Effects of size and shape on the specific heat, melting entropy and enthalpy of nanomaterials

Singh, Mahak; Lara, Sekhants'o Paul; Tlali, Spirit

doi:10.1016/j.jtusci.2016.09.011

Cited by 93 publications

(45 citation statements)

References 37 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Only a minor size reduction may be concluded in the case of TiATN–methanol. In contrast, the shift of the fusion temperature was higher in the TiATN–HCl composite, and the enthalpy of fusion significantly decreased to −40.55 Jg −1 , which may be explained by the stronger interactions and by the considerable particle size reduction of ATN [29], which was in accordance with the SEM images where less crystallization was observed. These results were also supported by the FT-IR spectra, which displayed no substantial differences between the spectra of ATN, TiATN–ethanol, and TiATN–methanol (Figure 5), whereas the appearance of a new peak at 1560 cm −1 indicating the protonation of the carbonamide group and wide low intensity peaks between 1900–2100 cm −1 and 2300–2500 cm −1 indicating the protonation of the secondary amino group were noticed in the spectrum of TiATN–HCl.…”

Section: Resultssupporting

confidence: 64%

Optimization of the Production Process and Product Quality of Titanate Nanotube–Drug Composites

et al. 2019

View full text Add to dashboard Cite

Recently, there has been an increasing interest in the application of nanotubular structures for drug delivery. There are several promising results with carbon nanotubes; however, in light of some toxicity issues, the search for alternative materials has come into focus. The objective of the present study was to investigate the influence of the applied solvent on the composite formation of titanate nanotubes (TNTs) with various drugs in order to improve their pharmacokinetics, such as solubility, stability, and bioavailability. Composites were formed by the dissolution of atenolol (ATN) and hydrochlorothiazide (HCT) in ethanol, methanol, 0.01 M hydrochloric acid or in ethanol, 1M sodium hydroxide, dimethylformamide (DMF), dimethyl sulfoxide (DMSO), respectively, and then they were mixed with a suspension of TNTs under sonication for 30 min and vacuum-dried for 24 h. The structural properties of composites were characterized by SEM, TEM, FT-IR, differential scanning calorimetry (DSC), thermogravimetric (TG) analysis, and optical contact angle (OCA) measurements. Drug release was determined from the fast disintegrating tablets using a dissolution tester coupled with a UV–Vis spectrometer. The results revealed that not only the good solubility of the drug in the applied solvent, but also the high volatility of the solvent, is necessary for an optimal composite-formation process.

show abstract

Section: Resultssupporting

confidence: 64%

Optimization of the Production Process and Product Quality of Titanate Nanotube–Drug Composites

et al. 2019

View full text Add to dashboard Cite

show abstract

“…The high storage modulus of 80 °C for the compressed P(VDF-HFP) fiber at low temperatures confirms the reinforcement effect at the molecule interfaces. It can be attributed to the restricted molecular mobility in the P(VDF-HFP) fibers by the strengthened interactions with the polymer matrix [35]. A gradual decrease of E′ is observed from −40 to 0 °C which is ascribed to the glass transition of P(VDF-HFP( [36].…”

Section: Resultsmentioning

confidence: 99%

High Electromechanical Deformation Based on Structural Beta-Phase Content and Electrostrictive Properties of Electrospun Poly(vinylidene fluoride- hexafluoropropylene) Nanofibers

2019

View full text Add to dashboard Cite

The poly(vinylidene fluoride-hexafluoropropylene) (P(VDF-HFP)) polymer based on electrostrictive polymers is essential in smart materials applications such as actuators, transducers, microelectromechanical systems, storage memory devices, energy harvesting, and biomedical sensors. The key factors for increasing the capability of electrostrictive materials are stronger dielectric properties and an increased electroactive β-phase and crystallinity of the material. In this work, the dielectric properties and microstructural β-phase in the P(VDF-HFP) polymer were improved by electrospinning conditions and thermal compression. The P(VDF-HFP) fibers from the single-step electrospinning process had a self-induced orientation and electrical poling which increased both the electroactive β-crystal phase and the spontaneous dipolar orientation simultaneously. Moreover, the P(VDF-HFP) fibers from the combined electrospinning and thermal compression achieved significantly enhanced dielectric properties and microstructural β-phase. Thermal compression clearly induced interfacial polarization by the accumulation of interfacial surface charges among two β-phase regions in the P(VDF-HFP) fibers. The grain boundaries of nanofibers frequently have high interfacial polarization, as they can trap charges migrating in an applied field. This work showed that the combination of electrospinning and thermal compression for electrostrictive P(VDF-HFP) polymers can potentially offer improved electrostriction behavior based on the dielectric permittivity and interfacial surface charge distributions for application in actuator devices, textile sensors, and nanogenerators.

show abstract

“…Due to the rapidly increase in the local temperature, monoatomic O chemisorption can occur, which leads to an incorporation of O in the Cu nano-melted region. It should be noted that nanomaterials have a lower melting point than their counterparts [56][57][58] and that low-energy Ar ion collisions (on average ≈5 eV 52 for the plasma conditions in this thesis) are able to promote Cu surface diffusion 59 . Both characteristics may facilitate the proposed degradation process.…”

Section: Discussionmentioning

confidence: 94%

Degradation of Cu nanowires in a low-reactive plasma environment

et al. 2020

View full text Add to dashboard Cite

The quest for miniaturisation of electronic devices is one of the backbones of industry 4.0 and nanomaterials are an envisaged solution capable of addressing these complex technological challenges. When subjected to synthesis and processing, nanomaterials must be able to hold pristine its initial designed properties, but occasionally, this may trigger degradation mechanisms that can impair their application by either destroying their initial morphology or deteriorating of mechanical and electrical properties. Degradation of nanomaterials under processing conditions using plasmas, ion implantation and high temperatures is up to date largely sub-notified in the literature. The degradation of single-crystal Cu nanowires when exposed to a plasma environment with residual active O is herein investigated and reported. It is shown that single-crystal Cu nanowires may degrade even in low-reactive plasma conditions by means of a vapour–solid–solid nucleation and growth mechanism.

show abstract

Effects of size and shape on the specific heat, melting entropy and enthalpy of nanomaterials

Cited by 93 publications

References 37 publications

Optimization of the Production Process and Product Quality of Titanate Nanotube–Drug Composites

Optimization of the Production Process and Product Quality of Titanate Nanotube–Drug Composites

High Electromechanical Deformation Based on Structural Beta-Phase Content and Electrostrictive Properties of Electrospun Poly(vinylidene fluoride- hexafluoropropylene) Nanofibers

Degradation of Cu nanowires in a low-reactive plasma environment

Contact Info

Product

Resources

About