Manila Chieruzzi | University of Perugia, Italy (original) (raw)

Papers by Manila Chieruzzi

Journal of heat transfer, Jan 10, 2018

In this study, different nanofluids (NFs) were developed by mixing a molten salt mixture (60% NaN... more In this study, different nanofluids (NFs) were developed by mixing a molten salt mixture (60% NaNO3–40% KNO3) with 1.0 wt % of silica–alumina nanoparticles using different methods. These NFs can be used as thermal energy storage materials in concentrating solar plants with a reduction of storage material if the thermal properties of the base fluid are increased. New mixing procedures without sonication were introduced with the aim to avoid the sonication step and to allow the production of a greater amount of NF with a procedure potentially more suitable for large-scale productions. For this purpose, two mechanical mixers and a magnetic stirrer were used. Each NF was prepared in aqueous solution with a concentration of 100 g/l. The effect of different concentrations (300 g/l and 500 g/l) was also studied with the most effective mixer. Specific heat, melting temperature, and latent heat were measured by means of differential scanning calorimeter. Thermal conductivity and diffusivity in the solid state were also evaluated. The results show that the highest increase of the specific heat was obtained with 100 g/l both in solid (up to 31%) and in liquid phase (up to 14%) with the two mechanical mixers. The same NFs also showed higher amount of stored heat. An increase in thermal conductivity and diffusivity was also detected for high solution concentrations with a maximum of 25% and 47%, respectively. Scanning electron microscopy (SEM) and energy-dispersive X-ray analyses revealed that the grain size in the NFs is much smaller than in the salt mixture, especially for the NF showing the highest thermal properties increase, and a better nanoparticles distribution is achieved with the lowest concentration. NFs with enhanced thermal properties can be synthesized in a cost-effective form in high concentrated aqueous solutions by using mechanical mixers.

Composites Part A: Applied Science and Manufacturing, 2013

The thermal stability of nanocomposites based on unsaturated polyester resin (UP) and montmorillo... more The thermal stability of nanocomposites based on unsaturated polyester resin (UP) and montmorillonite (MMT) clays is reported. The coefficients of thermal expansion (CTE) of both neat resin and nanocomposites with various concentrations of MMT were measured and it was found that the incorporation of clay particles reduced the CTE of the polyester resin. This reduction results greater at the lower MMT concentration tested (5 wt.%). Calorimetric tests also showed that the presence of nanoclays affects the kinetics of the curing reaction and the final degree of reaction reached by the unsaturated polyester resin. Bending and tensile tests revealed that higher percentages of MMT induced higher Young's modulus while the introduction of a viscosity reducer resulted in worst mechanical performances. The fragile behaviour observed for the formulations with higher nanoclay content were confirmed by the typical cleavage surfaces of the fracture borders observed by scanning electron microscopy.

Solar Energy, 2018

Abstract Clear-sky conditions are an essential need to allow proper high-temperature solar cookin... more Abstract Clear-sky conditions are an essential need to allow proper high-temperature solar cooking. Moreover, it is not an easy task to accomplish evening cooking, especially during wintertime when solar radiation is available only for a few hours. A solution to bypass these drawbacks lies in adopting a cooker provided with a thermal storage unit. The storage unit proposed in this work is a double-walled vessel composed by two stainless steel cylindrical pots assembled concentrically. The annular space between the pots was loaded with 4 kg of phase change material (PCM) based on a ternary mixture of nitrite and nitrate salts (solar salt: 53 wt% KNO3, 40 wt% NaNO2, 7 wt% NaNO3). The thermal storage unit was characterized by means of a test rig including a high-concentration-ratio (10.78) solar box cooker. Four different sets of 14 experimental tests, divided into a heating and a cooling phase, were carried out to assess the performance of the solar cooker with the storage unit. It was found that the PCM thermal storage significantly improves the load thermal stabilization when solar radiation is not available: the load cooling time in the range 170–130 °C was determined to be from 65.12% to 107.98% higher than that without the solar-salt-based PCM thermal storage, proving the effectiveness of the proposed solution.

Materials science & engineering. C, Materials for biological applications, 2019

The study evaluated the effects of 4 wt% nanohydroxyapatite (HA), 6 wt% zinc l-carnosine (MDA) an... more The study evaluated the effects of 4 wt% nanohydroxyapatite (HA), 6 wt% zinc l-carnosine (MDA) and 1.5 wt% Ciprofloxacin (AB) on the mechanical, thermal and biological properties of glass ionomer cements (GIC). Filler and additive concentrations were selected after a previous study had tested single components and different percentages. Specimens included five silicon molds of each GIC cement for all tests. They were stored at room temperature for 24 h from specimen collection to analysis. Mechanical tests, calorimetric analysis, morphological investigation, antibacterial and cell viability assays were conducted. One-way analysis of variance (ANOVA) was used for data analysis with significance set at p < 0.05. Adding HA, MDA and AB to GICs modified their thermal, mechanical and microbiological properties. Polymerization increased. A slight decrease in the compressive strength of modified GICs was observed in dry condition (p < 0.05). Cement extracts affected cell viability in ...

Journal of Heat Transfer, 2018

Solar Energy Materials and Solar Cells, 2017

Molten salts as phase change materials (PCMs) can be used as thermal storage media in concentrate... more Molten salts as phase change materials (PCMs) can be used as thermal storage media in concentrated solar power (CSP) plants. The addition of nanoparticles into a base fluid (producing the so called nanofluid) can enhance its thermal properties. The most common technique involves the use of water. We present a new procedure based on high temperature mixing. In particular, different nanofluids were developed by mixing NaNO 3-KNO 3 (60-40 wt %) solar salt with 1.0 wt% of SiO 2 , Al 2 O 3 and a mix of SiO 2 /Al 2 O 3 nanoparticles at 300°C using a twin screw micro-compounder. The effect of different screw speeds (100 and 200 rpm) and mixing times (15 and 30 min) were studied. The results showed that the nanoparticles induce an increase of the heat of fusion of 1.5-7.4% while the onset temperatures decrease for all the nanofluids independently from the processing conditions (up to 9.7°C). Moreover, an increase in the specific heat (Cp) is recorded mainly for the nanofluid with SiO 2 /Al 2 O 3 with a maximum of 52.1% in solid phase and 18.6% in liquid phase after 30 min of mixing at 200 rpm. The same nanofluid showed the highest stored heat. Particle aggregation into clusters in solid state was detected by scanning electron microscopy (SEM) but smaller aggregates resulted for higher mixing times and screw speed related to the highest Cp. Moreover, smaller grains in the nanofluids were detected with respect to the base salt morphology. Thus, the nanofluid produced with SiO 2 /Al 2 O 3 nanoparticles at 200 rpm for 30 min gives the best overall performances. This work showed that nanofluids with enhanced thermal properties can be obtained with an innovative mixing process directly at high temperature, eliminating the water evaporation step.

Materials Science and Engineering: C, 2017

The aim of this work was to evaluate the stress distribution inside endodontically treated teeth ... more The aim of this work was to evaluate the stress distribution inside endodontically treated teeth restored with different posts (glass fibre, carbon fibre and steel posts) under different loading conditions by using a 3D-finite element analysis. The effect of masticatory and impact forces on teeth with different degrees of bone loss was analysed. The model consists of: dentine, post, cement, gutta-percha, core and crown. Four simulations were conducted with two static forces (170 N horizontal and 100 N oblique) and two sections constrained: 1 mm (alveolar bone position in a normal periodontium) and 6 mm (middle of root) below the crown. Von Mises and the principal stresses were evaluated and analysed with a 3-way ANOVA and Tukey test (=0.05) and the effect of fibre percentage analysed. Significant differences were found among the stress values for all conditions (p<0.05). Impact load was always responsible for the most critical situation especially when the bone loss was more evident. The system with steel posts showed the highest principal stresses at the post-cement interface with horizontal load and top constraints (compressive stress of 121 MPa and tensile stress of 115 MPa). The use of glass posts provides a more homogeneous behaviour of the system with lower stresses. Higher fibre percentages gave higher stress in the posts. Moreover, larger bone losses are responsible for important increase in stress. Thus, this work demonstrated that periodontal disease has an important role in the success of tooth restoration after endodontic therapy, influencing the choice of post material and depth.

Nanomaterials, 2016

The tissue engineering (TE) of dental oral tissue is facing significant changes in clinical treat... more The tissue engineering (TE) of dental oral tissue is facing significant changes in clinical treatments in dentistry. TE is based on a stem cell, signaling molecule, and scaffold triad that must be known and calibrated with attention to specific sectors in dentistry. This review article shows a summary of micro-and nanomorphological characteristics of dental tissues, of stem cells available in the oral region, of signaling molecules usable in TE, and of scaffolds available to guide partial or total reconstruction of hard, soft, periodontal, and bone tissues. Some scaffoldless techniques used in TE are also presented. Then actual and future roles of nanotechnologies about TE in dentistry are presented.

The unsatured polyester/clay nanocomposites show better thermal and mechanical properties compare... more The unsatured polyester/clay nanocomposites show better thermal and mechanical properties compared to traditional composites. They can be applied as new materials in the automotive sector and particularly in advanced areas such as aircraft and renewable energy. In these cases, one of the most required features of these types of materials is the dimensional stability or possession of a low thermal expansion coefficient (CTE). The dimensional stability of nanocomposites based on unsatured polyester resin (UP) with various concentrations of montmorillonite (MMT) clays has been investigated. The thermal expansion coefficient of both pure polyester resin and unsatured nanocomposites was measured using a thermo-mechanical analyzer (TMA) and it was found that the incorporation of clay particles reduced the CTE of pure polyester resin. This reduction results greater at low MMT concentrations (5 wt%) compared with higher concentrations (10 wt%). The distribution of the two different type of ...

Microscopy and Microanalysis, 2015

The inflammatory resorption of dental root apex (i.e., the process of removal of cementum and/or ... more The inflammatory resorption of dental root apex (i.e., the process of removal of cementum and/or dentine through the activity of resorbing cells) may show different configurations and damage the apical root structure. As knowing the morphology of resorption areas of human teeth is essential for the success of endodontic treatments, we investigated the apical resorption by scanning electron microscopy, focusing on roots with granulomas. A total of 30 teeth (with penetrating carious lesions and chronic periapical lesions) were examined, the apical third of the roots were removed and analyzed to estimate periforaminal and foraminal resorption, shape and morphology of foramen resorption, centering of the periforaminal resorption area, and diameters of each apical foramen. Periforaminal resorption was present in all samples, whereas foraminal resorption was present in 92% of cases (mainly funnel shaped). Lacunae were observed in the foraminal resorption area with an average diameter of 3...

High temperature nanofluids were obtained with the addition of different kind of nanoparticles (1... more High temperature nanofluids were obtained with the addition of different kind of nanoparticles (1%wt) to a binary salt (NaNO3-KNO3 with 60:40 ratio) in order to obtain a heat capacity enhancement of the fluid used for thermal storage. The nanoparticles added were: silica, alumina, titania and a mixture of silica-alumina (86-14). Two different methodologies for preparation of nanofluids were adopted. With the first one 198 mg of molten salt and 2 mg of nanoparticles were dissolved in 20 ml of distilled water. The solution was then sonicated for 100 min (same procedure for the base salt). The water solution was then evaporated on a hot plate at 200°C. In the second preparation method, the binary salt (19.9 g) was directly mixed with nanoparticles (0.2 g) in a twin screw micro-compounder at high temperature (300°C) for 30 min and 100-200 rpm. The nanofluids obtained with the two methods were then subjected to DSC analysis. The method adopted was: 5 min at 150°C, heating form 150°C to 3...

Nanoscale research letters, 2015

In this study different nanofluids with phase change behavior were developed by mixing a molten s... more In this study different nanofluids with phase change behavior were developed by mixing a molten salt base fluid (KNO3 selected as phase change material) with nanoparticles using the direct synthesis method. The thermal properties of the nanofluids obtained were investigated. Following the improvement in the specific heat achieved, these nanofluids can be used in concentrating solar plants with a reduction of storage material. The nanoparticles used (1.0 wt.%) were silica (SiO2), alumina (Al2O3), and a mix of silica-alumina (SiO2-Al2O3) with an average diameter of 7, 13, and 2-200 nm respectively. Each nanofluid was prepared in water solution, sonicated, and evaporated. Measurements of the thermophysical properties were performed by DSC analysis, and the dispersion of the nanoparticles was analyzed by SEM microscopy. The results obtained show that the addition of 1.0 wt.% of nanoparticles to the base salt increases the specific heat of about 5-10 % in solid phase and of 6 % in liquid...

Oral Surgery, Oral Medicine, Oral Pathology, Oral Radiology, and Endodontology, 2008

The purpose of this study was to evaluate the amounts of debris and smear layer remaining on cana... more The purpose of this study was to evaluate the amounts of debris and smear layer remaining on canal walls after preparation with ProTaper and Hero Shaper instruments in combination with NaOCl and EDTA irrigation in curved root canals. Study design. A total of 55 root canals were randomly divided into 2 instrumentation groups of 20 canals each and 1 negative control group of 15 canals. The canals in each of the 2 instrumentation groups were prepared with ProTaper or Hero Shaper instruments. Irrigation was performed with 5% NaOCl and 17% EDTA solutions. The control group was not instrumented. The remaining debris and smear layer were evaluated from scanning electron photomicrographs at ϫ200 and ϫ1,000 magnification taken in the coronal, middle, and apical thirds of the canals at both inner and outer canal walls. A 5-category scoring system for debris and smear layer was used. Statistical analysis was carried out using the Kruskal-Wallis and Mann-Whitney rank sum tests. Results. Completely clean root canals were not found in either instrumentation group. In the coronal and middle thirds, the canal walls of both instrumentation groups were clean, with no or only small areas of debris and smear layer. In the apical region, there were higher scores in terms of debris and smear layer in both instrumentation groups. No significant difference was found at the inner wall of the 2 instrumentation groups in terms of debris mean score. However, the outer canal walls prepared with ProTaper showed lower debris score compared with those prepared with Hero Shaper (P Ͻ 0.001). Concerning the smear layer, both the inner and outer canal walls prepared with ProTaper showed lower mean scores compared with those prepared with Hero Shaper (P Ͻ 0.001). Conclusions. Within the limitations of this study, both instruments in combination with NaOCl and EDTA irrigation produced a clean and debris-free canal surface in the coronal and middle thirds, but were unable to produce a canal surface free from debris and smear layer in the apical third. However, the canals prepared with ProTaper instruments showed smaller amounts of debris and smear layer remaining in the apical region. (Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2008;106:e63-e71)

Nanoscale Research Letters, 2013

In this study, different nanofluids with phase change behavior were developed by mixing a molten ... more In this study, different nanofluids with phase change behavior were developed by mixing a molten salt base fluid (selected as phase change material) with nanoparticles using the direct-synthesis method. The thermal properties of the nanofluids obtained were investigated. These nanofluids can be used in concentrating solar plants with a reduction of storage material if an improvement in the specific heat is achieved. The base salt mixture was a NaNO 3-KNO 3 (60:40 ratio) binary salt. The nanoparticles used were silica (SiO 2), alumina (Al 2 O 3), titania (TiO 2), and a mix of silica-alumina (SiO 2-Al 2 O 3). Three weight fractions were evaluated: 0.5, 1.0, and 1.5 wt.%. Each nanofluid was prepared in water solution, sonicated, and evaporated. Measurements on thermophysical properties were performed by differential scanning calorimetry analysis and the dispersion of the nanoparticles was analyzed by scanning electron microscopy (SEM). The results obtained show that the addition of 1.0 wt.% of nanoparticles to the base salt increases the specific heat of 15% to 57% in the solid phase and of 1% to 22% in the liquid phase. In particular, this research shows that the addition of silica-alumina nanoparticles has a significant potential for enhancing the thermal storage characteristics of the NaNO 3-KNO 3 binary salt. These results deviated from the predictions of the theoretical model used. SEM suggests a greater interaction between these nanoparticles and the salt.

Journal of Dentistry, 2012

The aim of this study was to investigate the mechanical properties of five types of fibre-reinfor... more The aim of this study was to investigate the mechanical properties of five types of fibre-reinforced composite (FRC) posts and compare them with traditional metal post. Five FRC posts and a metallic post having different geometry and type of fibre (glass, carbon or quartz fibre) were loaded to failure in compression and bending. The transverse sections of FRC posts were observed using SEM to evaluate the fracture mode and the percentage of fibres (compared with burn-off test). Densities and voids content were also evaluated. Mechanical results were subjected to a one-way ANOVA and Tukey test (p&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;0.05). In compression, quartz fibre posts exhibited the greater maximum load and ultimate strength, carbon fibre posts showed a poor compressive behaviour. All posts had similar compressive moduli. Carbon posts showed the highest flexural properties (p&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;0.0001) while glass posts the greater maximum load. The fracture load values correlated to the diameters of posts showed a parabolic behaviour. The flexural strengths of all posts were four and seven times higher than dentine. The elastic moduli of almost all posts were similar to dentine. The compressive strengths were lower than flexural strengths. The fibre diameters ranged from 5.2 to 26 μm, the volume percentage of fibres was about 64%. The content of voids of some posts lower their mechanical behaviour. Compressive properties of FRC posts were lower than in bending. The flexural properties of FRC posts were higher than the metal post and similar to dentine. The mechanical behaviour is influenced by voids.

Journal of heat transfer, Jan 10, 2018

Composites Part A: Applied Science and Manufacturing, 2013

Solar Energy, 2018

Materials science & engineering. C, Materials for biological applications, 2019

Journal of Heat Transfer, 2018

Solar Energy Materials and Solar Cells, 2017

Materials Science and Engineering: C, 2017

Nanomaterials, 2016

Microscopy and Microanalysis, 2015

Nanoscale research letters, 2015

Oral Surgery, Oral Medicine, Oral Pathology, Oral Radiology, and Endodontology, 2008

Nanoscale Research Letters, 2013

Journal of Dentistry, 2012

The overall objective of heat storage integration is to increase the solar contribution, to impro... more The overall objective of heat storage integration is to increase the solar contribution, to improve efficiency and to reduce the LEC. The latent heat thermal energy storage (LHTES) systems, using phase change materials (PCMs), have been gaining importance in the last years for their high energy storage density and their ability to charge and discharge a large amount of heat at a constant temperature during phase transition. The PCMs used as storage media (for medium-high temperature solar applications as concentrated solar thermal power, CSP) are in general molten salts. Nowadays the research is focusing on the development of new storage materials able to provide a higher energy stored density, specific heat and latent heat that can lead to a reduction of the overall thermal storage media volume, energy losses and total costs. Nanofluids (obtained dispersing nanoparticles in heat transfer fluids) have been considered for applications as advanced heat transfer fluids, since they have better suspension stability compared to micron-sized solid particles and provide enhanced thermal properties. Lately, research is focusing on the development of nanofluids obtained with the addition of nanoparticles to nitrate salts and the evaluation of the specific heat. In the past five years we studied different oxide nanoparticles and preparation methodologies (in water solution and a direct high temperature mixing). The future work will focus on the development of carbon based nanofluids. They are in fact potentially good candidate in the increase of thermal properties (as our first results indicate) since they are very good thermal conductors.

The aim of this work was to analyse the durability of sandwich panels with a honeycomb aluminium ... more The aim of this work was to analyse the durability of sandwich panels with a honeycomb aluminium core and composites skins based on epoxy resin and carbon-glass fibres. Ageing tests have been developed and the mechanical properties after ageing were evaluated. In particular the specimens were edge-sealed on all sides to prevent the water ingress in the core and submitted to this cycle: in water at 50°C for 1h, heating in dry air at 70°C for 3h, spraying with hot water at 70°C for 3h, heating in dry air at 70°C for 18h. They were then subjected to compression (edgewise and flatwise) and bending. Moreover, the sandwiches were subjected hot-wet conditions (at 70°C in distilled water for 3 and 5 weeks) and tested to flatwise tension test: the bond between core and skins was evaluated. Undamaged specimens simulated the ingress of water by diffusion and specimens with perforated surface simulated the direct ingress of water due to defects.
This work showed a decrease of bending properties of 20% for specimens with fibres oriented at 90°and of about 50% for those at 0°. A reduction of the compression moduli due to ageing was found: 43-51% for the edgewise and 59% for flatwise. Moreover, the flatwise tension tests under hot-wet conditions (70°C-100% urs) showed a decrease of the Young’s modulus (63% after 5 weeks), while the tensile strength was halved.

This work reports the development of a phase change material using different nanoparticles embedd... more This work reports the development of a phase change material using different nanoparticles embedded in a molten salt and the thermal characterization of the nanofluid obtained. This can be used in a concentrating solar power plants with a reduction of storage material if an improvement in the specific heat is achieved. Different kind of nanoparticles were dispersed in potassium and sodium nitrates (60:40 ratio) to obtain high temperature nanoﬂuids. The nanoparticles added were: silica, alumina, titania and a mixture of alumina and silica. They were dispersed in water solution along with the molten salt as follows: 198 mg of molten salt and 2 mg of nanoparticles were dispersed in 20 ml of distilled water using an ultrasonic bath for 100 min. The water solution was then evaporated at 200°C . The molten salt (PCM) and the nanofluids obtained were then subjected to calorimetric analysis (5 min at 150°C followed by 150°C-300°C at 20°C/min, 5 min at 300°C and 300°C-150°C at 20°C/min).
The effect of different percentage was also evaluated (from 0.5% to 1.5%).The dispersion of the nanoparticles was analysed by SEM after calorimetric test.
The effect of the nanoparticles on the phase change material analysed was evaluated from DSC measurements. In particular the speciﬁc heat (Cp) was the main thermal property analysed but also the heat of fusion, the melting point, and the onset temperatures were calculated for each nanofluid.
Calorimetric analysis show that the addition of nanoparticles to base salt increases the Cp up to 58% in solid phase and up to 22% in liquid phase. The higher increase of Cp was obtained with the addition of silica-alumina nanoparticles. SEM micrographs suggest a greater interaction between silica-alumina nanoparticles and the base salt.

The aim of this work was the development of a phase change material using different nanoparticles... more The aim of this work was the development of a phase change material using different nanoparticles embedded in a molten salt base material and the thermal characterization of the nanofluid obtained. This can be used in a concentrating solar power plants with a reduction of storage material if an improvement in the specific heat is achieved. Different kind of nanoparticles (1%wt) were dispersed in potassium and sodium nitrates (60:40 ratio) to obtain high temperature nanoﬂuids. The nanoparticles added were: silica, alumina, a mixture of alumina and silica (14%-86%) supplied by Evonik and titania supplied by Sachtleben. Each nanofluid was prepared as follows: 198 mg of molten salt and 2 mg of nanoparticles were dispersed in 20 ml of distilled water using an ultrasonic bath for 100 min (same procedure for the base salt). The water solution was then evaporated on a hot plate at 200°C. The neat molten salt and the nanofluids obtained were then analyzed by DSC with the following method: 5 min at 150°C followed by 150°C-300°C at 20°C/min, 5 min at 300°C and 300°C - 150°C at 20°C/min (cycle repeated 6 times). The main thermal property analyzed was the speciﬁc heat (Cp). DSC results show that the addition of nanoparticles to base salt increases the Cp of 15-57% in solid phase and up to 22% in liquid phase. The higher increase of Cp was obtained with the addition of silica-alumina nanoparticles. The dispersion of the nanoparticles was analyzed by SEM microscope after DSC test. SEM micrographs suggest a greater interaction between silica-alumina nanoparticles and the base salt. This work showed that an increase in specific heat is achievable with the use of nanoparticles which is useful for storage systems.

In this work the effective mechanical properties of nanocomposites with oriented carbon nanotubes... more In this work the effective mechanical properties of nanocomposites with oriented carbon nanotubes (CNTs) in different polymers were evaluated by means of finite element method (FEM) and a representative volume element (RVE). The model is useful to provide expected properties of nanocomposite before any experimental test. It was observed that little increment in longitudinal shear moduli G xz and in transversal modulus (Ex=Ey) can be obtained by adding CNTs. The effect is predominant in the effective longitudinal modulus E z and it is higher with a greater nanotube weight fraction.

Carbon nanotubes (CNTs) may increase the mechanical properties of many different polymers. In thi... more Carbon nanotubes (CNTs) may increase the mechanical properties of many different polymers. In this work the effective mechanical properties of CNT-based nanocomposites randomly distributed are evaluated by means of finite element method (FEM) and a representative volume element (RVE). A particular algorithm was created to introduce random CNTs inside a polymeric matrix and different loads in x,y, z directions were applied. The model is useful to provide expected properties of nanocomposite before any experimental test.

Book: Intelligent Nanomaterials, 2nd Edition, Nov 2016

This chapter describes recent progress on the development of suspensions of nanometer-sized solid... more This chapter describes recent progress on the development of suspensions of nanometer-sized solid particles in base liquids [nanofluids (NFs)] for thermal energy storage (TES) application. Among the various methods of energy storage, latent heat TES systems using phase change materials (PCMs) have been gaining importance in many fields due to their high energy storage density and their ability to provide heat at a constant temperature with an overall reduction of costs. The chapter starts with a description of TES and continues with some useful definitions of the NFs and their material components (base fluid and nanoparticles). A brief presentation of different types of NFs is reported along with the principal methods of NF preparation. NFs based on salts as PCMs with the addition of different nanoparticles are considered. This chapter focuses on the heat capacity enhancement of NFs with a comparison of both theoretical models and experimental results since it can lead to a reduction in the amount of storage material. Other fundamental thermal properties are reported in the chapter (heat of fusion, melting temperatures, and thermal storage capability and thermal conductivity). Finally, the challenges of using NFs in solar energy devices are discussed.