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Near-infrared (NIR) light-responsive liquid crystal elastomers (LCEs) doped with organic small-molecule photothermal agents have garnered scientific attention. However, the challenge remains in designing and synthesizing mesogenic photothermal dyes with absorption wavelengths greater than 800 nm. In this research, we design a novel discotic mesogenic NIR absorbing dye, namely the nickel bis(dithiolene) complex YHD868, and prepare NIR-responsive LCE/YHD868 composite films. The discotic mesogenic molecule YHD868 possesses a columnar hexagonal mesophase and exhibits intense NIR absorption at 868 nm, with a photothermal conversion efficiency of about 27 % and a molar extinction coefficient of approximately 30000 M⁻¹·cm⁻¹. Due to the strong NIR absorption of YHD868, combined with its excellent photothermal stability, the LCE/YHD868 composite films exhibit remarkable photoresponse and mechanical properties. Even at a low doping concentration of 0.2 wt%, the composite film can achieve a tensile strength of 9.8 MPa and an elongation at break of 165 %. Under 880 nm NIR irradiation (3.3 W·cm⁻²), the film can complete reversible photo-induced shrinking deformation in just 2 s, with a shrinkage ratio of about 64 %. This work offers a new approach for the development of photo-responsive smart soft materials.

Electrophysiology and optogenetics are pivotal in neuroscience for probing and modulating neural activities, playing a vital role in unraveling the complexities of brain functionality. Despite their importance, the efficacy of existing devices is hampered by insufficient functional integration, pronounced foreign body reactions, and physical constraints that impede natural animal behaviors. Here, we develop a multifunctional, ultraflexible neural probe designed for simultaneous electrophysiological monitoring and optical neural modulation, along with mechanical properties that are conducive to flexibility and compliance. By integrating a wireless neural signal acquisition and stimulation circuit, we achieved wireless recording of brain signals in mice and wireless optogenetic control over their locomotor behavior. The multifunctional ultraflexible probe presented in this study holds substantial promise for closed-loop brain-machine interfaces and deepening our understanding of neural circuit functions. This innovative approach addresses the aforementioned limitations by a comprehensive solution for in vivo neural interrogation and manipulation, marking a significant advancement in the tools available for neuroscience research.

Plastics, accumulating globally as microplastics in living organisms, significantly contribute to environmental issues. Current materials like polylactic acid and commercial paper face limitations due to inadequate heat and water resistance, resulting in various practical inconveniences. This study reports a high-strength, water-resistant, recyclable, and naturally degradable pure cellulose food packaging material, which is crafted from bacterial cellulose (BC) and ethyl cellulose (EC) by a straightforward filtration and scratch coating process. The use of the EC ethanol solution eliminates the need for additional binders. Remarkably, the EC-BC pure cellulose material exhibits excellent mechanical properties (tensile strength of 195.3 ± 23.2 MPa), a stability in liquid environments (136.9 ± 24.2 MPa mechanical strength after 30 minutes of immersion in water), recyclability, natural degradability, cost-effectiveness, and non-toxicity. These attributes position binder-free hybrid designs, based on cellulose structures, as a promising solution to address environmental challenges arising from the extensive use of single-use plastics.

Development of H-bonding organo-catalysts with high catalytic activity and high degree of control is significantly important for the metal-free polyesters that are potentially suitable for biomedical usage. The concomitant use of base and commercially available thiourea generally suffered from prolonged reaction time and resulted in incomplete monomer conversion in some cases. Introducing one or more (thio)urea H-bonding donating arms to the parent thiourea has been proved to be an effective method for substantially increasing the activity of thiourea H-bonding donors. Consequently, we synthesized bis-thioureas derived from binaphthyl-amine bearing different substituents and investigated their catalytic performance in ROPs of lactide in this work. The density functional theory (DFT) calculations suggested that the “activated-thiourea” mode is more preferred for the bis(thiourea) containing binaphthyl-amine framework. The bis(thiourea)/base binary systems could effectively promote the LA polymerization using benzyl alcohol as initiator. The polymerization rates and the degree of control over the polymerization are highly dependent on the structures of the bis(thiourea) and base. Bis(thiourea)/1,5,7-triazabicyclo[4.4.0]dec‑5-ene pairs exhibited highest catalytic activity compared to other bis(thiourea)/base pairs, and the turnover frequency is high up to 1980 h^–1 at 75 °C. In addition, the bulky hindrance and axial chirality of the binaphthyl-amine framework could enable stereoselective ROP of rac-LA to produce isotactic-rich and crystalline PLAs at relatively low temperature (0 °C). Mechanistic studies indicated that both enantiomorphic site control (ESC) and chain end control (CEC) concurrently occurred in the rac-LA polymerization catalyzed by bis(thiourea)/base binary systems. This work will inspire future design of H-bonding donors with high catalytic performance.

Polylactide (PLA) is a promising biopolymer from renewable resources but its brittleness and poor gas barrier properties limit flexible packaging applications. Therefore, in this work PLA was blended with a biobased rubbery poly(pentamethylene furanoate) (PPeF), acting as a toughening agent, and a commercial epoxy-functionalized compatibilizer (i.e., Joncryl® ADR-4468) was added to improve the interfacial interaction. The effect of PPeF loading (1–30 wt %) on phase morphology, mechanical properties, oxygen permeability, and degradability in compost was characterized. All blends displayed a sea-island morphology with refined PPeF domains upon compatibilization. Incorporating PPeF induced major tensile ductility enhancements from 5 % strain at break for neat PLA up to 200 % for the blend with 30 wt % PPeF, accompanied by progressive stiffness and strength declines. Through the application of the essential work of fracture (EWF) approach on the prepared films, the specific essential work of fracture (w_e) was seen climbing from 6.2 to 40.0 kJ/m² with rising PPeF content, confirming its effectiveness as a toughness enhancer. PPeF contributed to increase the UV- and gas barrier properties of PLA. For example, the oxygen permeability dropped by 37 % for the blend with 30 wt % PPeF. Moreover, compost burial tests also revealed 26 % weight loss of PPeF after 60 days, proving its biodegradability. Hence, finely dispersed PPeF domains induced synergistic property improvements, making PLA/PPeF blends a promising sustainable option for flexible and biodegradable packaging.

Anchoring noble metal sites through photo-reduction is an effective way to modulate charge distribution on photocatalytic interfaces, thereby enhancing photocatalytic performance. The irradiation field on the exposed surfaces of photocatalysts has an important influence on the morphology and distribution of noble metal sites. However, non-uniform light field derived from the scattering effects of particle-form photocatalysts hinders the well-distributed photo-deposition of noble metal sites. To address this challenge, we proposed a photo-deposition method utilizing the optical fiber coated with photocatalysts. TiO₂ nanorod (NR) array was coated on the optical fiber to achieve a well-distributed irradiation filed across the NR array. This resulted in a concentration of the irradiation field primarily within the NR array, maintaining uniformly distributed light intensities throughout. Palladium (Pd) sites dominated by nanoclusters were well distributed on TiO₂ NR array utilizing a photo-reduction method. These Pd sites functioned as electron acceptors, facilitating the effective separation and transfer of photo-generated carriers. Consequently, an highly active photocatalytic reaction interface was constructed, demonstrating the accumulation of a substantial concentration of holes and their efficient conversion into hydroxyl radicals (·OH). Notably, hydroxyl radicals with a concentration of 62.6 μM could be generated within 14.4 min. The construction of this efficient photocatalytic interface offers an optimal platform for accelerating photocatalytic reactions and enhancing photocatalytic efficiency.

Ice-templating technology has recently attracted extensive attention to achieve programed structure-property relationships in porous soft matter scaffolds. However, there is a huge gap existed between theoretical understanding and practical applications of nucleation kinetics and growth of ice crystals in supercooled water. This paper establishes a nucleation kinetics model of crystal growth in supercooled water, for designing ice-templating soft matter scaffolds with programmable structure-property relationship. A phase transition model was firstly formulated to characterize liquid-liquid phase transition of supercooled water, based on a two-state model and free-volume theory. Effects of diffusion coefficient and density of the supercooled water on ice nucleation kinetics and crystal growth were investigated, based on the classic nucleation theory. Analytical results showed excellent agreement with experimental data, with correlation indices of R²=90.7 % for diffusion coefficients and R²=94.0 % for densities, respectively. The model predicted a nucleation rate of 31.7 m⁻³∙s⁻¹ at 200 K and peak nucleation rate and crystal growth rates appearing at 183 K and 227 K. Constitutive relationships among mechanical behaviors, ice nucleus radius, nucleation ratio, and crystallization growth rate, were developed for the ice-templating scaffolds, based on the affine model theory and verified with finite element analysis results (R²= 99.9 %) and experimental results (R² = 95.8 %). Finally, the prediction results using the proposed model were further verified using the experimental data reported in the literature. This study provides a new methodology to describe the nucleation kinetics and growth of ice crystals in supercooled water and programmable structure-property relationships in ice-templating soft matter scaffolds.

Plasma membranes not only serve as physical barriers to separate the cell or organelle from extracellular or intracellular environments, but also play important roles in many cellular processes, e.g., cell adhesion, cell migration, endocytosis as well as membrane budding, whose correct executions rely on locally highly curved membrane shaping. Mechanically, these membranes are soft fluid interfaces exhibiting extremely dynamic remodeling processes in response to mechanobiological stimulus from their surrounding complex intra/extra-membranous circumstances containing thermal fluctuations, protein binding, protein-protein interaction on the membrane surface forming protein superstructures and active cytoskeletal networks. Correlating these dynamic membrane shaping involving characteristic membrane mechanical properties with cellular functions is essential to improving fundamental understandings in cell physiology and cell biomechanics. The challenge here is to explicitly describe the dynamics of membrane remodeling under the complex biological situations. Interestingly, the developed mesoscopic Monte Carlo (MC) method has the capacity to concurrently capture the elasticity and fluidity of fluid membranes well on large time and length scales, as well as to successfully reproduce fluctuating membrane morphology as observed in experiments. In this review, we focus on this mesoscopic MC method used to depict the thermodynamics of fluctuating fluid membranes and further explore how diverse biophysical factors drive large membrane curvature generation. We also discuss the current efforts of the roles of membrane morphology on the regulation of biological processes on the basis of this mesoscopic MC method, provide the insights into the known biomechanical mechanisms of effect of membrane shape on cellular functions, and point out the potential opportunities where this mesoscopic dynamic MC method can be modified to investigate more intricate biological processes, such as membrane fusion and adhesion.

Due to the superior physical properties and high-level alignment of the nanoscale building blocks, assembly of high-quality two-dimensional (2D) nanosheets into macroscopic engineering structure materials can achieve many unexpected performance. Natural mica nanosheets (MNSs) are abundant and with superlative properties, showing huge prospect for engineering structural materials. However, the difficulty of the mass production with large size and high aspect ratio are the current factors that limit this. Inspired by the well-known scotch-tape exfoliation, herein we develop a gummy-tape exfoliation (GTE) method by using liquid oligomers as mediums in ball-milling process to massively produce large-size and ultrathin MNSs. As a confirmation, the obtained MNSs show a record high aspect ratio of ≈1320 and a large actual yield of ∼ 80 %. A transparent biobased aromatic polyester nanocomposite film made of such MNSs and polyethylene furandicarboxylate (PEF) matrix possesses remarkably improved mechanical, barrier properties, and UV-shielding performances at an extremely low filler loading (≤0.5 vol%), making it a novel potential engineering material for packing fields in foods, drugs, and electronic products, etc.

Polylactic Acid (PLA) is a biodegradable polymer gaining popularity as a replacement for conventional plastics in different industrial sectors. However, PLA has inherent limitations and requires modifications to enhance its performance. This review article covers the different important aspects related to the PLA such as the synthesis route of PLA, biodegradation mechanism of PLA, properties of PLA, and applications of PLA in different sectors. The main focus of this review is to identify the different innovative copolymers, blends and composites of PLA for biomedical applications. Most important characteristics such as degradation behavior, biocompatibility and mechanical properties of these PLA-based biodegradable polymers were briefly discussed. This review indicates that the optimization of processing techniques and suitable selection of additives play an important role to achieve the desired properties of PLA. This review also discusses the issues associated to PLA-based materials for biomedical applications.