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1.
Molecules ; 29(15)2024 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-39125060

RESUMO

We report a transformative epoxy system with a microalgae-derived bio-binder from hydrothermal liquefaction processing (HTL). The obtained bio-binder not only served as a curing agent for conventional epoxy resin (e.g., EPON 862), but also acted as a modifying agent to enhance the thermal and mechanical properties of the conventional epoxy resin. This game-changing epoxy/bio-binder system outperformed the conventional epoxy/hardener system in thermal stability and mechanical properties. Compared to the commercial EPON 862/EPIKURE W epoxy product, our epoxy/bio-binder system (35 wt.% bio-binder addition with respect to the epoxy) increased the temperature of 60% weight loss from 394 °C to 428 °C and the temperature of maximum decomposition rate from 382 °C to 413 °C, while the tensile, flexural, and impact performance of the cured epoxy improved in all cases by up to 64%. Our research could significantly impact the USD 38.2 billion global market of the epoxy-related industry by not only providing better thermal and mechanical performance of epoxy-based composite materials, but also simultaneously reducing the carbon footprint from the epoxy industry and relieving waste epoxy pollution.


Assuntos
Resinas Epóxi , Microalgas , Microalgas/química , Resinas Epóxi/química , Temperatura , Compostos de Epóxi/química , Resistência à Tração
2.
Sci Prog ; 104(3): 368504211029471, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34281432

RESUMO

Polymeric hybrid nanocomposites, due to improved mechanical, thermal, and electrical properties, are key factors in recent technologies. Because of anisotropic characteristics of polymeric hybrid nanocomposites, mechanical properties and their behavior are very difficult to predict. If they are fabricated with complicated woven fabric patterns, it becomes more difficult to predict. This review discusses in detail the properties and manufacturing methods of various fibers, focuses on different manufacturing, processing, and characterization techniques used for polymeric hybrid nanocomposites. Theoretical composite models and some recent advances in modeling and simulation techniques for polymer nanoparticle composites are discussed and thus this review can provide significant guidelines for the development of manufacturing, characterization, testing, modeling, and simulation techniques for high performance hybrid polymer nanocomposites as current state of art.

3.
Nanoscale Adv ; 1(5): 1693-1701, 2019 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-36134222

RESUMO

Preparation of high-quality boron nitride nanotubes (BNNTs) from commercially available stock is critical for eventual industry adoption and to perform comprehensive experimental studies of BNNTs. Separation of hexagonal boron nitride (h-BN) and BNNTs is a significant challenge, and equally so, quantification of h-BN content in mixed samples is a major challenge due to their nearly identical properties. This work introduces a simple method of quantifying h-BN content in BNNTs based on FTIR analysis. Quantification is achieved by "spiking" a BNNT sample with pure nanoscale h-BN as an internal standard. To demonstrate the efficacy of the quantification technique two BNNT enrichment methods, surfactant wrapping and centrifugation, and a novel sonication-assisted isovolumetric filtration are introduced. FTIR spectra of enriched samples show clear trends throughout the processes. We propose and demonstrate that FTIR peak ratios of the transverse and buckling modes of mixed h-BN/BNNT samples can be used to calibrate and quantify h-BN content in any BNNT sample. Hopefully, this method enables as-received BNNTs to be quantifiably enriched from low purity commercial feedstocks, enabling future development and study of BNNTs and related technology.

4.
ScientificWorldJournal ; 2014: 325783, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24719573

RESUMO

In the present study experimental and numerical investigations were carried out to predict the low velocity impact response of four symmetric configurations: 10 ply E Glass, 10 ply AS4 Carbon, and two Hybrid combinations with 1 and 2 outer plies of E Glass and 8 and 6 inner plies of Carbon. All numerical investigations were performed using commercial finite element software, LS-DYNA. The test coupons were manufactured using the low cost Heated Vacuum Assisted Resin Transfer Molding (H-VARTM©) technique. Low velocity impact testing was carried out using an Instron Dynatup 8250 impact testing machine. Standard 6 × 6 Boeing fixture was used for all impact experiments. Impact experiments were performed over progressive damage, that is, from incipient damage till complete failure of the laminate in six successive impact energy levels for each configuration. The simulation results for the impact loading were compared with the experimental results. For both nonhybrid configurations, it was observed that the simulated results were in good agreement with the experimental results, whereas, for hybrid configurations, the simulated impact response was softer than the experimental response. Maximum impact load carrying capacity was also compared for all four configurations based on their areal density. It was observed that Hybrid262 configuration has superior impact load to areal density ratio.


Assuntos
Aceleração , Modelos Teóricos , Têxteis/análise , Força Compressiva , Simulação por Computador , Dureza , Teste de Materiais , Estresse Mecânico
5.
J Phys Chem B ; 117(40): 12095-104, 2013 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-23952604

RESUMO

Understanding drug transportation and delivery mechanism from a molecular viewpoint is essential to find better treatment pathways. Despite the fact that many significant drugs such as anticancer doxorubicin and mitoxantrone are predominantly hydrophilic, an efficient methodology to deliver hydrophilic drug components is not well established. Here we explore this problem by studying "patchy" polymeric micelle assisted hydrophilic component transportation across a lipid membrane and delivery inside a biological lipid vesicle. Using the MARTINI force field as the basis, we study the interaction of polymeric micelle with DPPC lipid vesicles in detail. In order to facilitate hydrophilic drug transportation study, a primitive CG model for hydrophilic drug component is used. Extensive simulations carried out over hundreds of nanoseconds demonstrate successful encapsulation, transportation of hydrophilic components by patchy polymeric micelles. Results show the polymeric micelle releases a significant portion of hydrophilic contents inside the lipid vesicle. The present simulation study also reveals a possible mechanism for efficient hydrophilic component transportation and delivery. Insights from this study could potentially help the experimental community to design better delivery vehicles, especially for hydrophilic drug molecules.


Assuntos
Bicamadas Lipídicas/química , Micelas , Polímeros/química , 1,2-Dipalmitoilfosfatidilcolina/química , Simulação por Computador , Doxorrubicina/química , Portadores de Fármacos/química , Interações Hidrofóbicas e Hidrofílicas , Mitoxantrona/química , Modelos Moleculares
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