Generally, self-healing
research based on commercial rubber is
of great significance in sustainable development by extending the
lifetime of materials. However, it is still a great challenge so far
to prepare recyclable rubber that combine excellent self-healing properties
with good mechanical strength and is also recyclable. Herein, we report
the use of epoxidized natural rubber (ENR), a reactive polymer presenting
dual functional groups (unsaturated double bonds and epoxy sites)
available for cross-linking, to prepare a dual cross-linked self-healing
ENR based on dynamic disulfide metathesis and thermoreversible hydrogen
bonding. Specifically, different structures of aromatic disulfide
compounds are introduced into the same system to promote the disulfide
metathesis and thus improving the self-healing efficiency of the material.
As a result, the dual cross-linked ENR shows high mechanical strength
(9.3 ± 0.3 MPa), high self-healing efficiency (up to 98%), and
ideal recyclability. In addition, cyclic fatigue tensile test shows
that the self-healing properties of the present material are not affected
by the damage forms, whether it is complete fracture or cyclic fatigue
damage. These outcomes are expected to promote the development of
self-healing technology in the sustainable application of cross-linked
rubber materials.
A psychophysical experiment has been carried out to investigate the impact of dynamic lighting parameters on atmosphere perception. The experiment was conducted in a purpose-built LED lighting lab, where the lighting could be spatially and dynamically changed and colorimetric specifications controlled. The aim of this study was to investigate the impacts of speed, saturation and brightness of dynamic lighting on the perceived atmosphere, preference and suitability for certain spaces. Twenty native Chinese observers participated in the experiment, each assessing the environment under dynamic lighting conditions using 21 atmosphere terms. The results show significant gender differences on some scales such as safe, spatial, chilly, formal, preference and office-like. Factor analysis showed that the 21 scales can be grouped into three categories: tenseness, coziness and liveliness, and that a living room-like atmosphere evaluation is consistent with coziness. Dynamic lighting does have a significant influence on atmosphere perception. A more saturated LED light would lead to less tense, more cosy, more safe and more lively atmosphere perceptions. By increasing the speed, a more tense and less cosy atmosphere can be generated. Medium speed offers the most lively and preferred atmosphere. Brighter lighting will generate a less tense environment. More saturated colour and a slower speed will produce a more living room-like environment, but it seems that such dynamic lighting is not suitable for an office-like environment.
Nitrate, a widespread contaminant in natural water, is a threat to ecological safety and human health. Although direct nitrate removal by electrochemical methods is efficient, the development of low-cost electrocatalysts with high reactivity remains challenging. Herein, bifunctional single-atom catalysts (SACs) were prepared with Cu or Fe active centers on an N-doped or S, N–codoped carbon basal plane for N2 or NH4+ production. The maximum nitrate removal capacity was 7,822 mg N ⋅ g−1 Fe, which was the highest among previous studies. A high ammonia Faradic efficiency (78.4%) was achieved at a low potential (−0.57 versus reversible hydrogen electrode), and the nitrogen selectivity was 100% on S-modified Fe SACs. Theoretical and experimental investigations of the S-doping charge-transfer effect revealed that strong metal–support interactions were beneficial for anchoring single atoms and enhancing cyclability. S-doping altered the coordination environment of single-atom centers and created numerous defects with higher conductivity, which played a key role in improving the catalyst activity. Moreover, interactions between defects and single-atom sites improved the catalytic performance. Thus, these findings offer an avenue for high active SAC design.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.