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1.
Polymers (Basel) ; 15(18)2023 Sep 07.
Artigo em Inglês | MEDLINE | ID: mdl-37765535

RESUMO

Thermoplastic poly(ether/ester) elastomer (TPEE) has great potential as a mattress material due to its high resilience, breathability, and light weight. This study aimed to evaluate the feasibility of TPEE-3D fibrous material (T3DF), a three-dimensional block material made of TPEE fibers randomly aligned and loop-connected, for mattress application. After testing the compression properties of T3DF, the effects of T3DF structural layers on mattress firmness were investigated. The results showed that T3DF had good energy absorption capacity, broad indentation hardness range (126.94-333.82 N), and high compression deflection coefficient (2.79-4.39). The thickness and density of T3DF were the main factors influencing mattress firmness, and the impact of thickness was more significant (p < 0.05). Owing to the hard and soft segments contained in TPEE, T3DF could be used for both the padding and core layers of the mattress. The hardness value and Dsurface of the mattress with a T3DF padding layer increased with T3DF density but decreased with T3DF thickness. Moreover, the hardness value and Dsurface of the mattress with a T3DF core layer increased with T3DF density, while with T3DF thickness, its Dsurface increased and Dbottom decreased. Therefore, the thick and low-density T3DF padding layer could improve the comfort of the mattress surface, a thin T3DF core layer could satisfy both the softer surface and the firmer bottom of the mattress.

2.
Chem Commun (Camb) ; 59(20): 2854-2868, 2023 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-36752217

RESUMO

Heterogeneous catalysis is an important class of reactions in industrial production, especially in green chemical synthesis, and environmental and organic catalysis. Single-atom catalysts (SACs) have emerged as promising candidates for heterogeneous catalysis, due to their outstanding catalytic activity, high selectivity, and maximum atomic utilization efficiency. The high specific surface energy of SACs, however, results in the migration and aggregation of isolated atoms under typical reaction conditions. The controllable preparation of highly efficient and stable SACs has been a serious challenge for applications. Herein, we summarize the recent progress in the precise synthesis of SACs and their different heterogeneous catalyses, especially involving the oxidation and reduction reactions of small organic molecules. At the end of this review, we also introduce the challenges confronted by single-atom materials in heterogeneous catalysis. This review aims to promote the generation of novel high-efficiency SACs by providing an in-depth and comprehensive understanding of the current development in this research field.

3.
Small ; 19(18): e2207467, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-36634976

RESUMO

Utilization of low-energy photons for efficient photocatalysis remains a challenging pursuit. Herein, a strategy is reported to boost the photocatalytic performance, by promoting low-energy photons dual harvest through bimodal surface plasmon resonance (SPR)-enhanced synergistically upconversion and pyroelectricity. It is achieved by introducing triplet-triplet annihilation upconversion (TTA-UC) materials and plasmonic material (Au nanorods, AuNRs) into composite fibers composed of pyroelectric substrate (poly(vinylidene fluoride)) and photocatalyst Cd0.5 Zn0.5 S. Interestingly, the dual combination of TTA-UC and AuNRs SPR in the presence of polyvinylidene fluoride substrate with pyroelectric property promotes the photocatalytic hydrogen evolution performance by 2.88 folds with the highest average apparent quantum yield of 7.0% under the low-energy light (λ > 475 nm), which far outweighs the role of separate application of TTA-UC (34%) and AuNRs SPR (76%). The presence of pyroelectricity plays an important role in the built-in electric field as well as the accordingly photogenerated carrier behavior in the composite photocatalytic materials, and the pyroelectricity can be affected by AuNRs with different morphologies, which is proved by the Kelvin probe force microscopy and photocurrent data. This work provides a new avenue for fully utilizing low-energy photons in the solar spectrum for improving photocatalytic performance.

4.
Ergonomics ; 66(10): 1477-1493, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-36437772

RESUMO

Knowledge of the parameters of the human spine is essential in designing ergonomic furniture. The purpose of this study was to evaluate spinal alignment in adolescents of various ages. The lengths, curvatures, and concave-convex spacings of the spine were investigated in 268 participants aged 9-18 years. Ten ages were classified, and the rate of increase of parameters was calculated for each age and age group. The results showed that spinal parameters, except for cervical lordosis, increased with age. Adolescents were classified as 9-10, 11-12, 13-15, and 16-18 years old. A rapid increment of lengths and concave-convex spacings occurred at ages 13-15, while that of curvatures occurred at ages 16-18. Spinal parameters differed significantly among the age groups (p < 0.05). Concave-convex spacings reflected differences in the spine more clearly than the other parameters. This study suggests the necessity of designing spine-related furniture based on spinal parameters, thus providing adaptive support for the adolescent spine, particularly the lumbar spine. Practitioner summary: This study examined spinal lengths, curvatures, and concave-convex spacings in adolescents aged 9-8 years and then divided them into four age groups. Concave-convex spacings effectively reflected spinal differences between age groups, particularly the lumbar spine. These results can inform the ergonomic design of spine-related furniture.HIGHLIGHTSSpinal parameters increased progressively between 9 and 18 years. Regression analysis showed good linear correlations between TK, LL, SK, TS, and LS with age.Age classification of adolescents was Group I (9-10 years), Group II (11-12 years), Group III (13-15 years), and Group IV (16-18 years). The rapid increment of lengths and concave-convex spacings were in Group III while that of curvatures were in Group IV.Concave-convex spacings were vital parameters to evaluate the global balance of the spine.The lumbar spine is an essential segment for characterizing spinal alignment.


Assuntos
Lordose , Escoliose , Adolescente , Humanos , Decoração de Interiores e Mobiliário , Coluna Vertebral , Vértebras Lombares
5.
Adv Mater ; 32(12): e1906361, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32048360

RESUMO

Infrared light, more than 50% of the solar light energy, is long-termly ignored in the photocatalysis field due to its low photon energy. Herein, infrared-light-responsive photoinduced carriers driver is first constructed taking advantage of pyroelectric effect for enhancing photocatalytic hydrogen evolution. In order to give full play to its role, the photocatalytic reaction is localized on the surface and interface of the composite based on a new semi-immersion type heat collected photocatalytic microfiber system. The system is consisted of distinctive pyroelectric substrate poly(vinylidene fluoride-co-hexafluropropylene (PVDF-HFP), typical photothermal material carbon nanotube (CNT), and representative photocatalyst CdS. The transient photocurrent, electrochemical impedance spectroscopy, time-resolved photoluminescence and pyroelectric potential characterizations indicate that the infrared-light-responsive carriers driver significantly promotes the photogenerated charge separation, accelerates carrier migration, and prolongs carrier lifetime. The photocatalytic hydrogen evolution efficiency is remarkably improved more than five times with the highest average apparent quantum yield of 16.9%. It may open up new horizons to photocatalytic technology for the more efficient use of infrared light.

6.
ACS Appl Mater Interfaces ; 12(1): 717-726, 2020 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-31813218

RESUMO

To avoid secondary environmental pollution caused by photocatalysts in their applications, our work offers a new strategy for fabricating photocatalytic films based on plasmon-enhanced triplet-triplet annihilation upconversion (TTA-UC). Polydimethylsiloxane (PDMS) films containing platinum (II)-octaethylporphyrin and 9,10-diphenylanthracene (PtDPAP), and gold nanoparticles (AuNPs) were prepared. While graphene (G) was used as an adhesive and conductive layer, CdS nanoparticles were deposited onto the films (AuNPs-PtDPAP/G/CdS) by plasma glow discharge pretreatment. The AuNPs-PtDPAP film had an enhancement in the green-to-blue upconversion compared with the pristine PtDPAP film. CdS can utilize the AuNPs plasmon-enhanced TTA-UC photons to realize efficient photocatalytic reactions. The pseudo-first-order rate constant (kpfo) of the optimized active and stable photocatalytic film, 0.3 AuNPs-PtDPAP/G/CdS, reached 0.294 h-1 for tetracycline degradation under green light irradiation. Its kpfo in decomposing tetracycline under visible light is 2.62 times higher than that of the PtDPAP/G/CdS. The reported composite films provide a strategy to improve the photocatalytic activity and promote the practical applications of nanosize photocatalysts.

7.
Nanotechnology ; 29(4): 045601, 2018 Jan 26.
Artigo em Inglês | MEDLINE | ID: mdl-29199974

RESUMO

Fluorescent photonic crystal films composed of monodisperse NaYF4:15Yb,0.5Tm@SiO2 (where 15 and 0.5 represent the mole percentage of reactants) core-shell spheres were successfully fabricated and applied in photocatalysis. The core-shell spheres were prepared using a modified Stober method, and fluorescent photonic crystal films were fabricated via a simple self-assembly method. The morphologies, structures and upconversion fluorescent properties of the fluorescent photonic crystal films with different photonic band gaps were characterized. Moreover, their photocatalytic capability in decomposing rhodamine B using near-infrared light was studied. Results indicate that the band edge effect plays a critical role in the enhancement of short wave emission intensity of fluorescent photonic crystal films. Specifically, in comparison to the reference sample without a band edge effect, the 363 nm emission intensity was enhanced by 5.97 times, while the percentage of UV upconversion emission was improved by 6.23%. In addition, the 451 nm emission intensity was enhanced by 5.81 times, and the percentage of visible upconversion emission was improved by 8.88%. Furthermore, fluorescent photonic crystal films with enhanced short wave emission exhibited great photocatalytic performance in the degradation of rhodamine B aqueous solutions under near-infrared light.

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