Insight into the Feasibility of Fatty Acyl Chlorides with 10-18 Carbons for the Ball-Milling Synthesis of Thermoplastic Cellulose Esters.

Fatty acid cellulose esters (FACE) are common cellulose-based thermoplastics, and their thermoplasticity is determined by both the contents and the lengths of the side chains. Herein, various FACE were synthesized by the ball-milling esterification of cellulose and fatty acyl chlorides containing 10-18 carbons, and their structures and thermoplasticity were thoroughly studied. The results showed that FACE with high degrees of substitution (DS) and low melting flow temperatures () were achieved as the chain lengths of the fatty acyl chlorides were reduced.

Polypyrrole@CNT@PU Conductive Sponge-Based Triboelectric Nanogenerators for Human Motion Monitoring and Self-Powered Ammonia Sensing.

Elastic sponges are ideal materials for triboelectric nanogenerators (TENGs) to harvest irregular and random mechanical energy from the environment. However, the conductive design of the elastic materials in TENGs often limits its applications. In this work, we have demonstrated that an elastic conductive sponge can be used as the triboelectric layer and electrode for TENGs.

Hierarchically Porous Implants Orchestrating a Physiological Viscoelastic and Piezoelectric Microenvironment for Bone Regeneration.

The extracellular matrix microenvironment of bone tissue comprises several physiological cues. Thus, artificial bone substitute materials with a single cue are insufficient to meet the demands for bone defect repair. Regeneration of critical-size bone defects remains challenging in orthopedic surgery.

Metal-Organic Framework Based Triboelectric Nanogenerator for a Self-Powered Methanol Sensor with High Sensitivity and Selectivity.

Triboelectric nanogenerators have shown great potential in the area of self-powered gas sensors in the past decade. In this paper, we developed a triboelectric nanogenerator (TENG) based on spiky structured ZIF-8@ZnO, which can harvest energy with high efficiency and act as a self-powered methanol sensor. The open-circuit voltage and short-circuit current generated by a ZIF-8@ZnO-based TENG is 58 V and 10 μA, achieving 2.

3- to 24-month Follow-up on COVID-19 with Pulmonary Tuberculosis Survivors after Discharge: Results from a Prospective, Multicenter Study.

Objective: Coronavirus disease 2019 (COVID-19) and tuberculosis (TB) are major public health and social issues worldwide. The long-term follow-up of COVID-19 with pulmonary TB (PTB) survivors after discharge is unclear. This study aimed to comprehensively describe clinical outcomes, including sequela and recurrence at 3, 12, and 24 months after discharge, among COVID-19 with PTB survivors.

A Wave-Driven Piezoelectrical Film for Interfacial Steam Generation: Beyond the Limitation of Hydrogel.

Solar interfacial vapor generation based on low evaporation energy requirements is an effective technology to speed up water purification under natural sunlight, offering great potential to alleviate the current global water crisis. The external electric field and hydrogel are two independent methods enabling low-energy water evaporation. However, the complicated external equipment for generating an electric field and the restricted activation area of hydrogels significantly limit their practical application in steam generation.

Janus and Heteromodulus Elastomeric Fiber Mats Feature Regulable Stress Redistribution for Boosted Strain Sensing Performance.

Wearable strain sensors have huge potential for applications in healthcare, human-machine interfacing, and augmented reality systems. However, the nonlinear response of the resistance signal to strain has caused considerable difficulty and complexity in data processing and signal transformation, thus impeding their practical applications severely. Herein, we propose a simple way to achieve linear and reproducible resistive signals responding to strain in a relatively wide strain range for flexible strain sensors, which is achieved via the fabrication of Janus and heteromodulus elastomeric fiber mats with micropatterns using microimprinting second processing technology.

Vitrimeric Polylactide by Two-step Alcoholysis and Transesterification during Reactive Processing for Enhanced Melt Strength.

Because of its rather low melt strength, polylactide (PLA) has yet to fulfill its promise as advanced biobased and biodegradable foams to replace fossil-based polymer foams. In this work, PLA vitrimers were prepared by two-step reactive processing from commercial PLA thermoplastics, glycerol, and diphenylmethane diisocyanate (MDI) using Zn(II)-catalyzed addition and transesterification chemistry. The transesterification reaction of PLA and glycerol occurs with zinc acetate as the catalyst, and chain scission will take place due to the alcoholysis of the PLA chains by the free hydroxyl groups from the glycerol.

A Case Series of Olfactory Dysfunction in Imported COVID-19 Patients: A 12-Month Follow-Up Study.

Objective: The scientific community knows little about the long-term influence of coronavirus disease 2019 (COVID-19) on olfactory dysfunction (OD). With the COVID-19 pandemic ongoing worldwide, the risk of imported cases remains high. In China, it is necessary to understand OD in imported cases.

Self-Sensing Actuators Based on a Stiffness Variable Reversible Shape Memory Polymer Enabled by a Phase Change Material.

Soft actuators with integrated mechanical and actuation properties and self-sensing ability are still a challenge. Herein, a stiffness variable polyolefin elastomer (POE) with a reversible shape memory effect is prepared by introducing a typical phase change material, i.e.

A hierarchically combined reduced graphene oxide/Nickel oxide hybrid supercapacitor device demonstrating compliable flexibility and high energy density.

This work demonstrates a hierarchical structure design with mixed holey graphene oxide (HGO) and Ni(OH) active material layer made by one-pot hydrothermal reaction clinging to Nickel foam as backbone and ice-template oriented graphene oxide (GO) aerogel as filling, aiming to create an asymmetric solid supercapacitor (ASC) device with compliable flexibility and high electrochemical performance. The effects of hydrothermal treatment and ice-template freezing parameters on electrochemical stability under repeated exterior deformation are discussed, the optimal parameters result in a high areal capacitance of 479.8 mF/cm in asymmetric supercapacitor device setup.

Macromolecule Relaxation Directed 3D Nanofiber Architecture in Stretchable Fibrous Mats for Wearable Multifunctional Sensors.

Elastomer fiber mat sensors, which are capable of perceiving mechanical stimuli, temperature, and vapor of chemicals, are highly desirable for designing wearable electronics and human-robot interfacing devices due to good wearability, skin affinity, and durability, and so on. However, it is still challenging to fabricate multiresponsive flexible wearable sensors with three-dimensional (3D) architecture using simple material and structure design. Herein, we report an all-in-one multiresponsive thermoplastic polyurethane (TPU) nanofiber mat sensors composed of crimped elastomer fibers with deposited platinum nanoparticles (PtNPs) on the fiber surface.

Interfacial Radiation-Absorbing Hydrogel Film for Efficient Thermal Utilization on Solar Evaporator Surfaces.

Solar water purification is a promising technology with a strong potential for producing fresh water without effluent discharge. For energy-intensive interfacial vapor generation, energy loss to air via heat radiation and convection occurs commonly but is normally ignored, which severely limits the energy efficiency. Therefore, it is necessary to precisely regulate the interfacial thermal energy for interfacial vapor generation.

Scalable Flexible Phase Change Materials with a Swollen Polymer Network Structure for Thermal Energy Storage.

3D porous structural materials are proved to be enticing candidates for the fabrication of high-performance organic phase change materials (PCMs), but the stringent fabrication process and poor processability greatly hampered their commercialization. Herein, flexible leakage-proof composite PCMs with pronounced comprehensive performance are fabricated by a scalable polymer swelling strategy without using any solvent, in which the paraffin wax (PW) segment is confined in a robust flexible 3D polymer network, giving rise to the composite PCMs with excellent form stability even at 160 °C, a high latent heat energy storage density of 133.6 J/g, and an outstanding thermal conductivity of up to ∼5.

Recent Advances in Multiresponsive Flexible Sensors towards E-skin: A Delicate Design for Versatile Sensing.

Multiresponsive flexile sensors with strain, temperature, humidity, and other sensing abilities serving as real electronic skin (e-skin) have manifested great application potential in flexible electronics, artificial intelligence (AI), and Internet of Things (IoT). Although numerous flexible sensors with sole sensing function have already been reported since the concept of e-skin, that mimics the sensing features of human skin, was proposed about a decade ago, the ones with more sensing capacities as new emergences are urgently demanded. However, highly integrated and highly sensitive flexible sensors with multiresponsive functions are becoming a big thrust for the detection of human body motions, physiological signals (e.

Phase change mediated mechanically transformative dynamic gel for intelligent control of versatile devices.

Traditional devices, including conventional rigid electronics and machines, as well as emerging wearable electronics and soft robotics, almost all have a single mechanical state for particular service purposes. Nonetheless, dynamic materials with interchangeable mechanical states, which enable more diverse and versatile applications, are urgently necessary for intelligent and adaptive application cases in the future electronic and robot fields. Here, we report a gel-like material composed of a crosslinking polymer network impregnated with a phase changing molten liquid, which undergoes an exceptional stiffness transition in response to a thermal stimulus.

Aligned wave-like elastomer fibers with robust conductive layers electroless deposition for stretchable electrode applications.

Flexible wearable electronics play an important role in the healthcare industry due to their unique skin affinity, portability and breathability. Despite great progress, it still remains a big challenge to facilely fabricate stretchable electrodes with low resistance, excellent stability and a wide tensile range. Here, we propose a handy and time-saving strategy for the fabrication of elastomeric films consisting of wave-like fibers with a robust conductive layer of silver nanoparticles (AgNPs) immobilized using polydopamine (PDA) and silicone rubber (SR).

Fabrication of a NiO@NF supported free-standing porous carbon supercapacitor electrode using temperature-controlled phase separation method.

To address the problem that capacitor electrode being low in capacitance and reliant on binder to retain shape, a binder-free, self-supporting supercapacitor electrode is made via pyrolysis of porous polyacrylonitrile (PAN) formed by phase separation, supported by hydrothermally treated nickel foam backbone. The role of hydrothermal reaction time and PAN solution concentration on electrochemical properties was thoroughly studied, and the results indicate a generally peaked capacitance at 4 h of hydrothermal reaction time, but after a certain threshold, a supposed micro-domain buffering mechanism would take over and enhance the pseudocapacitance from NiO to reach a specific capacitance as high as 152 F/g at a high active material mass load of 14.98 mg/cm, providing the area specific capacitance up to 1.

Biobinder Nanocoating for Upgrading the Assembling Structures of High-Capacity Composite Electrodes with a Robust Polymeric Artificial Solid Electrolyte Interphase.

The success of next-generation lithium-ion batteries (LIBs) fundamentally depends on the rational design of not only the microstructure of an individual component but the component assembling structures on the electrode level. However, building advanced assembling structures for especially high-capacity electrodes is an urgent but a challenging task due to the lacking of in-depth understanding and effective strategies. Here, we propose a functional nanocoating biobinder using the well-known poly(lactic acid) to address the above need.

Waterproof Phase Change Material with a Facilely Incorporated Cellulose Nanocrystal/Poly(-isopropylacrylamide) Network for All-Weather Outdoor Thermal Energy Storage.

The incorporation of porous supporting materials to prepare shape-stable phase change materials (PCMs) is of great interest in recent years. However, extensive reported composite PCMs are shape-stable in the air atmosphere but neglected in the water environment. To develop shape-stable and waterproof PCMs is important for their outdoor applications but challenging.

Smart TiCT MXene Fabric with Fast Humidity Response and Joule Heating for Healthcare and Medical Therapy Applications.

An increasing utilization of flexible healthcare electronics and biomedicine-related therapeutic materials urges the development of multifunctional wearable/flexible smart fabrics for personal therapy and health management. However, it is currently a challenge to fabricate multifunctional and on-body healthcare electronic devices with reliable mechanical flexibility, excellent breathability, and self-controllable joule heating effects. Here, we fabricate a multifunctional MXene-based smart fabric by depositing 2D TiCT nanosheets onto cellulose fiber nonwoven fabric special MXene-cellulose fiber interactions.

A facile strategy towards heterogeneous preparation of thermoplastic cellulose grafted polyurethane from amorphous regenerated cellulose paste.

Cellulose is an abundant feedstock with renewability and biodegradability. However, it is still challenging to manufacture natural cellulose products by environmentally friendly thermoplastic processing methods. Herein, we proposed a green approach for the heterogeneous preparation of thermoplastic cellulose grafted polyurethane (RCP-g-PU) from amorphous regenerated cellulose paste (RCP) via hydroxyl/isocyanate chemistry.

Nanofibrillar Poly(vinyl alcohol) Ionic Organohydrogels for Smart Contact Lens and Human-Interactive Sensing.

Hydrogel bioelectronics as one of the next-generation wearable and implantable electronics ensures excellent biocompatibility and softness to link the human body and electronics. However, volatile, opaque, and fragile features of hydrogels due to the sparse and microscale three-dimensional network seriously limit their practical applications. Here, we report a type of smart and robust nanofibrillar poly(vinyl alcohol) (PVA) organohydrogels fabricated via one-step physical cross-linking.

Photo-Driven Self-Healing of Arbitrary Nondestructive Damage in Polyethylene-Based Nanocomposites.

Polymer products with precise shape recovery behavior are highly desired for practical applications owing to excellent processability and mechanical properties compared with metallic or inorganic materials. Shape memory polymers (SMPs) provide a solution for this end, but the design and scalable fabrication of photothermal controllable SMPs with accurate, rapid, and repeatable recovery behaviors are still great challenges. In this work, polyurethane/sulfonated carbon nanotube (PU/S-CNT) composite particles are introduced into a cross-linked high-density polyethylene (HDPE) as a functional dispersed phase to realize photo-driven fast shape recovery in cheap polymer composite materials.