The CNF-PAAm interaction among physically adsorbed chains on the surface of CNF is examined as a function of CNF fraction by sum frequency generation spectroscopy. The results indicate a decrease of the number of free −OH groups on the CNF surface. Moreover, the deformation-resting experiments show a unique interface stiffening mechanism where the polymer chains desorbed from the CNF surface under oscillatory shear become entangled during resting time. The bending micromechanics test reveals that the CNF interfacial slip imparts the capability to strengthen the composites during deformation. The fibril pull-out process activates a series of dissipation mechanisms that increase the crack propagation resistance. These findings advance our understanding the role of interfacial layer in microscopic reinforcement mechanism and provide a constitutive foundation for exploring the deformation behaviors of the cellulosic hydrogels

Simulation codes for PDE and generalised Landau– Levich equation

Simulation codes for PDE and generalised Landau– Levich equatio

An Anionic Heptacopper(II) Oxo-Cluster {Cu^II₇} with an <i>S</i> = 7/2 Ground State

An anionic heptacopper­(II) oxo-cluster {Cu₇} was obtained from a simple reaction in aqueous solution without heating. In a similar reaction, another cage compound {Sb₁₂} with an encapsulated {Cu₂} core was produced, implying the structural versatility of copper­(II)-oxide assemblies constructed from potassium antimonyl tartrate as the ligand in aqueous solution. The ferromagnetic <i>S</i> = 7/2 ground state of {Cu₇} is confirmed by magnetization measurements

Enantiomerically Pure Chiral {Cu^II₃₂}‑Based 2D-Layered Frameworks: From the Asymmetric Octacopper(II) Subcomponents to 3D Hierarchical Supramolecular Structures

Two new chiral copper­(II) coordination polymers comprising octacopper­(II) subcomponents were synthesized through investigation of the interplay among tartrate ligands, guanidinium cations, and metals. Our analysis confirms that these compounds are enantiomers exhibiting 3D hierarchical supramolecular structures that are constituted by 2D sublayers and sustained by noncovalent bonding interactions

Discovery of components in honeysuckle for treating COVID-19 and diabetes based on molecular docking, network analysis and experimental validation

Molecular docking screening identified ochnaflavone, madreselvin B and hydnocarpin as key components for treating COVID-19 with diabetes in honeysuckle using 3 C-like protease (Mpro), angiotensin-converting enzyme 2 (ACE2), and dipeptidyl peptidase 4 (DPP4) as molecular docking targets, ACE2, DPP4, IL2, NFKB1, PLG, TBK1, TLR4 and TNF were the core targets, and multiple antiviral and anti-inflammatory signalling pathways were involved. Further, the levels of IL-1β and DPP4 in cell supernatant that had been activated by LPS was decreased by hypnocarpin, and ACE2 protein and DPP4 mRNA in cells were down-regulated. Overall, we have identified three components from honeysuckle that have potency to treat COVID-19 combined with diabetes. SARS-CoV-2 transcription may be inhibited by these components in honeysuckle, reducing virus invasion, inhibiting inflammatory factors, and improving immune response. Our findings could provide a basis for the clinical application and further development of honeysuckle.</p

Model estimate results.

<p>Model estimate results.</p

Bottom-Up Self-Assembly of the Sphere-Shaped Icosametallic Oxo Clusters {Cu₂₀} and {Cu₁₂Zn₈}

A discrete nanospheric icosametallic cluster comprised of 20 Cu ions (<b>1</b>) was self-assembled from facile synthesis. Adjustment of the synthesis by the choice of ligands gave rise to another cluster (<b>2</b>) with an intact icosacupric core and improved stability. Referring to the synthesis of <b>1</b> and <b>2</b>, a heterometallic cluster (<b>3</b>), which contains 12 Cu^II and 8 Zn^II, was designed and characterized by single-crystal X-ray diffraction, combined with elemental analysis, energy-dispersive X-ray, X-ray photoelectron spectroscopy, thermogravimetric analysis, and element mapping. The magnetic measurements of <b>2</b> and <b>3</b> and the scanning electron microscopy images and UV–visible diffuse-reflectance measurements of metal oxides from <b>2</b> and <b>3</b> indicate that isolation of {Cu₁₂M₈} is a new synthetic route to materials with engineered properties

2013 regional PM_2.5 concentration trends.

<p>2013 regional PM_2.5 concentration trends.</p

Bottom-Up Self-Assembly of the Sphere-Shaped Icosametallic Oxo Clusters {Cu₂₀} and {Cu₁₂Zn₈}

A discrete nanospheric icosametallic cluster comprised of 20 Cu ions (<b>1</b>) was self-assembled from facile synthesis. Adjustment of the synthesis by the choice of ligands gave rise to another cluster (<b>2</b>) with an intact icosacupric core and improved stability. Referring to the synthesis of <b>1</b> and <b>2</b>, a heterometallic cluster (<b>3</b>), which contains 12 Cu^II and 8 Zn^II, was designed and characterized by single-crystal X-ray diffraction, combined with elemental analysis, energy-dispersive X-ray, X-ray photoelectron spectroscopy, thermogravimetric analysis, and element mapping. The magnetic measurements of <b>2</b> and <b>3</b> and the scanning electron microscopy images and UV–visible diffuse-reflectance measurements of metal oxides from <b>2</b> and <b>3</b> indicate that isolation of {Cu₁₂M₈} is a new synthetic route to materials with engineered properties

Bottom-Up Self-Assembly of the Sphere-Shaped Icosametallic Oxo Clusters {Cu₂₀} and {Cu₁₂Zn₈}

A discrete nanospheric icosametallic cluster comprised of 20 Cu ions (<b>1</b>) was self-assembled from facile synthesis. Adjustment of the synthesis by the choice of ligands gave rise to another cluster (<b>2</b>) with an intact icosacupric core and improved stability. Referring to the synthesis of <b>1</b> and <b>2</b>, a heterometallic cluster (<b>3</b>), which contains 12 Cu^II and 8 Zn^II, was designed and characterized by single-crystal X-ray diffraction, combined with elemental analysis, energy-dispersive X-ray, X-ray photoelectron spectroscopy, thermogravimetric analysis, and element mapping. The magnetic measurements of <b>2</b> and <b>3</b> and the scanning electron microscopy images and UV–visible diffuse-reflectance measurements of metal oxides from <b>2</b> and <b>3</b> indicate that isolation of {Cu₁₂M₈} is a new synthetic route to materials with engineered properties