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The purpose of this paper is to study the manufacturing of SAC 305 solder paste with multiwall carbon nanotubes (MWCNT) before and after structure modification and also to investigate the added carbon nanotubes' influence on the technological properties and the microstructure of “nano” solder pastes. This work is a continuation of similar previous studies of SAC solder pastes with silver nanopowder additions.

The authors applied functionalization and esterification methods for the structural modification of the carbon nanotubes. The “nano” solder paste preparation was performed with the use of a two‐stage method of carbon nanotube dispersion in “own‐manufactured” SAC 305 solder paste. To determine the technological properties of the “nano” solder paste, slump, solder ball, wetting and spreading tests were applied according to the existing standards. Standard metallographic procedures were applied for microstructural analysis.

As expected on the basis of the previous studies of SAC solder pastes with silver nanopowders, positive results were obtained for the own‐manufactured SAC 305 solder paste with carbon nanotubes by applying the dispersion method. Also applied were functionalization and esterification methods, whose results showed microstructural changes in the carbon nanotubes. The “nano” SAC solder pastes showed a positive influence on the slump properties, compared to the basic SAC solder paste. The authors proved a negative influence of the carbon nanotubes' addition (dependent on their concentration) on the spreading and wetting of the SAC solder paste on a copper substrate, which provoked the non‐wetting and dewetting phenomena. A slight improvement was observed for the “nano” SAC solder pastes with modified carbon nanotubes. The carbon nanotubes' presence in the solder paste showed a positive effect on the growth reduction of the IMCs' thickness, which depended on the type.

The authors intend to verify the reinforcement effect of the alloys with carbon nanotubes suggested in the literature (the aim of Part II). For this purpose, an assembly process with RC electronic elements on PCBs with Ni/Au and SAC (HASL) finishes will be performed, with the use of the SAC 305 solder paste with modified carbon nanotubes, for the purpose of reflow soldering. Next, measurements of the mechanical strength of the solder joints and their microstructures will be conducted.

It is suggested that further studies of the mechanical properties and the reliability of solder joints are necessary for the practical implementation of the “nano” SAC solder pastes, but taking into account the wetting data, the investigation should be performed only for “nano” pastes with the lowest additions of modified carbon nanotubes.

The paper demonstrates a method of “nano” solder paste preparation by means of a two‐stage dispersion of carbon nanotubes in the own‐manufactured SAC 305 solder paste and a comparison study of the properties of “nano” pastes with the basic SAC solder paste.

Wearable electronics is an emerging technology predicted to become a 50B$ industry by 2018. Components and circuits will be highly integrated into clothing and other apparel. One crucial factor is the need for highly robust, flexible printed circuit tracks with sufficiently high electrical conductivity. The fact that metal-based tracks tend to suffer from fatigue failure has driven the development of alternative materials. The paper aims to discuss these issues.

Alternative materials are organic conductors and carbon nanotubes. The latter has a great flexibility and intrinsic strength. While nanotubes can be solubilised and printed using ink-jet techniques, this usually requires polymer additives. The paper has therefore sought to develop a novel solvent-free dry-ink.

The paper has found that it is possible to directly transfer from a nanotube growth substrate, via a hard print stamp head, onto a flexible rubber substrate and that one loading of the stamp can give many individual prints before exhaustion: the dry-ink stamp face effectively de-layers by a set amount each time a print is made. Many consecutive, highly consistent and uniform prints can be made using this approach. When printed onto natural rubber, the printed tracks are very robust and can be stretched to 100 per cent strain without permanent damage. The electrical conductivity can be improved by a simple alcohol treatment to consolidate the fibers and by iodine doping reaching 38 S · cm−1.

The findings offer an economical way to print highly robust electrically conductive tracks of carbon nanotubes directly onto flexible substrates.

The purpose of this work is to investigate the influence of carbon nanotube additions to solder paste on the solder joints mechanical strength and their microstructure. In our investigation, the basic solder paste contains 85 wt.% of the commercial Sn96.5Ag3Cu0.5 powder (with the particle sizes in the range of 20‐38 μm) and 15 wt.% of the self‐prepared middle activated rosin flux. To this paste we added the 0.01, 0.05 and 0.1 wt.% of the self‐modified CNT by functionalized them by mineral acid and than esterificated by methanol (FCNT_Met) or polyethylene glycol 400 (FCNT_PG). After the pastes had stabilized, the reflow soldering process of “zero ohm” chip resistors on PCBs with Ni/Au and SAC (HASL) finishes was carried out and then shear strength of the solder joints was measured. The correlations between the mechanical strength of solder joins without and with the carbon nanotubes and their microstructure were analysed.

For shear strength measurement of solder joints, the printed circuit boards with Ni/Au and SAC (HASL) finishes was applied. The SAC solder paste with different carbon nanotubes and the basic SAC solder paste as reference were used for this experiment. The automatic SMT line was applied for the paste screen printing; “zero ohms” chip resistors: 0201, 0402, 0603 and 0805 were placing on PWBs and then reflowing according to appropriate time – temperature profile. The shear strength of the solder joints was measured. For the solder joints microstructure analysis, the standard metallographic procedures were applied. Changes in the microstructure, the thickness of the intermetallic compounds and their chemical compositions were observed by means of the SEM equipped with EDS.

As the authors expected, the SAC solder paste with the carbon nanotubes addition improve the solder joints shear strength of the chip resistors mounted on PCBs with Ni/Au and SAC (HASL) finishes. The carbon nanotubes addition positive effects on IMCs thickness because of blocking their excessive growth.

It is suggested that further studies are necessary for the confirmation of the practical application, especially of the reliability properties of the solder joints obtained using solder paste with chosen carbon nanotubes.

Taking into account the shear strength data, the best results of the “nano” SAC solder pastes were obtained for the lowest addition of the carbon nanotubes modified by esterification process, especially by the methanol compared to the polyethylene glycol 400.

The obtained results made it possible to draw conclusions regarding the correlation between the output of the mechanical results and the amount of the added carbon nanotubes, and also the microstructure and thickness of the IMCs of the “nano” solder joints. It can be useful from practical point of view.

The purpose of this paper is to focus on the influence of electromagnetic field during the arc discharge carbon nanotubes synthesis. It proposes modeling of electromagnetic field distribution to calculate forces in the area of arcing. The paper presents the influence of this field on the final product of the synthesis.

A short literature review of the arc discharge systems supported by electromagnetic field is presented. The technical solution of the coil placement is discussed. An experimental research is described. The research system constructed preceded by a series of measurements and modeling is analyzed.

The paper describes the significant meaning of the electromagnetic field during the synthesis. The electromagnetic field forces the slow rotation of the carbon plasma column where carbon nanotubes are formed. It leads to the improvement in yield.

Because the research is limited to one type of geometry of the reactor, the results may vary in different reactors. However, the influence of the electromagnetic field is confirmed. Therefore, researchers are encouraged to investigate the influence of the electromagnetic coil in the applied systems.

The systems with a coil inside the reactor require the application of complex cooling systems or/and additional screens. The work proposes a technical solution based on the coil placed outside the reactor. Therefore, it simplifies the construction and increases the yield.

The high yield of the high-quality nanotubes opens new technical possibilities for electronics and electrical engineering.

The paper identifies a connection between the electromagnetic field, the arc discharge movement, plasma jet, carbon nanotubes containing deposit and the yield.

The synergistic effect of functionalization of multi-walled carbon nanotubes (CNT) using KMnO4 oxidation and initial tensile deformation on the electrical resistance of nanotube network/polyurethane composite subjected to elongation was studied.

Though the initial deformation irreversibly changed the arrangement of carbon nanotube network, subsequent cyclic elongation confirmed stable resistance values. The increased strain-dependent resistance of stimulated nanotube network/polyurethane composite was demonstrated by monitoring vibration of tambour leather after a bead impact and finger flexion.

The results showed a tenfold composite resistance increase for the composite prepared from KMnO₄ oxidized nanotubes, quantified by a so-called gauge factor, from a value of about 20 in comparison to the network prepared from pristine nanotubes. This is a substantial increase, which ranks the stimulated composite among materials with the highest electromechanical response.

The results in this paper are new and have not been published yet. The paper combines different ideas which are developed together. It presents a new concept of synergistic effect of CNT oxidation and application of pre-strain simulation. Oxidation and pre-strain increases by several times the sensitivity of the tested composites which are predetermined for use as strain sensors of various sizes and shapes.

This paper aims to modify carbon nanotubes with oleic acid, and to study the tribological properties of castor oil with modified carbon nanotubes additives. The proper additives are sought for the future engineering application of castor oil.

Tribological properties of the castor oils mixed with the modified carbon nanotubes of four mass percentages were investigated using a four-ball testing rig. Coefficient of friction and wear scar diameter were obtained in each test, and the mechanism of modified carbon nanotubes and castor oil was discussed.

The results indicated that modified carbon nanotubes had better dispersion in castor oil. Coefficient of friction first increased, then decreased and finally grew stable with the time, and wear scar diameter of steel surface functioned as a first reduced then increased change with the additive mass percentage of modified carbon nanotubes. The minimum of average coefficient of friction and wear scar diameter occurred at 0.02 Wt.% modified carbon nanotubes.

A small amount of modified carbon nanotubes could improve properties of the castor oil, and the mixed castor oil with 0.02 Wt.% modified carbon nanotubes would be most possibly used in engineering applications.

Nowadays, nano-antennas or nanoscale absorbers made by innovative materials such as carbon nanotubes are gaining more and more interest, because of their outstanding features. The purpose of this paper is to investigate the scattering properties of carbon nanotubes, either isolated or arranged in arrays. The peculiar behaviour of such innovative materials is studied, taking also into account the finite length of the structure and the dependence of the scattering field from the operating temperature.

First a model is presented for the electrical transport along the carbon nanotubes, based on Boltzmann quasi-classical transport theory. The model includes quantistic and inertial phenomena observed in the carbon nanotube electrodynamics. The model also includes the effects of temperature. Using this electrodynamical model, the electromagnetic formulation of the scattering problem is cast in terms of a Pocklington-like equation. The numerical solution is obtained by means of the Galerkin method, with special care in handling the logarithmic singularity of the kernel. Case studies are carried out, either referred to isolated single-wall carbon nanotubes (SWCNTs) and array of SWCNTs.

The scattering properties of SWCNT are strongly influenced by the temperature and by the distance between the tubes. As temperature increases, the amplitude of the resonance peaks decreases, at a rate which is double the rate of changes of temperature. The resonance frequencies are insensitive to temperature. As for the distance between the tubes in an array, it influence the scattering resonance introducing a shift in the resonance frequencies which is appreciable for distances lower than the semi-length of the CNT. For higher distances the CNT scattered field may be regarded as the sum of the fields emitted by each CNT, as if they were isolated.

As far as now only SWCNTs have been studied. The multi-wall carbon nanotubes would show a richer behaviour with temperature, due to the joint effect of reduction of the mean free path and increase of the number of conducting channels, as temperature increases.

Possible use of carbon nanotubes as absorbing material or scatterers.

The model presented here is based on a self-consistent and physically meaningful description of the CNT electrodynamics, which takes rigorously into account the effect of temperature, size and chirality of each CNT.

A computational structural mechanics approach, based on the exclusive use of standard bar elements is utilized in order to investigate the elastic stability of single-walled carbon nanotubes (SWCNTs) with atom vacancy defects under axial compressive loads. The paper aims to discuss this issue.

The proposed model uses three dimensional, two nodded, linear truss finite elements of three degrees of freedom per node to represent the force field appearing between carbon atoms due to the basic interatomic interactions.

Numerical results concerning the critical forces which cause instability of pristine nanotubes are compared with corresponding data given in the open literature in the effort to demonstrate the good accuracy of the method. Then, it is assumed that SWCNTs present-specific structural defects defined by their length, width, orientation and longitudinal position. The influence of these four geometric parameters of the imperfections considered on the stability of SWCNTs is investigated in detail and essential conclusions are revealed.

To the authors’ best knowledge, is the first time that the specific method is introduced for the prediction of buckling behavior of defective SWCNTs. The structural defect here is considered as atoms vacancy that forms a like-crack defect having a specific length, width, orientation and position along the nanotube length.

This paper aims to investigate effects of acrylic functionalisation of multiwalled carbon nanotubes (MWCNTs) on properties of carbon nanotubes/epoxy nanocomposites.

A number of analytical techniques, including Fourier transform infrared spectroscopy, Raman spectroscopy, scanning electron microscopy and transmission electron microscopy, were used to assess the effects of acid treatment on MWCNTs. Ultraviolet-curable coatings were fabricated by sonication and cast moulding process. The mechanical properties of MWCNTs/epoxy composites at different weight fractions were evaluated by performing tensile tests and dynamic mechanical analysis tests. Also, gel contents were examined.

It was found that addition of nanotubes monomer to epoxy formulations had significant effect on the viscoelastic and mechanical properties.

Improving dispersion and alignment of MWCNTs in the composite matrix will contribute to the development of resin/MWCNTs nanocomposites and promote the applications.

The paper establishes a method to introduce MWCNTs into epoxy matrix as a monomer to enhance the photo curable and dispersion properties of the MWCNT/epoxy films.

The purpose of this paper is concerned with the study of nonlinear ultrasonic waves in a magneto-flexo-thermo (MFT) elastic armchair single-walled carbon nanotube (ASWCNT) resting on polymer matrix.

A mathematical model is developed for the analytical study of nonlinear ultrasonic waves in a MFT elastic armchair single walled carbon nanotube rested on polymer matrix using Euler beam theory. The analytical formulation is developed based on Eringen’s nonlocal elasticity theory to account small scale effect. After developing the formal solution of the mathematical model consisting of partial differential equations, the frequency equations have been analysed numerically by using the nonlinear foundations supported by Winkler-Pasternak model. The solution is obtained by ultrasonic wave dispersion relations.

From the literature survey, it is evident that the analytical formulation of nonlinear ultrasonic waves in an MFT elastic ASWCNT embedded on polymer matrix is not discussed by any researchers. So, in this paper the analytical solutions of nonlinear ultrasonic waves in an MFT elastic ASWCNT embedded on polymer matrix are studied. Parametric studies is carried out to scrutinize the influence of the nonlocal scaling, magneto-electro-mechanical loadings, foundation parameters, various boundary condition and length on the dimensionless frequency of nanotube. It is noticed that the boundary conditions, nonlocal parameter and tube geometrical parameters have significant effects on dimensionless frequency of nanotubes.

This paper contributes the analytical model to find the solution of nonlinear ultrasonic waves in an MFT elastic ASWCNT embedded on polymer matrix. It is observed that the increase in the foundation constants raises the stiffness of the medium and the structure is able to attain higher frequency once the edge condition is C-C followed by S-S. Further, it is noticed that the natural frequency is arrived below 1% in both local and nonlocal boundary conditions in the presence of temperature coefficients. Also, it is found that the density and Poisson ratio variation affects the natural frequency with below 2%. The results presented in this study can provide mechanism for the study and design of the nano devices such as component of nano oscillators, micro wave absorbing, nano-electron technology and nano-electro--magneto-mechanical systems that make use of the wave propagation properties of ASWCNTs embedded on polymer matrix.