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1.
ACS Appl Mater Interfaces ; 16(15): 18658-18670, 2024 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-38587811

RESUMO

Three-dimensional (3D)-printed biodegradable polymer scaffolds are at the forefront of personalized constructs for bone tissue engineering. However, it remains challenging to create a biological microenvironment for bone growth. Herein, we developed a novel yet feasible approach to facilitate biomimetic mineralization via self-adaptive nanotopography, which overcomes difficulties in the surface biofunctionalization of 3D-printed polycaprolactone (PCL) scaffolds. The building blocks of self-adaptive nanotopography were PCL lamellae that formed on the 3D-printed PCL scaffold via surface-directed epitaxial crystallization and acted as a linker to nucleate and generate hydroxyapatite crystals. Accordingly, a uniform and robust mineralized layer was immobilized throughout the scaffolds, which strongly bound to the strands and had no effect on the mechanical properties of the scaffolds. In vitro cell culture experiments revealed that the resulting scaffold was biocompatible and enhanced the proliferation and osteogenic differentiation of mouse embryolous osteoblast cells. Furthermore, we demonstrated that the resulting scaffold showed a strong capability to accelerate in vivo bone regeneration using a rabbit bone defect model. This study provides valuable opportunities to enhance the application of 3D-printed scaffolds in bone repair, paving the way for translation to other orthopedic implants.


Assuntos
Osteogênese , Tecidos Suporte , Camundongos , Animais , Coelhos , Tecidos Suporte/química , Biomimética , Regeneração Óssea , Poliésteres/química , Engenharia Tecidual , Impressão Tridimensional
2.
Biomacromolecules ; 25(4): 2438-2448, 2024 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-38502912

RESUMO

The treatment of infected wounds faces substantial challenges due to the high incidence and serious infection-related complications. Natural-based hydrogel dressings with favorable antibacterial properties and strong applicability are urgently needed. Herein, we developed a composite hydrogel by constructing multiple networks and loading ciprofloxacin for infected wound healing. The hydrogel was synthesized via a Schiff base reaction between carboxymethyl chitosan and oxidized sodium alginate, followed by the polymerization of the acrylamide monomer. The resultant hydrogel dressing possessed a good self-healing ability, considerable compression strength, and reliable compression fatigue resistance. In vitro assessment showed that the composite hydrogel effectively eliminated bacteria and exhibited an excellent biocompatibility. In a model of Staphylococcus aureus-infected full-thickness wounds, wound healing was significantly accelerated without scars through the composite hydrogel by reducing wound inflammation. Overall, this study opens up a new way for developing multifunctional hydrogel wound dressings to treat wound infections.


Assuntos
Quitosana , Hidrogéis , Hidrogéis/farmacologia , Cicatrização , Antibacterianos/farmacologia , Ciprofloxacina , Bandagens
3.
Small ; : e2312135, 2024 Mar 19.
Artigo em Inglês | MEDLINE | ID: mdl-38501794

RESUMO

Carbon fiber (CF) is a potential microwave absorption (MA) material due to the strong dielectric loss. Nevertheless, owing to the high conductivity, poor impedance matching of carbon-based  materials results in limited MA performance. How to solve this problem and achieve excellent MA performance remains a principal challenge. Herein, taking full advantage of CF and excellent impedance matching of bimetallic metal-organic frameworks (MOF) derivatives layer, an excellent microwave absorber based on micron-scale 1D CF and NiCoMOF (CF@NiCoMOF-800) is developed. After adjusting the oxygen vacancies of the bimetallic MOF, the resultant microwave absorber presented excellent MA properties including the minimum reflection loss (RLmin ) of -80.63 dB and wide effective absorption bandwidth (EAB) of 8.01 GHz when its mass percent is only 5 wt.% and the thickness is 2.59 mm. Simultaneously, the mechanical properties of the epoxy resin (EP)-based coating with this microwave absorber are effectively improved. The hardness (H), elastic modulus (E), bending strength, and compressive strength of CF@NiCoMOF-800/EP coating are 334 MPa, 5.56 GPa, 82.2 MPa, and 135.8 MPa, which is 38%, 15%, 106% and 53% higher than EP coating. This work provides a promising solution for carbon materials achieving excellent MA properties and mechanical properties.

4.
Adv Healthc Mater ; : e2304178, 2024 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-38490686

RESUMO

Structural engineering is an appealing means to modulate osteogenesis without the intervention of exogenous cells or therapeutic agents. In this work, a novel 3D scaffold with anisotropic micropores and nanotopographical patterns is developed. Scaffolds with oriented pores are fabricated via the selective extraction of water-soluble polyethylene oxide from its poly(ε-caprolactone) co-continuous mixture and uniaxial stretching. The plate apatite-like lamellae are subsequently hatched on the pore walls through surface-induced epitaxial crystallization. Such a unique geometric architecture yields a synergistic effect on the osteogenic capability. The prepared scaffold leads to a 19.2% and 128.0% increase in the alkaline phosphatase activity of rat bone mesenchymal stem cells compared to that of the scaffolds with only oriented pores and only nanotopographical patterns, respectively. It also induces the greatest upregulation of osteogenic-related gene expression in vitro. The cranial defect repair results demonstrate that the prepared scaffold effectively promotes new bone regeneration, as indicated by a 350% increase in collagen I expression in vivo compared to the isotropic porous scaffold without surface nanotopology after implantation for 14 weeks. Overall, this work provides geometric motifs for the transduction of biophysical cues in 3D porous scaffolds, which is a promising option for tissue engineering applications.

5.
Adv Healthc Mater ; : e2303549, 2024 Feb 09.
Artigo em Inglês | MEDLINE | ID: mdl-38333940

RESUMO

Periodontitis is a common oral disease accompanied by inflammatory bone loss. The pathological characteristics of periodontitis usually accompany an imbalance in the periodontal immune microenvironment, leading to difficulty in bone regeneration. Therefore, effective treatment strategies are needed to modulate the immune environment in order to treat periodontitis. Here, we developed a highly-oriented periodic lamellae poly(ε-caprolactone) electrospun nanofibers (PLN) by surface-directed epitaxial crystallization. Our in vitro results showed that the PLN could precisely modulate macrophage polarization toward the M2 phenotype. Macrophages polarized by PLN significantly enhanced the migration and osteogenic differentiation of BMSCs. Notably, results suggested that the topographical cues presented by PLN can modulate macrophage polarization by activating YAP, which reciprocally inhibits the NF-κB signaling pathway. The in vivo results indicated that PLN can inhibit inflammatory bone loss and facilitate bone regeneration in periodontitis. Our findings suggest that topographical nanofibers with periodic lamellae is a promising strategy for modulating immune environment to treat inflammatory bone loss in periodontitis. This article is protected by copyright. All rights reserved.

6.
Pharmaceutics ; 16(2)2024 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-38399258

RESUMO

Currently, biomineralization is widely used as a surface modification approach to obtain ideal material surfaces with complex hierarchical nanostructures, morphologies, unique biological functions, and categorized organizations. The fabrication of biomineralized coating for the surfaces of scaffolds, especially synthetic polymer scaffolds, can alter surface characteristics, provide a favorable microenvironment, release various bioactive substances, regulate the cellular behaviors of osteoblasts, and promote bone regeneration after implantation. However, the biomineralized coating fabricated by immersion in a simulated body fluid has the disadvantages of non-uniformity, instability, and limited capacity to act as an effective reservoir of bioactive ions for bone regeneration. In this study, in order to promote the osteoinductivity of 3D-printed PCL scaffolds, we optimized the surface biomineralization procedure by nano-topographical guidance. Compared with biomineralized coating constructed by the conventional method, the nano-topographically guided biomineralized coating possessed more mineral substances and firmly existed on the surface of scaffolds. Additionally, nano-topographically guided biomineralized coating possessed better protein adsorption and ion release capacities. To this end, the present work also demonstrated that nano-topographically guided biomineralized coating on the surface of 3D-printed PCL scaffolds can regulate the cellular behaviors of USCs, guide the osteogenic differentiation of USCs, and provide a biomimetic microenvironment for bone regeneration.

7.
Int J Biol Macromol ; 261(Pt 2): 129829, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38296134

RESUMO

Three-dimensional interpenetrating and hierarchically porous carbon material is an efficient catalyst support in water remediation and it is still a daunting challenge to establish the relationship between hierarchically porous structure and catalytic degradation performance. Herein, a highly porous silica (SiO2)/cellulose-based carbon aerogel with iron-based catalyst (FexOy) was fabricated by in-situ synthesis, freeze-drying and pyrolysis, where the addition of SiO2 induced the hierarchically porous morphology and three-dimensional interpenetrating sheet-like network with nitrogen doping. The destruction of cellulose crystalline structure by SiO2 and the iron-catalyzed breakdown of glycosidic bonds synergistically facilitated the formation of electron-rich graphite-like carbon skeleton. The unique microstructure is confirmed to be favorable for the diffusion of reactants and electron transport during catalytic process, thus boosting the catalytic degradation performance of carbon aerogels. As a result, the catalytic degradation efficiency of tetracycline under light irradiation by adding only 5 mg of FexOy/SiO2 cellulose carbon aerogels was as high as 90 % within 60 min, demonstrating the synergistic effect of photocatalysis and Fenton reaction. This ingenious structure design provides new insight into the relationship between hierarchically porous structure of carbon aerogels and their catalytic degradation performance, and opens a new avenue to develop cellulose-based carbon aerogel catalysts with efficient catalytic performance.


Assuntos
Carbono , Compostos Heterocíclicos , Carbono/química , Ferro/química , Dióxido de Silício , Celulose/química , Porosidade , Tetraciclina/química , Antibacterianos , Catálise
8.
ACS Appl Mater Interfaces ; 16(5): 6462-6473, 2024 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-38266189

RESUMO

The peelable microwave absorption (MA) coating with reversible adhesion for stable presence on substrates and easy release without any residuals is highly desired in temporary electromagnetic protection, which can quickly enter and disengage the electromagnetic protection state according to the real-time changeable harsh surroundings. On the contrary, with the incorporation of abundant absorbent to achieve excellent MA ability, the tunable adhesion and sufficient cohesion are extremely challenging to fulfill the above requirement. The reported peelable coatings still have problems in controlling adhesion/cohesion strength and coating release, facing substantial residuals after peeling even using complex chemical modification or abundant additives. Herein, a peelable MA coating based on the block characteristics of polar and nonpolar segments of poly(styrene-(ethylene-co-butylene)-styrene) (SEBS) is successfully developed. The polyaniline-decorated carbon nanotube as a microwave absorber plays a positive influence on the adhesion/cohesion of the coating due to bonding interaction. The competitive effective absorption bandwidth (EAB) of 8.8 GHz and controllable yet reversible adhesion release on various substrates and complex surfaces have been achieved. The reusability endows peelable MA coating with 93% retention of EAB even after ten coating-peeling cycles. The coating with excellent chemical and adhesion stability can effectively protect substrates from salt/acid/alkali corrosion, showing over 98% retention of EAB even after 8 h of accelerated corrosion. Our peelable MA coating via a general yet reliable approach provides a prospect for temporary electromagnetic protection.

9.
ACS Appl Mater Interfaces ; 15(34): 40954-40962, 2023 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-37584965

RESUMO

Given the rapid developments in modern devices, there is an urgent need for shape-memory polymer composites (SMPCs) in soft robots and other fields. However, it remains a challenge to endow SMPCs with both a reconfigurable permanent shape and a locally reversible shape transformation. Herein, a dynamic cross-linked network was facilely constructed in carbon nanotube/ethylene vinyl acetate copolymer (CNT/EVA) composites by designing the molecular structure of EVA. The CNT/EVA composite with 0.05 wt % CNT realized a steady-state temperature of ∼75 °C under 0.11 W/cm2 light intensity, which gave rise to remote actuation behavior. The dynamic cross-linked network along with a wide melting temperature offered opportunities for chemical and physical programming, thus realizing the achievement of the programmable three-dimensional (3D) structure and locally reversible actuation. Specifically, the CNT/EVA composite exhibited a superior permanent shape reconfiguration by activating the dynamic cross-linked network at 140 °C. The composite also showed a high reversible deformation rate of 11.1%. These features endowed the composites with the capability of transformation to 3D structure as well as locally reversible actuation performance. This work provides an attractive guideline for the future design of SMPCs with sophisticated structures and actuation capability.

10.
ACS Appl Mater Interfaces ; 15(32): 38867-38877, 2023 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-37542460

RESUMO

Multilayer structures are not only applied to manipulate properties of synthetic polymer materials such as rainbow films and barrier films but also widely discovered in natural materials like nacre. In this work, in situ formation of an interconnected multi-nanolayer (IMN) structure in poly(butylene adipate-co-terephthalate) (PBAT)/poly(butylene succinate) (PBS) cocontinuous blends is designed by an extensional flow field during a "casting-thermal stretching" process, combining the properties of two components to a large extent. Hierarchical structures including phase morphology, crystal structure, and lamellar crystals in IMN films have been revealed, which clearly identifies the crucial role of extensional flow. The oriented PBAT phase in the IMN structure can be beneficial to the epitaxial growth of PBS crystals onto the PBAT nanolayers, thus improving interfacial adhesions. Furthermore, intense extensional stress can also promote crystallinity and thicken the lamellar structure. Given such distinct features in the fully biodegradable films, a simultaneous enhancement in tear strength, tensile strength, and puncture resistance has been achieved. To the best of our knowledge, the tear strength of IMN films about 285.9 kN/m is the highest level in the previous works of this system. Moreover, the proposed fabrication way of the IMN structure is facile and scalable, which is highly expected to be an efficient strategy for development of structured biodegradable polymers with excellent comprehensive properties.

11.
ACS Nano ; 17(14): 14114-14122, 2023 Jul 25.
Artigo em Inglês | MEDLINE | ID: mdl-37405783

RESUMO

Conventional polymer/ceramic composite solid-state electrolytes (CPEs) have limitations in inhibiting lithium dendrite growth and fail to meet the contradictory requirements of anodes and cathodes. Herein, an asymmetrical poly(vinylidene fluoride) (PVDF)-PbZrxTi1-xO3 (PZT) CPE was prepared. The CPE incorporates high dielectric PZT nanoparticles, which enrich a dense thin layer on the anode side, making their dipole ends strongly electronegative. This attracts lithium ions (Li+) at the PVDF-PZT interface to transport through dipolar channels and promotes the dissociation of lithium salts into free Li+. Consequently, the CPE enables homogeneous lithium plating and suppresses dendrite growth. Meanwhile, the PVDF-enriched region at the cathode side ensures intermediate contact with positive active materials. Therefore, Li/PVDF-PZT CPE/Li symmetrical cells exhibit a stable cycling performance exceeding 1900 h at 0.1 mA cm-2 at 25 °C, outperforming Li/PVDF solid-state electrolyte/Li cells that fail after 120 h. The LiNi0.8Co0.1Mo0.1O2/PVDF-PZT CPE/Li cells show low interfacial impedances and maintain stable cycling performance for 500 cycles with a capacity retention of 86.2% at 0.5 C and 25 °C. This study introduces a strategy utilizing dielectric ceramics to construct dipolar channels, providing a uniform Li+ transport mechanism and inhibiting dendrite growth.

12.
ACS Biomater Sci Eng ; 9(7): 4431-4441, 2023 07 10.
Artigo em Inglês | MEDLINE | ID: mdl-37452570

RESUMO

Periodontitis is a worldwide bacterial infectious disease, resulting in the resorption of tooth-supporting structures. Biodegradable polymeric microspheres are emerging as an appealing local therapy candidate for periodontal defect regeneration but suffer from tedious procedures and low yields. Herein, we developed a facile yet scalable approach to prepare polylactide composite microspheres with outstanding drug-loading capability. It was realized by blending equimolar polylactide enantiomers at the temperature between the melting point of homocrystallites and stereocomplex (sc) crystallites, enabling the precipitation of sc crystallites in the form of microspheres. Meanwhile, epigallocatechin gallate (EGCG) and nano-hydroxyapatite were encapsulated in the microspheres in the designated amount. Such an assembly allowed the fast and sustained release of EGCG and Ca2+ ions. The resultant hybrid composite microspheres not only exhibited strong antimicrobial activity against typical oral pathogens (Porphyromonas gingivalis and Enterococcus faecalis), but also directly promoted osteogenic differentiation of periodontal ligament stem cells with good cytocompatibility. These dual-functional composite microspheres offer a desired drug delivery platform to address the practical needs for periodontitis treatment.


Assuntos
Osteogênese , Ligamento Periodontal , Microesferas , Células-Tronco , Diferenciação Celular
13.
Biomacromolecules ; 24(7): 3127-3137, 2023 07 10.
Artigo em Inglês | MEDLINE | ID: mdl-37276461

RESUMO

The relationship between the density of the entangled amorphous network and the ductility of oriented poly(l-lactide) (PLLA) films is explored based on the preferential hydrolysis of the amorphous regions in phosphate buffer solution (PBS). PLLA films with a balance of ductility and stiffness have been prepared by the "casting-annealing stretching" based on mechanical rejuvenation, and the structural evolution and mechanical properties at different hydrolysis durations have been identified. Various stages are found during the transition of ductility to brittleness for hydrolyzed PLLA films. First, the elongation at break for hydrolyzed PLLA films remains unchanged in the first stage of hydrolysis and then gradually decreases. Eventually, the films turn to be brittle in the third stage. The strain-hardening modulus (GR) of the hydrolyzed films is utilized to reflect the density of the entangled amorphous network, and a gradual decrease of GR with hydrolysis time indicates the decisive role of the amorphous entanglement network in the mechanical rejuvenation-induced ductility of PLLA. The quantitative relationship between the entangled amorphous network and the stress-induced ductility of PLLA films is revealed. The dependence of deformation behavior on entangled amorphous network density is closely correlated to activated primary structure during deformation. The intact chain network plays a crucial role in sufficiently activating the primary structure to yield and disentanglement during the subsequent necking. These findings could advance the understanding of the PLLA's ductility induced by mechanical rejuvenation and offer guidance for awakening the intrinsic toughness of PLLA.


Assuntos
Poliésteres , Poliésteres/química , Resistência à Tração , Hidrólise
14.
ACS Macro Lett ; 12(7): 880-887, 2023 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-37343235

RESUMO

Cellulose-based dielectrics with attractive dielectric performance are promising candidates to develop eco-friendly electrostatic energy storage devices. Herein, all-cellulose composite films with superior dielectric constant were fabricated by manipulating the dissolution temperature of native cellulose, where we revealed the relationship among the hierarchical microstructure of the crystalline structure, the hydrogen bonding network, the relaxation behavior at a molecular level, and the dielectric performance of the cellulose film. The coexistence of cellulose I and cellulose II led to a weakened hydrogen bonding network and unstable C6 conformations. The increased mobility of cellulose chains in the cellulose I-amorphous interphase enhanced the dielectric relaxation strength of side groups and localized main chains. As a result, the as-prepared all-cellulose composite films exhibited a fascinating dielectric constant of as high as 13.9 at 1000 Hz. This work proposed here provides a significant step toward fundamentally understanding the dielectric relaxation of cellulose, thus developing high-performance and eco-friendly cellulose-based film capacitors.

15.
J Colloid Interface Sci ; 649: 501-509, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37356151

RESUMO

The impedance matching performance of carbon nanotubes (CNTs) can be effectively enhanced by developing a uniform magnetic impedance matching layer, which can take on critical significance in achieving the desirable microwave absorption (MA) performance. To obtain a uniform coating of Nickel (Ni) nanoparticles on CNTs, several methods have been developed (e.g., the γ-irradiation technique, electroless deposition, as well as microwave welding method). However, the intricate and complicated conditions of the above-mentioned methods limit their wide application. Therefore, controlling the distribution of Ni nanoparticles with the aid of a concise and effective method remains a great challenge. Herein, in view of the uniform dispersion effect of polyvinylpyrrolidone (PVP) on CNTs and its complexation with Ni ions, uniform coating of Ni nanoparticles on CNTs is well developed after it is introduced in the hydrothermal process. The prepared Ni/CNTs composites exhibited excellent MA performance in comparison with those of reported Ni/CNTs composites for the ideal impedance matching performance and microwave attenuation ability. When the filler content was only 15 wt%, the minimum reflection loss (RLmin) reached -39.5 dB, and the effective bandwidth (EB) with RL < -10 dB reached 5.2 GHz at the thickness of 1.15 mm. A scalable strategy of regulating the distribution of Ni nanoparticles and preparing a lightweight microwave absorber based on CNTs was developed in this study, which can serve as a vital guideline for preparing novel MA composite materials.

16.
ACS Appl Mater Interfaces ; 15(19): 23701-23710, 2023 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-37140941

RESUMO

Polypropylene (PP) serves as an excellent commercialized polymer dielectric film owing to its high breakdown strength, excellent self-healing ability, and flexibility. However, its low dielectric constant causes the large volume of the capacitor. Constructing multicomponent polypropylene-based all-organic polymer dielectric films is a facile strategy for achieving high energy density and efficiency simultaneously. Thereinto, the interfaces between the components become the key factors that determine the energy storage performance of the dielectric films. In this work, we propose to fabricate high-performance polyamide 513 (PA513)/PP all-organic polymer dielectric films via the construction of abundant well-aligned and isolated nanofibrillar interfaces. Laudably, a significant enhancement in the breakdown strength is achieved from 573.1 MV/m of pure PP to 692.3 MV/m with 5 wt % of PA513 nanofibrils. Besides, a maximum discharge energy density of about 4.4 J/cm2 is realized with 20 wt % of PA513 nanofibrils, which is about 1.6-folds higher than pure PP. Simultaneously, the energy efficiency of samples with modulated interfaces maintains higher than 80% up to 600 MV/m, which is much higher than pure PP of about 40.7% at 550 MV/m. This work provides a new strategy to fabricate high-performance multicomponent all-organic polymer dielectric films on an industrial scale.

17.
ACS Appl Mater Interfaces ; 15(21): 25403-25416, 2023 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-37202852

RESUMO

Senile osteoporotic fracture has aroused increasing attention due to high morbidity and mortality. However, to date, there is no effective therapeutic approach available. Senile osteoporosis is characterized by impaired osteogenesis and angiogenesis, osteoporotic fracture repair could also be promoted by enhancing osteogenesis and angiogenesis. Tetrahedral framework nucleic acids (tFNAs) are a multifunctional nanomaterial that have recently been extensively used in biomedical fields, which could enhance osteogenesis and angiogenesis in vitro. Therefore, we applied tFNAs to intact and femoral fractural senile osteoporotic mice, respectively, to evaluate the effects of tFNAs on senile osteoporosis and osteoporotic fracture repair regarding the osteogenesis and angiogenesis of the callus at the early healing stages and to initially explore the potential mechanism. The outcomes showed that tFNAs had no significant effects on the osteogenesis and angiogenesis of the femur and mandible in intact senile osteoporotic mice within 3 weeks after tFNA treatment, while tFNAs could promote osteogenesis and angiogenesis of callus in osteoporotic fracture repair, which may be regulated by a FoxO1-related SIRT1 pathway. In conclusion, tFNAs could promote senile osteoporotic fracture repair by enhancing osteogenesis and angiogenesis, offering a new strategy for the treatment of senile osteoporotic fracture.


Assuntos
Ácidos Nucleicos , Osteoporose , Fraturas por Osteoporose , Camundongos , Animais , Osteogênese , Fraturas por Osteoporose/terapia , Consolidação da Fratura , Ácidos Nucleicos/farmacologia , Osteoporose/tratamento farmacológico
18.
J Biomed Mater Res B Appl Biomater ; 111(1): 26-37, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-35809250

RESUMO

Vitamin E (VE) is currently an approved antioxidant to improve the oxidation stability of highly crosslinked ultrahigh molecular weight polyethylene (UHMWPE) insert used commercially in total joint arthroplasty. However, the decrease in crosslink density caused by VE reduces wear resistance of UHMWPE, showing an uncoordinated challenge. In this work, we hypothesized that D-sorbitol (DS) as a secondary antioxidant can improve the antioxidant efficacy of VE on chemically crosslinked UHMWPE. The combined effect of VE and DS on oxidation stability of UHMWPE was investigated at a set of controlled hybrid antioxidant content. The hybrid antioxidant strategy showed significantly synergistic enhancement on the oxidation stability of chemically crosslinked UHMWPE compared with the single VE strategy. More strikingly, the crosslink density of the blends with hybrid antioxidants stayed at a high level since DS is not sensitive to crosslinking. The relationships between oxidation stability, mechanical properties, crosslink density, and crystallinity were investigated, by which the clinically relevant overall performance of UHMWPE was optimized. This work provides a leading-edge design mean for the development of joint bearings.


Assuntos
Antioxidantes , Polietilenos , Antioxidantes/química , Peso Molecular , Teste de Materiais , Polietilenos/química , Vitamina E/química
19.
J Colloid Interface Sci ; 630(Pt A): 772-782, 2023 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-36283265

RESUMO

Immobilizing catalyst system faces the challenge of balancing catalysts stability and exposure of active site in water treatment. In this study, a novel in-situ synthesis of monoclinic phase of titanium dioxide (TiO2(B)) in cellulose-derived carbon aerogel (TCA) is proposed for processing multi-task in water treatment. The homogeneous gelation reaction supported the high dispersion of TiO2(B) in carbon skeleton. Meanwhile, TiO2 acts as crosslinker to reinforce cellulose network, then the grain refinement of amorphous TiO2 is limited to obtain TiO2(B) during carbonization. Benefiting from the reinforced structure, TCA remains the porous structure after carbonization and exposes more adsorption site than carbon aerogel blended with anatase particles (ACA). The adsorption performance of TCA are 837.3 mg/g, 1156.2 mg/g and 512.6 mg/g on methylene blue, malachite green and crystal violet, respectively. Compared with ACA, the superior interaction between TiO2 and graphite-like carbon improves the degradation rate of tetracycline from 1.3 × 10-3 min-1 to 8.6 × 10-3 min-1, and maintains the degradation efficiency in 3 rounds cyclic test. Besides, TCA also exhibits nearly twice to ACA on absorption capacity of different oil. This facile in-situ synthesis method offers a new insight in fabricating carbon aerogel immobilized photocatalysts system for multi-task in water treatment.


Assuntos
Nanocompostos , Purificação da Água , Carbono , Titânio/química , Nanocompostos/química , Celulose/química , Catálise
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