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1.
Article de Anglais | MEDLINE | ID: mdl-39356972

RÉSUMÉ

Electrocatalytic CO2 reduction reaction (CO2RR) emerges as a promising avenue to mitigate carbon emissions, enabling the capture and conversion of CO2 into high-value products such as syngas with CO/H2. One of the crucial aspects lies in the tailored development of durable and efficient electrocatalysts for the CO2RR. Covalent organic frameworks (COFs) possess unique characteristics that render them attractive candidates for catalytic applications. However, the relationship between structure and performance still requires further exploration; especially, most COFs with such properties are limited to COFs containing specific groups such as phthalocyanine or porphyrin groups. Here, we custom-synthesize two azine-linked nitrogen-rich COFs constructed from triazine building blocks, which are doped with ultrafine and highly dispersed Ag nanoparticles (Ag@TFPT-HZ and Ag@TPT-HZ). Thus-obtained COFs can serve as electrocatalysts for the CO2RR, and a comprehensive investigation has been conducted to uncover the intricate structure-performance relationship within these materials. Notably, Ag@TFPT-HZ exhibits superior CO selectivity in the electrocatalytic CO2RR, achieving a FECO of 81% and a partial current density of 7.65 mA·cm-2 at the potential of -1.0 V (vs reversible hydrogen electrode (RHE)). In addition, Ag@TPT-HZ as an electrocatalyst can continuously produce syngas with a CO/H2 molar ratio of 1:1, an ideal condition for methanol synthesis. The observed distinct performance between these two COFs is attributed to the presence of O atoms in TFPT-HZ. These O atoms facilitate a higher loading capacity of Ag nanoparticles (11 wt %) and generate a greater number of active sites, thereby enhancing electrochemical activity and promoting faster reaction kinetics. Therefore, two tailor-made two-dimensional (2D) nitrogen-rich COFs with various active sites as electrocatalysts can exhibit different outstanding electrocatalytic performances for CO2RR and possess high cycling stability (>50 h). This work offers valuable insights into the design and synthesis of electrocatalysts, particularly in elucidating the intricate relationship between their structure and performance.

2.
ACS Nano ; 2024 Sep 11.
Article de Anglais | MEDLINE | ID: mdl-39259947

RÉSUMÉ

Sensorineural hearing loss (SNHL) represents a significant clinical challenge, predominantly attributed to oxidative stress-related mechanisms. In this work, we report an innovative antioxidant strategy for mitigating SNHL, utilizing synthetically engineered allomelanin nanoparticles (AMNPs). Empirical evidence elucidates AMNPs' profound capability in free radical neutralization, substantiated by a significant decrement in reactive oxygen species (ROS) levels within HEI-OC1 auditory cells exposure to cisplatin or hydrogen peroxide (H2O2). Comparative analyses reveal that AMNPs afford protection against cisplatin-induced and noise-induced auditory impairments, mirroring the effect of dexamethasone (DEX), a standard pharmacological treatment for acute SNHL. AMNPs exhibit notable cytoprotective properties for auditory hair cells (HCs), effectively preventing ototoxicity from cisplatin or H2O2 exposure, as confirmed by both in vitro assays and cultured organ of Corti studies. Further in vivo research corroborates AMNPs' ability to reverse auditory brainstem response (ABR) threshold shifts resulting from acoustic injury, concurrently reducing HCs loss, ribbon synapse depletion, and spiral ganglion neuron degeneration. The therapeutic benefits of AMNPs are attributed to mitigating oxidative stress and inflammation within the cochlea, with transcriptome analysis indicating downregulated gene expression related to these processes post-AMNPs treatment. The pronounced antioxidative and anti-inflammatory effects of AMNPs position them as a promising alternative to DEX for SNHL treatment.

3.
Hear Res ; 450: 109048, 2024 09 01.
Article de Anglais | MEDLINE | ID: mdl-38852535

RÉSUMÉ

The Blood-Labyrinth Barrier (BLB) is pivotal for the maintenance of lymphatic homeostasis within the inner ear, yet the intricacies of its development and function are inadequately understood. The present investigation delves into the contribution of the Mfsd2a molecule, integral to the structural and functional integrity of the Blood-Brain Barrier (BBB), to the ontogeny and sustenance of the BLB. Our empirical findings delineate that the maturation of the BLB in murine models is not realized until approximately two weeks post-birth, with preceding stages characterized by notable permeability. Transcriptomic analysis elucidates a marked augmentation in Mfsd2a expression within the lateral wall of the cochlea in specimens exhibiting an intact BLB. Moreover, both in vitro and in vivo assays substantiate that a diminution in Mfsd2a expression detrimentally impacts BLB permeability and structural integrity, principally via the attenuation of tight junction protein expression and the enhancement of endothelial cell transcytosis. These insights underscore the indispensable role of Mfsd2a in ensuring BLB integrity and propose it as a viable target for therapeutic interventions aimed at the amelioration of hearing loss.


Sujet(s)
Barrière hémato-encéphalique , Oreille interne , Symporteurs , Jonctions serrées , Transcytose , Animaux , Jonctions serrées/métabolisme , Barrière hémato-encéphalique/métabolisme , Oreille interne/métabolisme , Symporteurs/métabolisme , Symporteurs/génétique , Cellules endothéliales/métabolisme , Cellules endothéliales/anatomopathologie , Cochlée/métabolisme , Souris de lignée C57BL , Perméabilité capillaire , Protéine-2 à domaine MARVEL/métabolisme , Protéine-2 à domaine MARVEL/génétique , Souris knockout , Protéines de la jonction serrée/métabolisme , Protéines de la jonction serrée/génétique , Régulation de l'expression des gènes au cours du développement , Souris , Perméabilité
4.
Angew Chem Int Ed Engl ; 63(24): e202404505, 2024 Jun 10.
Article de Anglais | MEDLINE | ID: mdl-38598471

RÉSUMÉ

Ammonia borane (AB) with 19.6 wt % H2 content is widely considered a safe and efficient medium for H2 storage and release. Co-based nanocatalysts present strong contenders for replacing precious metal-based catalysts in AB hydrolysis due to their high activity and cost-effectiveness. However, precisely adjusting the active centers and surface properties of Co-based nanomaterials to enhance their activity, as well as suppressing the migration and loss of metal atoms to improve their stability, presents many challenges. In this study, mesoporous-silica-confined bimetallic Co-Cu nanoparticles embedded in nitrogen-doped carbon (CoxCu1-x@NC@mSiO2) were synthesized using a facile mSiO2-confined thermal pyrolysis strategy. The obtained product, an optimized Co0.8Cu0.2@NC@mSiO2 catalyst, exhibits enhanced performance with a turnover frequency of 240.9 molH2 ⋅ molmetal ⋅ min-1 for AB hydrolysis at 298 K, surpassing most noble-metal-free catalysts. Moreover, Co0.8Cu0.2@NC@mSiO2 demonstrates magnetic recyclability and extraordinary stability, with a negligible decline of only 0.8 % over 30 cycles of use. This enhanced performance was attributed to the synergistic effect between Co and Cu, as well as silica confinement. This work proposes a promising method for constructing noble-metal-free catalysts for AB hydrolysis.

5.
Angew Chem Int Ed Engl ; 62(40): e202305371, 2023 Oct 02.
Article de Anglais | MEDLINE | ID: mdl-37291046

RÉSUMÉ

Ammonia borane (AB) is a promising material for chemical H2 storage owing to its high H2 density (up to 19.6 wt %). However, the development of an efficient catalyst for driving H2 evolution through AB hydrolysis remains challenging. Therefore, a visible-light-driven strategy for generating H2 through AB hydrolysis was implemented in this study using Ni-Pt nanoparticles supported on phosphorus-doped TiO2 (Ni-Pt/P-TiO2 ) as photocatalysts. Through surface engineering, P-TiO2 was prepared by phytic-acid-assisted phosphorization and then employed as an ideal support for immobilizing Ni-Pt nanoparticles via a facile co-reduction strategy. Under visible-light irradiation at 283 K, Ni40 Pt60 /P-TiO2 exhibited improved recyclability and a high turnover frequency of 967.8 mol H 2 ${{_{{\rm H}{_{2}}}}}$ molPt -1 min-1 . Characterization experiments and density functional theory calculations indicated that the enhanced performance of Ni40 Pt60 /P-TiO2 originated from a combination of the Ni-Pt alloying effect, the Mott-Schottky junction at the metal-semiconductor interface, and strong metal-support interactions. These findings not only underscore the benefits of utilizing multipronged effects to construct highly active AB-hydrolyzing catalysts, but also pave a path toward designing high-performance catalysts by surface engineering to modulate the electronic metal-support interactions for other visible-light-induced reactions.

6.
Chem Soc Rev ; 52(12): 3991-4005, 2023 Jun 19.
Article de Anglais | MEDLINE | ID: mdl-37278085

RÉSUMÉ

Surface barriers to mass transfer in various nanoporous materials have been increasingly identified. These past few years especially, a significant impact on catalysis and separations has come to light. Broadly speaking, there are two types of barriers: internal barriers, which affect intraparticle diffusion, and external barriers, which determine the uptake and release rates of molecules into and out of the material. Here, we review the literature on surface barriers to mass transfer in nanoporous materials and describe how the existence and influence of surface barriers has been characterized, aided by molecular simulations and experimental measurements. As this is a complex, evolving research topic, without consensus from the scientific community at the time of writing, we present various current viewpoints, not always in agreement, on the origin, nature, and function of such barriers in catalysis and separation. We also emphasize the need for considering all the elementary steps of the mass transfer process in optimally designing new nanoporous and hierarchically structured adsorbents and catalysts.

7.
Langmuir ; 38(38): 11621-11630, 2022 Sep 27.
Article de Anglais | MEDLINE | ID: mdl-36107634

RÉSUMÉ

Clathrate hydrate growth, deposition, and plug formation during oil and gas transportation causes blockage of pipelines. An effective strategy to solve this problem is to mitigate the hydrate formation and reduce its adhesion on pipe walls through a coating process. However, durability failure, corrosion, inability to self-heal, high cost, and strong hydrate adhesion remain unsolved issues. To address these challenges, in this work, we present an in situ self-replenishing nonfluorinated durable hydrate-phobic coating of candle soot particles. The candle soot coating reduces hydrate adhesion by promoting a thick barrier film of hydrocarbons between the hydrate and the soot coated substrate. The hydrocarbons permeating the soot coating display a high contact angle for water and inhibit the formation of water bridges between the hydrate and soot coated substrate. The spherical cyclopentane hydrate slides off easily on the candle soot coating inside the cyclopentane environment. The hydrate former, cyclopentane-water emulsion, and THF-water mixture have high contact angles as well as low hydrate adhesion on soot coating simultaneously. In addition, the coating is flow-induced long-term slippery, durable, low cost, anticorrosion, self-cleaning, and suitable for practical applications.

8.
Ann Transl Med ; 10(2): 40, 2022 Jan.
Article de Anglais | MEDLINE | ID: mdl-35282134

RÉSUMÉ

Background: N6-methyladenosine (m6A) is the most frequent internal methylation of eukaryotic RNA (ribonucleic acid) transcripts and plays an important function in RNA processing. The current research aimed to investigate the role of m6A-STIM2 axis in cholangiocarcinoma (CCA) progression. Methods: The expression of STIM2 (Stromal Interaction Molecule 2) in CCA was measured using quantitative polymerase chain reaction (PCR) and immunohistochemistry (IHC). STIM2 was examined in vivo for its effects on the malignant phenotypes of CCA cells. The m6A modification of STIM2 was assessed through MeRIP (methylated RNA Immunoprecipitation)-PCR. Results: Based on the GEPIA (Gene Expression Profiling Interactive Analysis) 2 database findings, a low STIM2 mRNA (messenger RNA) level was related to a poor prognosis in individuals with CCA. Quantitative PCR and IHC assays indicated decreased protein satin in CCA tissues and were associated with extrahepatic metastasis. Vianude mice tail vein injection model indicated that increased STIM2 levels suppressed CCA cell metastasis in vivo, while KRT8 (keratin 8) was detected as the direct downstream target of STIM2-mediated CCA cell metastasis in vivo. Meanwhile, based on SRAMP database and MeRIP assays indicated that m6A alteration resulted in abnormal STIM2 expression in CCA via METTL14 and YTHDC2. Conclusions: Our findings revealed the epi-transcriptomic dysregulation in CCA and metastasis by proposing a complicated STIM2-KRT8 regulatory paradigm based on m6A alteration.

9.
Front Cell Dev Biol ; 9: 744838, 2021.
Article de Anglais | MEDLINE | ID: mdl-34621753

RÉSUMÉ

Optic atrophy1 (OPA1) is crucial for inner mitochondrial membrane (IMM) fusion and essential for maintaining crista structure and mitochondrial morphology. Optic atrophy and hearing impairment are the most prevalent clinical features associated with mutations in the OPA1 gene, but the function of OPA1 in hearing is still unknown. In this study, we examined the ability of Opa1 to protect against cisplatin-induced cochlear cell death in vitro and in vivo. Our results revealed that knockdown of Opa1 affects mitochondrial function in HEI-OC1 and Neuro 2a cells, as evidenced by an elevated reactive oxygen species (ROS) level and reduced mitochondrial membrane potential. The dysfunctional mitochondria release cytochrome c, which triggers apoptosis. Opa1 expression was found to be significantly reduced after cell exposed to cisplatin in HEI-OC1 and Neuro 2a cells. Loss of Opa1 aggravated the apoptosis and mitochondrial dysfunction induced by cisplatin treatment, whereas overexpression of Opa1 alleviated cisplatin-induced cochlear cell death in vitro and in explant. Our results demonstrate that overexpression of Opa1 prevented cisplatin-induced ototoxicity, suggesting that Opa1 may play a vital role in ototoxicity and/or mitochondria-associated cochlear damage.

10.
Langmuir ; 36(37): 10960-10969, 2020 09 22.
Article de Anglais | MEDLINE | ID: mdl-32864968

RÉSUMÉ

Polluted water is a worldwide problem; therefore, effective separation of oil/water and removal of dyes, organic micropollutants, and heavy metals in wastewater are the need of the hour. Herein, hydrophilic ß-cyclodextrin-grafted carboxymethyl cellulose, biodegradable polyvinyl alcohol, and chitosan were used as main raw materials to construct a multifunctional aerogel framework by simple sol-gel and directional freeze-drying methods. Featuring intrinsic superamphiphilic wettability in air, robust superoleophobic wettability underwater, and excellent shape-recovery characteristics, the biomass-derived aerogel presents durable oil/water separation even after 10 cycles. The aerogels possess prominent adsorption capacity for methyl blue, 1-naphthylamine, and Cu2+, which was as high as 121.55 mg/g, 33.96 mg/g, and 122.6 mg/g, respectively. In addition, various pollutant mixtures could be effectively adsorbed by the aerogel at the same time with the adsorption capacity of 121.75 mg/g for methyl blue, 0.97 mg/g for bisphenol A, and 20.11 mg/g for Cu2+.

11.
RSC Adv ; 10(33): 19157-19168, 2020 May 20.
Article de Anglais | MEDLINE | ID: mdl-35515474

RÉSUMÉ

Creating a robust omniphobic surface that repels various liquids would have broad technological implications for areas ranging from biomedical devices and fuel transport to architecture. The present omniphobic surfaces still have the problems of complex fabrication methods, high cost, and being environmentally harmful. To address these challenges, here we report a novel process to design a non-fluorinated, long-term slippery omniphobic surface of candle soot nanoparticles with a silicone binder that cures at room temperature. The porosity, nanoscale roughness, strong affinity of the substrate with the silicone lubricant, and retention of lubricant after curing of the binder play an important role in its stability and low ice adhesion strength at sub-zero temperature. The developed surface exhibits damage resistant slippery properties, repellency to several liquids with different surface tensions including blood, delay in freezing point along with ultra-low ice adhesion strength (2 kPa) and maintains it even below 7 kPa under harsh environmental conditions; 90 frosting/defrosting cycles at -90 °C; 2 months under an ice layer; 2 months at 60 °C; 9 days flow in acidic/basic water and exposure to super-cold water. In addition, this novel technique is cheap, easy to fabricate, environmentally benign and suitable for large-scale applications.

12.
ACS Appl Mater Interfaces ; 11(50): 46800-46807, 2019 Dec 18.
Article de Anglais | MEDLINE | ID: mdl-31738044

RÉSUMÉ

In next generation lithium-ion batteries (LIBs), silicon is a promising electrode material due to its surprisingly high specific capacity, but it suffers from serious volume changes during the lithiation/delithiation process which gradually lead to the destruction of the electrode structure. A novel fluorinated copolymer with three different polar groups was synthesized to overcome this problem: carboxylic acid, amide, and fluorinated groups on a single polymer backbone. Moreover, a dual cross-linked network binder was prepared by thermal polymerization of the fluorinated copolymer and sodium alginate. Unlike the common chemical cross-linked network with a gradual and nonreversible fracturing, the dual cross-linked network which combines chemical and physical cross-linking could effectively hold the silicon particles during the volume change process. As a result, excellent electrochemical performance (1557 mAh g-1 at a 4 A g-1 current density after 200 cycles) was achieved with this novel reversible cross-linked binder. Further research studies with regard to the influences of fluorine and acrylamide content were conducted to systematically evaluate the designed binder. Moreover, with the help of new binder, the silicon/graphite and silicon oxide/graphite electrode exhibit superb cycle performance with capacity fade rate of 0.1% and 0.025% per cycle over 200 and 700 cycles, respectively. This novel and unsophisticated design gives a result for fabrication of high-performance Si based electrodes and advancement of the realization of practical application.

13.
ACS Appl Mater Interfaces ; 11(34): 31532-31542, 2019 Aug 28.
Article de Anglais | MEDLINE | ID: mdl-31368296

RÉSUMÉ

Ice formation and accretion affect residential and commercial activities. Icephobic coatings decrease the ice adhesion strength (τice) to less than 100 kPa. However, rare icephobic coatings remove the ice under the action of gravity or natural winds. The icephobicity of such coatings depends on materials with low interfacial toughness. We develop durable candle soot icephobic coating with RTV-1 as a low-modulus binding material. Heterogeneous nucleation on 20-40 nm candle soot particles and their fracture mechanism are discussed. The developed coating always shows durable Cassie-Baxter superhydrophobic state with low ice adhesion (18 kPa) and maintains the τice value of about 25 kPa after severe mechanical abrasion, 30 liquid nitrogen/water cycles, 100 frosting/defrosting cycles, 100 icing/deicing cycles, acid/base exposure, under UV light, and exposure to natural freezing rain in Hangzhou. In addition, the proposed technique is time-efficient, inexpensive, and suitable for large-scale applications.

14.
Biopreserv Biobank ; 17(5): 425-432, 2019 Oct.
Article de Anglais | MEDLINE | ID: mdl-31025876

RÉSUMÉ

Background: High-throughput transcript sequencing plays an important role in the study of hepatocellular carcinoma (HCC) occurrence and development. High-quality biospecimens, especially high-quality RNA, are the most basic prerequisites for obtaining good transcript sequencing data. Our purpose was to explore the treatment conditions of in vitro ischemic tissue samples that can be used to obtain high-integrity RNA before freezing the samples in liquid nitrogen. Materials and Methods: Postoperative tumor tissues (T) and adjacent normal tissues (AN) from 50 HCC patients were randomly selected from May 5, 2017, to June 15, 2017. Postoperative tissue specimens from each HCC patient were stratified by tissue type (T or AN), ischemia time (minutes), and ischemia temperature (°C) into 16 groups: T-4°C-15 minutes, T-4°C-30 minutes, T-4°C-60 minutes, T-4°C-120 minutes, T-24°C-15 minutes, T-24°C-30 minutes, T-24°C-60 minutes, T-24°C-120 minutes, AN-4°C-15 minutes, AN-4°C-30 minutes, AN-4°C-60 minutes, AN-4°C-120 minutes, AN-24°C-15 minutes, AN-24°C-30 minutes, AN-24°C-60 minutes, and AN-24°C-120 minutes. RNA integrity was detected by RNA integrity number (RIN) and 1% agarose gel electrophoresis. Results: At an ischemia temperature of 4°C and ischemia time of >30 minutes, the RIN of T began to decrease. RIN also gradually decreased in T at an ischemia temperature of 4°C and in both T and AN at an ischemia temperature of 24°C for ischemia times 15, 30, 60, and 120 minutes. For an ischemia time ≤15 minutes and ischemia temperature 4°C or 24°C, the RINs of T and AN were significantly different. Furthermore, at ischemia temperature 4°C and ischemia time 30 and 60 minutes or ischemia temperature 24°C and ischemia time 30 minutes, the RIN of T was higher compared with AN. However, there was no significant difference in RIN between T and AN under other treatment conditions. Conclusions: Tissue quality is adversely affected by ischemia time and ischemia temperature. Therefore, temporary ischemia time (≤15 minutes) before snap freezing is key for maintaining high-integrity RNA in HCC tissues.


Sujet(s)
Carcinome hépatocellulaire/anatomopathologie , Tumeurs du foie/anatomopathologie , ARN messager/composition chimique , Banques de tissus/normes , Carcinome hépatocellulaire/génétique , Cryoconservation , Humains , Ischémie , Tumeurs du foie/génétique , Stabilité de l'ARN , Répartition aléatoire , Manipulation d'échantillons , Température , Facteurs temps
15.
ACS Appl Mater Interfaces ; 11(13): 12838-12845, 2019 Apr 03.
Article de Anglais | MEDLINE | ID: mdl-30864773

RÉSUMÉ

Various organogel materials with either a liquid or solid surface layer have recently been designed and prepared. In this work, amphiphilic organogels (AmOG) are innovatively developed from copolymer P(PDMS-r-PEG-r-GMA) and 2,2'-diaminodiphenyldisulfide via epoxy group addition reaction and then infiltrated with amphiphilic lubricants instead of traditional hydrophilic or hydrophobic lubricants. Because of synergistic effects of hydrophilic and hydrophobic segments of amphiphilic lubricants, the AmOG surfaces showed high stability and excellent anti-icing performance. The delay in the freezing point of water was 1000 s on AmOG surfaces, which is 40 times longer as compared to the untreated hydrophilic glass surface. More importantly, low ice adhesion strength (15.1 kPa) was observed on AmOG which remained about 40 kPa even after 20 icing-deicing cycles. The novel amphiphilic organogels provide a new idea to prepare long-term anti-icing materials for practical applications.

16.
Langmuir ; 35(37): 11959-11967, 2019 09 17.
Article de Anglais | MEDLINE | ID: mdl-30912432

RÉSUMÉ

Severe water pollution has placed a heavy burden on the ecological environment on which humans rely. Effective approaches to mitigating this worldwide issue are in great demand. Here in this work, an organic-inorganic bacterial cellulose aerogel was fabricated through a freeze-drying technique and a step-by-step coating method. The as-prepared aerogel possessed an intact three-dimensional porous structure, an ultralow density, and shape recovery performance. Ag2O nanoparticles were uniformly and firmly dispersed on the cellulose skeleton, endowing the as-prepared aerogel with an excellent photocatalytic degradation property of methylene blue and great recyclability. The aerogel with zwitterionic compounds attached through the effect of silane exhibited superhydrophilicity, superoleophilicity, and underwater superoleophobicity as well as underoil superhydrophobicity, and it could separate oil/water mixtures with high efficiency. This environmentally friendly bacterial cellulose aerogel equipped with multifunctionality showed great potential for wide application in water treatment fields.


Sujet(s)
Bactéries/composition chimique , Cellulose/composition chimique , Purification de l'eau/méthodes , Gels , Oxydes/composition chimique , Composés de l'argent/composition chimique , Polluants chimiques de l'eau/composition chimique , Polluants chimiques de l'eau/isolement et purification , Mouillabilité
17.
Langmuir ; 34(50): 15425-15444, 2018 12 18.
Article de Anglais | MEDLINE | ID: mdl-30445813

RÉSUMÉ

Ice formation and accretion on surfaces is a serious economic issue in energy supply and transportation. Recent strategies for developing icephobic surfaces are intimately associated with superwettability. Commonly, the superwettability of icephobic materials depends on their surface roughness and chemical composition. This article critically categorizes the possible strategies to mitigate icing problems from daily life. The wettability and classical nucleation theories are used to characterize the icephobic surfaces. Thermodynamically, the advantages/disadvantages of superhydrophobic surfaces are discussed to explain icephobic behavior. The importance of elasticity, slippery liquid-infused porous surfaces (SLIPSs), amphiphilicity, antifreezing protein, organogels, and stimuli-responsive materials has been highlighted to induce icephobic performance. In addition, the design principles and mechanism to fabricate icephobic surfaces with superwettability are explored and summarized.

18.
Langmuir ; 34(13): 4052-4058, 2018 04 03.
Article de Anglais | MEDLINE | ID: mdl-29528662

RÉSUMÉ

High durability, low cost, and superior anti-icing and active deicing multifunctional surface coatings, especially in the extreme environment, are highly desired to inhibit and/or eliminate the detriment of icing in many fields, such as automobile, aerospace, and power transmission. Herein, we first report a facile and versatile strategy to prepare novel slippery polyols-infused porous surfaces (SPIPS's) with the inexpensive polyols as the lubricant liquids. These SPIPS's are fabricated by a spray-coating approach based on amino-modified magnetic Fe3O4 nanoparticles (MNP@NH2) and amphiphilic P(poly(ethylene glycol) methyl ether methacrylate- co-glycidyl methacrylate) copolymer covalent cross-linked hybrids, followed by infusion with various polyols. The as-prepared surface exhibits excellent antifrosting property, that is, it can greatly postpone frost formation as long as 2700 s at -18 °C. Meanwhile, differential scanning calorimetry results clearly demonstrate that SPIPS's show a remarkable freezing point depression capacity and the crystallization point of water can be decreased as low as -36.8 °C. The SPIPS also displays an extremely low ice adhesion strength (0.1 kPa) due to its unique surface characteristics. Moreover, outstanding active thermal deicing property is achieved for these slippery surfaces because of intrinsically photothermal effect of magnetic Fe3O4 nanoparticle. Hence, these results indicate that this kind of multifunctional bioinspired slippery surface, with superb stability, good cost effectiveness, and easy fabrication, can be used as a promising candidate for anti-icing and deicing applications.

19.
Langmuir ; 33(39): 10340-10350, 2017 10 03.
Article de Anglais | MEDLINE | ID: mdl-28893069

RÉSUMÉ

In this work, a novel substrate building block, magnetic Fe3O4 nanoparticles armed with dopamine molecules were developed via mussel-inspired metal-coordination bonds. Combined with glycidyl methacrylate, polydimethylsiloxane propyl ether methacrylate, and diethylenetriamine, the original silicone oil swelling slippery liquid-infused porous surfaces (SLIPS) were first prepared by reversible coordinate bonds and strong covalent bonds cross-linking process. The matrix mechanical characteristics and surface physicochemical properties were systematically investigated. Results showed that the mechanical property of copolymer matrix and surface wettability of SLIPS can be remarkably recovered, which were due to the synergistic interactions of magnetic nanoparticles' intrinsic photothermal effect, reversible Fe-catechol coordination, and diffused lubricating liquid. After irradiating with sunlamp for 2 h and sequentially healing for 10 h under ambient conditions, the crack almost disappeared under optical microscopy with 78.25% healing efficiency (HEf) of toughness, and surface slippery was completely retrieved to water droplets. The efficient self-heal of copolymer matrix (66.5% HEf after eighth cutting-healing cycle) and recovering of slipperiness (SA < 5° and 5° < SA < 17° after fourth and eighth cutting-centrifuging-healing cycles, respectively) would extend longevity of SLIPS when subjected to multiple damages. Moreover, the prepared SLIPS displayed superb self-cleaning and liquid-repellent properties to a wide range of particulate contaminants and fluids.

20.
ACS Appl Mater Interfaces ; 9(35): 30161-30170, 2017 Sep 06.
Article de Anglais | MEDLINE | ID: mdl-28805055

RÉSUMÉ

The superhydrophobic antibacterial fabrics with intelligent switchable wettability were fabricated by the cross-link reaction among pH-responsive antibacterial copolymer tethered hydroxyl groups, methylol-contained poly(ureaformaldehyde) nanoparticles (PUF NPs), and hexamethylene diisocyanate. It was found that the surface concentration of N+ were heavily influenced by acid solutions, resulting in the rapid wettability conversion from superhydrophobicity/superoleophilicity to superhydrophilicity/underwater superoleophobicity in a remarkably short time. The above responsiveness feature of coated cotton fabric contributes a prominent selective oil/water separation property, and the separation efficiency invariably remained at greater than 95% even after 20 reuse cycles, which exhibited brilliant durability. More importantly, the coated cotton fabric possessed excellent self-cleaning performance after contamination by oil and held high bactericidal rate (more than 80%) regardless of pH treatment, and thus could abate the surface biological pollution caused by bacteria proliferation. The attractive properties of the prepared smart superwetting materials shows great promise for potential application in oil/water separation from an environmental-protection perspective.


Sujet(s)
Antibactériens/composition chimique , Concentration en ions d'hydrogène , Huiles , Eau , Mouillabilité
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