Ultraflexible Sensor Development via 4D Printing: Enhanced Sensitivity to Strain, Temperature, and Magnetic Fields.

This paper addresses the trade-off between sensitivity and sensing range in strain sensors, while introducing additional functionalities through an innovative 4D printing approach. The resulting ultraflexible sensor integrates carbon nanotubes/liquid metal hybrids and iron powders within an Ecoflex matrix. The optimization of this composition enables the creation of an uncured resin ideal for Direct Ink Writing (DIW) and a cured sensor with exceptional electromechanical, thermal, and magnetic performance.

Nanoconfinement-Enhanced Fire Safety and Mechanical Properties of Polylactic Acid with Nanocerium Metal-Organic Frameworks.

Ce-based metal-organic frameworks (Ce-MOFs) were successfully synthesized by coordinating binary acid and amino structures with cerium oxides. The quantum dot scale endows Ce-MOFs with enhanced modifiability. Additionally, the phosphorus-rich biomass phytic acid, with its numerous hydroxyl groups, strengthens the H-bond network within the system.

3D Printed Conformal Strain and Humidity Sensors for Human Motion Prediction and Health Monitoring via Machine Learning.

Wearable sensors have garnered considerable attention due to their flexibility and lightweight characteristics in the realm of healthcare applications. However, developing robust wearable sensors with facile fabrication and good conformity remains a challenge. In this study, a conductive graphene nanoplate-carbon nanotube (GC) ink is synthesized for multi jet fusion (MJF) printing.

4D Printing of Reprogrammable Liquid Crystal Elastomers with Synergistic Photochromism and Photoactuation.

4D printing of liquid crystal elastomers (LCEs) via direct ink writing has opened up great opportunities to create stimuli-responsive actuations for applications such as soft robotics. However, most 4D-printed LCEs are limited to thermal actuation and fixed shape morphing, posing a challenge for achieving multiple programmable functionalities and reprogrammability. Here, a 4D-printable photochromic titanium-based nanocrystal (TiNC)/LCE composite ink is developed, which enables the reprogrammable photochromism and photoactuation of a single 4D-printed architecture.

Spectroscopic Identification of Active Sites of Oxygen-Doped Carbon for Selective Oxygen Reduction to Hydrogen Peroxide.

The electrochemical synthesis of hydrogen peroxide (H O ) via a two-electron (2 e ) oxygen reduction reaction (ORR) process provides a promising alternative to replace the energy-intensive anthraquinone process. Herein, we develop a facile template-protected strategy to synthesize a highly active quinone-rich porous carbon catalyst for H O electrochemical production. The optimized PCC material exhibits remarkable activity and selectivity, of which the onset potential reaches 0.

Surface Modification of Hetero-phase Nanoparticles for Low-Cost Solution-Processable High-k Dielectric Polymer Nanocomposites.

The surface modification of nanoparticles (NPs) is crucial for fabricating polymer nanocomposites (NCs) with high dielectric permittivity. Here, we systematically studied the effect of surface functionalization of TiO and BaTiO NPs to enhance the dielectric permittivity of polyvinylidene fluoride (PVDF) NCs by 23 and 74%, respectively, measured at a frequency of 1 kHz. To further increase the dielectric permittivity of PVDF/NPs-based NCs, we developed a new hetero-phase filler-based approach that is cost-effective and easy to implement.

Hindered phenolic antioxidant passivation of black phosphorus affords air stability and free radical quenching.

As an antioxidant, hindered phenol scavenges free radicals. Due to the oxidative degradation of black phosphorus (BP) in the presence of water and oxygen, free radical quenching of hindered phenol antioxidants can solve this issue and improve the environmental stability and flame retardant efficiency of BP. Herein, hydroxyl-modified BP (BP-OH) with active groups on the surface was obtained by hydroxylation, and then the hindered phenol antioxidant was grafted onto the surface of BP-OH through an isophorone diisocyanate bridging covalent reaction to obtain hindered phenol-modified BP (BP-HPL).

Hierarchical Structure: An effective Strategy to Enhance the Mechanical Performance and Fire Safety of Unsaturated Polyester Resin.

It is still a big challenge to prepare polymer/layered double hydroxide (LDH) composites with high performance, due to the strong agglomeration tendency of LDHs in the polymeric matrix. In this study, to avoid the agglomerated situation, the orientated LDH nanosheets were vertically grown on a ramie fabric surface, which was then embedded in unsaturated polyester resin (UPR) through the combination method of hand lay-up and vacuum bag. Due to the increased contact area and the restricted interfacial slip in the in-plane direction, the hierarchically LDH-functionalized ramie fabrics (denoted as Textile@LDH) significantly enhanced the mechanical performance of UPR composites.

BiSe decorated recyclable liquid-exfoliated MoS nanosheets: Towards suppress smoke emission and improve mechanical properties of epoxy resin.

Bimetallic compounds have been proved superior suppression effect on smoke emission during combustion of polymers. In this work, MoS/BiSe (MB) hybrids were prepared by a facile wet chemical method and showed superior performance on smoke suppression of EP matrix during combustion. N-vinyl pyrrolidone (NVP) was employed to exfoliate molybdenum disulfide (MoS) nanosheets in a recyclable method, which showed high efficiency and was recyclable.

Construction of Hierarchical Natural Fabric Surface Structure Based on Two-Dimensional Boron Nitride Nanosheets and Its Application for Preparing Biobased Toughened Unsaturated Polyester Resin Composites.

It has been a big challenge to prepare the unsaturated polyester resin (UPR) composites with good fire safety, interfacial quality, and impact strength in an environmentally friendly way. In this study, to improve interfacial performance of fabric-reinforced UPR composites, nontoxic two-dimensional hexagonal boron nitride (h-BN) nanosheets were assembled on the surface of ramie fabrics, where sodium alginate acts as a green dispersant to disperse h-BN sheets during the process. Then, the biobased phosphorus-containing toughening agent (PCTA) was synthesized to simultaneously improve the impact strength and fire safety of the composite.

Rapid Synthesis of Oxygen-Rich Covalent CN (CNO) Nanosheets by Sacrifice of HKUST-1: Advanced Metal-Free Nanofillers for Polymers.

A covalent oxygen-rich CN (CNO) network derived from metal-organic framework (HKUST-1) was innovatively synthesized by a rapid and green microwave irradiation method. This method can produce CNO multilayers efficiently, which paves a way for practical application of the nanosheets. Structural characterization and synthesis processes of CNO nanosheets were investigated to further understand the key role of HKUST-1.

Construction of Bimetallic ZIF-Derived Co-Ni LDHs on the Surfaces of GO or CNTs with a Recyclable Method: Toward Reduced Toxicity of Gaseous Thermal Decomposition Products of Unsaturated Polyester Resin.

This work proposed an idea of recycling in preparing Co-Ni layered double hydroxide (LDH)-derived flame retardants. A novel and feasible method was developed to synthesize CO-Ni LDH-decorated graphene oxide (GO) and carbon nanotubes (CNTs), by sacrificing bimetal zeolitic imidazolate frameworks (ZIFs). Organic ligands that departed from ZIFs were recyclable and can be reused to synthesize ZIFs.

DOPO-Modified Two-Dimensional Co-Based Metal-Organic Framework: Preparation and Application for Enhancing Fire Safety of Poly(lactic acid).

Co-based metal-organic framework (Co-MOF) nanosheets were successfully synthesized by the organic ligands with Schiff base structure. The laminated structure gives Co-MOF nanosheets a great advantage in the application in the flame retardant field. Meanwhile, -C═N- from Schiff base potentially provides active sites for further modification.

Construction of flame retardant coating on polyamide 6.6 via UV grafting of phosphorylated chitosan and sol-gel process of organo-silane.

Phosphorylated chitosan (PCS) was synthesized and grafted onto the surface of polyamide 6.6 (PA 6.6) fabrics via UV-induced grafting polymerization in order to improve the flame retardant properties.

Effect of cuprous oxide with different sizes on thermal and combustion behaviors of unsaturated polyester resin.

Cuprous oxide (CuO) as an effective catalyst has been applied to enhance the fire safety of unsaturated polyester resin (UPR), but the particle size influence on combustion behaviors has not been previously reported. Herein, the UPR/CuO composites (metal oxide particles with average particle-size of 10, 100, and 200nm) were successfully synthesized by thermosetting process. The effects of CuO with different sizes on thermostability and combustion behaviors of UPR were characterized by TGA, MCC, TG-IR, FTIR, and SSTF.