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1

Simulation and Heat Treatment Process of Carbon Nanotube Modified Aluminum Alloy (ZL105)

Zhang Zigi, Pan Zhilin, Li Rong, Zeng Qi, Liu Yong, Wu Quan

Archives of Foundry Engineering

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2023

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Vol. 23, iss. 3

38--50

EN

To further improve the mechanical properties of carbon nanotubes (CNTs) modified aluminum alloy (ZL105), the first principle was used to build the atomic structure of the alloy system and the alloy system was simulated by the VASP. After that, the heat treatment process of the cast aluminium alloy material with CNTs to enhance the alloy performance by the orthogonal experiment. The results of the research show that: (1) The energy status of the alloy system could be changed by adding the C atoms, but it did not affect the formation and structural stability of the alloy system, and the strong bond compounds formed by C atoms with other elements inside the solid solution structure can significantly affect the material properties. (2) The time of solid solution has the greatest influence on the performance of material that was modified by CNTs. The solution temperature and aging temperature were lower strength affection, and the aging time is the lowest affection. This paper provides a new research method of combining the atomic simulation with the casting experiment, which can provide the theoretical calculations to reduce the experiment times for the casting materials’ performance improvement.

2

Influence of Carbon Particle in Polymer Matrix Composite over Mechanical Properties and Tribology Behavior

Sravanthi K., Mahesh V., Nageswara Rao Boggarapu

Archives of Metallurgy and Materials

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2021

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Vol. 66, iss. 4

1171--1178

EN

In this research, the carbon particle dispersions are made in two different levels as carbon nano tube (CNT) and carbon particle in microns range. The mechanical strength is evaluated for the composites developed by axial loading and bending test analysis. In addition, the air jet abrasive particle erosion study is performed for different angle of impingement. The dispersion of carbon particle in the matrix material has reduced the mechanical strength. The sample with 4% of CNT dispersion in the composite has a maximum strength of 143 MPa and a minimum strength of 112 MPa. For the same combination (4% of CNT composite), the maximum flexural strength is 116 MPa. It is clear to infer that the strength of CNT in matrix materials is superior to the increase in length of carbon particle. The dispersion of carbon particle in the matrix material increases the brittleness and the strength is diminished. During the flexural bending, the fiber delamination occurred with severe deformation in the plain composite. When the materials are subjected to impingement of solid particle, the attrition effect on the exposed surfaces is vulnerable towards erosive mechanism. The presence of carbon in the matrix material has significantly increased the surface property. The results are appreciable for 4% of CNT composite. Especially at 30º, the minimum erosive wear 0.0033 g/g has been recorded. Erosive wear is less at minimum impingement angle and the wear is found increasing at higher impingement angle. Therefore, it is recommended not to add carbon particle to a higher weight percentage, since it leads to brittleness.

3

New generation of semipermeable membranes with carbon nanotubes for water and wastewater treatment : Critical review

Bodzek Michał, Konieczny Krystyna, Kwiecińska-Mydlak Anna

Archives of Environmental Protection

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2021

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Vol. 47, no. 3

3-27

EN

Environmental applications of carbon nanotubes (CNTs) have recently attracted worldwide attention due to their excellent adsorption capacities and promising physical, chemical and mechanical properties, as well as the preparation of novel membranes with attractive features for water purification. This paper critically reviews the recent progress on the preparation and applications of CNT based membranes in water and wastewater treatment. Various synthesis techniques for the preparation of CNT based membranes are discussed. The functionalization of CNTs, which involves chemical/physical modification of pristine CNTs with different types of functional groups, improves the capabilities of CNT for water and wastewater treatment and/or removal of waterborne contaminants. The CNT-based membrane applications are found to possess a variety of advantages, including improving water permeability, high selectivity and antifouling capability. However, their applications at full scale are still limited by their high cost. Finally, we highlight that CNT membranes with promising removal efficiencies for respective contaminants can be considered for commercialization and to achieve holistic performance for the purpose of water treatment and desalination. This paper may provide an insight for the development of CNT based membranes for water purification in the future. With their tremendous separation performance, low biofouling potential and ultra-high water flux, CNT membranes have the potential to be a leading technology in water treatment, especially desalination.

4

Wybrane metody utleniania wielościennych nanorurek węglowych

Bielicka Agnieszka, Hajok Sonia, Nowak Mariusz, Wiśniewski Marek

Przemysł Chemiczny

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2020

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T. 99, nr 6

897--900

PL

Przedstawiono dwie metody utleniania wielościennych nanorurek węglowych (CNT), przy użyciu stężonego kwasu azotowego(V) oraz mieszaniny stężonych kwasów azotowego(V) i siarkowego(VI). Dodatkowo zbadano wpływ działania ultradźwięków na ilość utworzonych grup funkcyjnych. Do oceny modyfikacji powierzchni CNT zastosowano metodę termograwimetryczną, spektroskopię Ramana, metodę Boehma oraz pomiar potencjału zeta i ciepła immersji w wodzie. Duże stężenie tlenowych grup funkcyjnych (2,23 mmol/g) uzyskano, stosując mieszaninę stężonych kwasów i ultradźwięki przez 6 h. Tak długi czas procesu przyczynił się jednak do znacznego zniszczenia struktury węglowej.

EN

The multiwall C nanotubes (CNT) were oxidized with concd. HNO₃ or its mixt. with H₂SO₄ optionally under ultrasonication. Thermogravimetric anal., Raman spectroscopy and Boehm method, as well as detn. of heat of immersion in H₂O and zeta potential were used to characterize the CNT surface modification. The large amt. of acidic functional groups (2.23 mmol/g) was obtained when a mixt. of acids and ultrasonication for 6 h were used. The longtime contributed however to a significant decompn. of the C structure.

5

Wpływ właściwości nanorurek węglowych na ich nanotoksyczność

Szymańska Alicja, Michalkiewicz Beata

Przemysł Chemiczny

|

2019

|

T. 98, nr 8

1341--1343

PL

Nanomateriały mają bardzo szerokie możliwości aplikacyjne, jednak ich stosowanie może powodować niezbadane dotąd zagrożenie dla środowiska i człowieka. Jednymi z najbardziej znanych nanomateriałów, które znalazły wiele zastosowań ze względu na unikatowe właściwości są nanorurki węglowe. Mimo że nanorurki węglowe są zwykle zbudowane tylko z jednego pierwiastka, który jest uważany za bezpieczny (węgiel) to wykazują odmienne właściwości fizykochemiczne. Pozwala to przypuszczać, że mogą wykazywać różną toksyczność. Przedstawiono przegląd badań naukowych w zakresie wpływu właściwości nanorurek węglowych na ich nanotoksyczność.

EN

A review, with 31 refs., of toxic properties of C nanotubes and their impact on living organisms. The effect of their length and diam., their aggregation in the living organisms, the presence of impurities and surface properties were taken into consideration.

6

CNTFET Based OTRA and its Application as Inverse Low Pass Filter

Prasad Dinesh, Tayal Divyam, Yadav Ayesha, Singla Laxya, Haseeb Zainab

International Journal of Electronics and Telecommunications

|

2019

|

Vol. 65, No. 4

665--670

EN

Operational Transresistance Amplifier (OTRA) has been a topic of great interest recently. OTRA has proved itself to be an appropriate device for the analog applications. As MOS scaling suffers from various problems, carbon nanotube field effect transistor (CNTFET) has came into light as one of the brightest alternative for FET (Field Effect Transistors) based devices. This work has introduced a new CNTFET based OTRA which is capable of realising inverse low pass filter using two OTRAs and few passive elements. CNTFET based OTRA has been designed and simulated at 10nm technology node. The working ability of the designed model has been conformed using HSPICE simulation. It is compared with conventional CMOS based OTRA. The comparative analysis has revealed improvement in various performance parameters. The paper also presents how change in number of carbon nanotube in CNTFETs in OTRA circuit affects the transresistance gain and input impedance. The optimized results are also discussed to improve transresistance gain and input impedance. The paper also dealt with the realisation of inverse low pass filter using proposed CNTFET based OTRA.

7

Microstructure and Mechanical Properties of Al-3 Vol% CNT Nanocomposites Processed by High-Pressure Torsion

Asgharzadeh H., Kim H. S.

Archives of Metallurgy and Materials

|

2017

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Vol. 62, iss. 2B

1109--1112

EN

Al-3 vol% CNT nanocomposites were processed by high-pressure torsion (HPT) at room temperature under the pressure in the range of 2.5-10 GPa for up to 10 turns. Optical microscopy, scanning electron microscopy, and transmission electron microscopy (TEM) were used to investigate the microstructural evolutions upon HPT. Mechanical properties of the HPT-processed disks were studied using tensile tests and microhardness measurements. The results show gradual evolutions in the density, microstructure, and hardness with increasing the number of turns and applied presure. Nanostructured and elongated Al grains with an average grain thickness of ~40 nm perpendicular to the compression axis of HPT and an aspect ratio of ~3 are formed after 10 turns under 6 GPa. Evaluating the mechanical properties of the 10-turn processed Al/CNT nanocomposites indicates a tensile strength of 321 MPa and a hardness of 122 Hv. The tensile fracture surface of the Al/CNT nanocomposite mostly demonstrates a smooth fracture manner with fine dimples resulting in a low tensile ductility of ~1.5%.

8

Fabrication of AZ31/CNT Surface Nano-composite by Double-pass Friction Stir Processing

Kim J. Y., Hwang J.-W., Kim H. Y., Lee S. M., Jung W.-S., Byeon J.-W.

Archives of Metallurgy and Materials

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2017

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Vol. 62, iss. 2B

1039--1042

EN

Double-pass Friction Stir Processing (FSP) was applied to fabricate an AZ31/CNT nano-composite for surface hardening of lightweight structural components. The effects of double-pass FSP as well as groove depth (i.e., volume fraction of CNT) on the CNT distribution, dynamically recrystallized grain size, and resulting microhardness were studied. Double-pass FSP was performed for the CNT-filled plate-type specimen with different groove depths of 2, 3, and 4 mm. By applying double-pass FSP, the average size of CNT clusters decreased, implying a more homogeneous distribution. Compared with the FSPed specimen without CNT, grain size was refined from 19 μm to 3 μm and microhardness increased from 52 Hv to 83 Hv (i.e., 71% increase).

9

Elastic analysis of polymeric cylinders reinforced with carbon nanotubes

Hosseini H., Kolahchi R., Heydari M.

Journal of Applied Mathematics and Computational Mechanics

|

2016

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Vol. 15, nr 2

31--39

EN

In this work, stress analysis of a polymeric cylinder’s cylindrical shell reinforced with carbon nanotubes (CNTs) is investigated. The cylinder is subjected to mechanical and thermal loadings. All the equivalent mechanical and thermal properties of nano-composite cylinder are obtained using Mori-Tanaka model. Based on equilibrium, the governing equation is derived. Using an exact solution, the stresses and radial displacement distributions in the structure are calculated. The effects of CNTs volume percent on the stresses and radial displacement for internal and external pressure cylinder are the main discussion of this study. Numerical results indicate that with increasing CNTs volume percent, the stresses decrease. However, this shows the important effect of nanotechnology in stress reduction of cylinder which may be useful in sensors and actuators.

10

Badania wpływu różnych odmian alotropowych węgla w kompozytach Al-C na ich odkształcalność w procesie ciągnienia

Knych T., Mamala A., Kwaśniewski P., Kiesiewicz G., Kawecki A., Smyrak B., Gniełczyk M., Korzeń K.

Hutnik, Wiadomości Hutnicze

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2015

|

Vol. 82, nr 1

64--67

PL

Współczesne oczekiwania elektroenergetyki koncentrują się na materiałach przewodzących o przewodności elektrycznej wyższej od przewodności materiałów bazowych tj. miedzi i aluminium. Odkrycie naukowe ostatnich lat − grafen − jedna z najbardziej szlachetnych alotropowych odmian węgla o bardzo wysokiej przewodności elektrycznej i cieplnej oraz wytrzymałości mechanicznej − stwarza ogromne możliwości projektowania i wytwarzania nowych materiałów o ponadstandardowych własnościach eksploatacyjnych. W artykule przedstawiono wyniki badań i analizy wpływu różnych odmian alotropowych węgla w kompozytach Al-C na ich odkształcalność w procesie ciągnienia. W szczególności, badaniom własności elektrycznych i mechanicznych poddano kompozyty Al-C wytworzone przy wykorzystaniu syntezy metalurgicznej oraz syntezy różnych rodzajów proszków Al i C, a następnie wytworzone z nich druty.

EN

This article focuses attention on the possibilities of graphene and aluminum synthesis. The researches were made over the different methods of producing these materials, in particular: chemical synthesis consisting in the combination of liquid metal with graphene and mechanical synthesis of Al powders coated with graphene into a form suitable for further processing in the processes of plastic working into wires.

11

Geometry of the improved layer over a piston skirt

Iskra A., Krzymień P., Wróblewski E.

Combustion Engines

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2015

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R. 54, nr 3

192--196

EN

Geometry of the slot between piston skirt and cylinder bore affects the friction losses of the IC engine to the far extent. It appears that these losses depend more on the area covered with oil than the thickness of oil layer separating collaborating parts. Barrel-shaped or stepwise piston skirt is the way to reduce the oil covered area. The first concept has been used for years while the stepwise profile has not been applied for various reasons, although this idea providing higher load capacity of oil layer in stepwise slot was published in literature in the fifties of twentieth century. The stepwise profile can be obtained covering the cylindrical or taper piston skirt with a thin layer of carbon nanotubes (CNT). This paper presents the results of simulation and test stand investigations leading to the reduction in friction losses and abrasive wear of piston skirt and cylinder bore. Covering the piston skirt with a thin layer of CNT one can get an extremely advantageous tribological properties of the piston assembly which means the expected parameters of oil film and in a case of film rupture – an ignorable abrasive wear of the CNT layer and/or cylinder bore.

PL

Geometria szczeliny między powierzchnią boczną tłoka a cylindrem w bardzo dużym stopniu wpływa na straty tarcia w silniku spalinowym. Okazuje się, że na wymienione straty w większym stopniu wpływa obszar pokryty filmem olejowym niż grubość filmu olejowego rozdzielającego współpracujące elementy. Drogą do zmniejszenia obszaru pokrytego filmem olejowym jest baryłkowy lub schodkowy kształt powierzchni bocznej tłoka. Pierwszy sposób stosowany jest od dawna, natomiast kształt schodkowy z różnych powodów nie był dotychczas stosowany, chociaż publikacje o największej nośności filmu olejowego utworzonego w szczelinie schodkowej ukazały się jeszcze w latach pięćdziesiątych dwudziestego wieku. Kształt schodkowy szczeliny można uzyskać nanosząc cienką warstwę nanorurek węglowych (CNT) na cylindryczną lub stożkową powierzchnię boczną tłoka. W artykule przedstawiono wyniki badań stanowiskowych i symulacyjnych zmierzających do redukcji strat tarcia i zużycia ściernego powierzchni bocznej tłoka i gładzi cylindra. Syntetyzując na powierzchni bocznej tłoka cienką warstwę CNT uzyskuje się bardzo dobre właściwości trybologiczne pary kinematycznej, jaką stanowi zespół tłok – cylinder, co oznacza oczekiwane parametry filmu olejowego, a w przypadku jego braku, prowadzącego do bezpośredniego kontaktu mikro-nierówności tłoka i cylindra - pomijalne zużycie ścierne warstwy CNT i/lub gładzi cylindra.

12

Effect Of Carbon Nanotubes On The Properties Of Spark Plasma Sintered ZrO2/CNT Composites

Shim D. H., Jung S. S., Kim H. S., Cho H., Kim J. K., Kim T. G., Yoon S. J.

Archives of Metallurgy and Materials

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2015

|

Vol. 60, iss. 2B

1315--1318

EN

Zirconia matrix ZrO2/CNT composite materials reinforced with multiwall carbon nanotubes were fabricated using a spark plasma sintering technique. The effects of the amount of CNTs addition, sintering temperature and sintering pressure on the properties of the resulting ZrO2/CNT composites were examined. 0 to 9 vol. % CNTs were dispersed in zirconia powder, and the resulting mixture was sintered. The electrical conductivity, hardness, flexural strength, and density were measured to characterize the composites. The friction and wear properties of the composites were also tested. The flexural strength and friction coefficient of the composites were improved with up to 6 vol.% of CNT addition and the flexural strength showed a close relationship with the relative density of the composite. The electrical conductivity increased with increasing proportion of the CNTs, but the efficiency was reduced at more than 6 vol.% CNTs.

13

Tribological behaviours of lubricating oils with CNT and Si3N4 nanoparticle additives

Col M.N., Celik O.N., Sert A.

Archives of Materials Science and Engineering

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2014

|

Vol. 67, nr 2

53--59

EN

The goal of this work is comparative study of lubricants with different content of nanoparticle additive to obtain material with an optimal tribological properties. Design/methodology/approach: The effects of carbon nanotube (CNT) and Si3N4 nanoparticle additives on the lubricated friction and wear behaviour of AISI 4140 steel were investigated. In tribological tests, the amounts of nanoparticles added to base oil (SAE 10W40) were varied. The ball-on-disc configuration of the tribometer was used for wear testing (DIN 50324). Specific wear rate, coefficient of friction, wear scar depth were measured. The wear surfaces were analysed using scanning electron microscopy and surface profilometer. Findings: Results showed that with the addition of nanoparticles, wear rates of AISI 4140 steel were decreased. The best additive content of synthetic oil was 0.05% CNT + 0.05% Si3N4 (mass fraction), and in this case, the friction coefficient and the wear rate were decreased 15.2% and 76.4%, respectively. Research limitations/implications: Obtained lubricants are characterized by tribological and frictional properties but homogeneity of lubricants should be improved because of agglomeration. Farther works will be continued also for different contents of lubricant. Practical implications: Tested lubricants can be applied among in industry where wear and friction properties are important. Originality/value: Nanoparticle additive oils which have excellent tribological properties can be very attractive for automobile industry. New type of lubricant mixture (CNT and Si3N4) is used in the paper.

14

MWCNTs-Pt versus MWCNTs-Re nanocomposites manufacturing method

Dobrzańska-Danikiewicz A., Łukowiec D., Wolany W., Cichocki D.

Archives of Materials Science and Engineering

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2014

|

Vol. 67, nr 1

5--13

EN

Purpose: The primary aim of the article is to compare fabrication methods and present newly fabricated MWCNTs-NPs nanocomposites whose structural components are carbon nanotubes and platinum and rhenium nanoparticles. Design/methodology/approach: The newly fabricated nanocomposites underwent STEM examinations in the bright and dark to show their structure. Raman spectroscopy examinations were carried out, as well, to confirm changes in the structure of carbon nanotubes subject to the experiments. Findings: It was found based on a comparative analysis of the structure of MWCNTs-Pt and MWCNTs-Re nanocomposites that functionalisation methods and a reduction method of precursors of selected noble elements have a significant effect on the structure and morphology of the compared carbon nanocomposites. Practical implications: Nanocomposites consisting of carbon nanotubes decorated with metal nanoparticles, including Pt and Re, possess special electrical properties and a developed specific area, which makes them particularly suitable as active elements of industrial gas sensors. The materials can also be used as biosensors and catalysts in the future. Originality/value: A comparative analysis of the following author’s methods: (i) fabrication of MWCNTs-Pt nanocomposite, which was given numerous awards at international innovation and invention exhibitions and (ii) fabrication of MWCNTs-Re nanocomposite pending patent protection.

15

Wprowadzenie do nanotelekomunikacji

Palider J., Jajszczyk A.

Przegląd Telekomunikacyjny + Wiadomości Telekomunikacyjne

|

2013

|

nr 4

97--103

PL

Opisano ideę nanokomunikacji. Dokonano przeglądu mechanizmów transmisji danych opartych na strukturach węglowych oraz organizmach biologicznych, ich ograniczenia, a także potencjalne korzyści z ich stosowania.

EN

In this article the idea behind nanocommunication was presented. Data transmission mechanisms based on carbon-based structures and living organisms were shown. In each case advantages and disadvantages were pointed out.

16

Thermal Properties of Carbon Nanotube (CNT) Reinforced Polyvinyl Alcohol (PVA) Composites

Hasan M., Das S. K., Islam J. M. M., Gafur Md. A., Hoque E, Khan M. A.

International Letters of Chemistry, Physics and Astronomy

|

2013

|

Vol. 12

59--66

EN

Homogeneous Polyvinyl alcohol (PVA)/Carbon nanotube (CNT) composite has been prepared by solution casting method using gum acacia as a surfactant. CNT content in the composite was varied from 5-10 % by weight. The thermal properties of PVA/CNT composites were investigated by Thermo Gravimetric/Differential Thermal Analyzer (TG/DTA) and Thermo Mechanical Analyzer (TMA). TG/DTA results showed that higher thermal stability in higher percentage of CNT in the composites. The 10 % CNT containing PVA composite exhibit highest onset of melting, glass transition point and offset of melting temperature and the recoded values are 330.4K, 379K and 421.3K respectively. All of the result indicates that the developed PVA/CNT composite might be promising for use in solar cell application.

17

Application of carbon nanotubes (CNT) to design of the strain sensor

Grabowski K., Uhl T., Zbyrad P.

Pomiary Automatyka Kontrola

|

2012

|

R. 58, nr 11

984-986

EN

The aim of this work was to develop a sensor which could be easily applied to the tested material and integrated with it. Therefore, this paper is focused on the development of the Carbon Nanotube - a polymer strain sensor - which should fulfill such requirements. The development of such a sensor is discussed and the test of its performance are presented. Multiwalled CNTs were mixed with polymer and applied to the materials with use of screen printing. The sensor was tested for different types of loads. Manufacturing technology and sensor test results are presented in this work.

PL

W pracy opisano prototyp czujnika zrealizowany przy użyciu nanorurek węglowych oraz epoksydu. Czujnik został naniesiony na badany materiał (kompozyt włókna szklanego) przy użyciu sitodruku. Struktura sensora (rozłożenie nanorurek w epoksydzie) została zbadana przy użyciu mikroskopu elektronowego. Wykazano, że przy stosunkowo dużych zawartościach procentowych (powyżej 7.5%) nanorurki węglowe tworzą zbite skupiska, przy czym mniejsze zawartości procentowe pozwalają na stosunkowo równomierne rozłożenie nanorurek węglowych w epoksydzie. Dodatkowo czujniki zostały poddane badaniom statycznym jak i dynamicznym. Przy badaniach statycznych miało to na celu zbadania odpowiedzi sensora (czy jest zachowana jego liniowość). Przy obciążeniach dynamicznych celem było sprawdzenie czy dochodzi do uszkodzenia struktury sensora przy stosunkowo dużej ilości cykli obciążeń. Zmiany rezystancji zostały porównane ze zmianami odkształceń badanego materiału (uzyskanymi z maszyny wytrzymałościowej). Otrzymano liniowe odpowiedzi czujników zarówno przy małej jak i dużej liczbie cykli obciążeń.

18

Thermal-hydraulic performance of a CNT based pin fin heat sink for electronics cooling

Ismil M. F., Rashid M. A. I., Mahbub M.

International Journal of Applied Mechanics and Engineering

|

2012

|

Vol. 17, no. 4

1149-1162

EN

This paper describes 3D numerical simulation of the fluid flow and heat transfer characteristics in a pin fin heat sink under constant heat flux condition. Carbon nanotube (CNT) is considered as an ideal material for thermal management in electronic packaging because of its extraordinarily high thermal conductivity. Fabricated onto a silicon substrate to form micro-channels, the CNT based cooling fins show high heat dissipation efficiency. The simulation is performed for the Reynolds number from 7 to 60 with channel hydraulic diameter 1.22 mm. The results are used to derive the Nusselt number, pressure drop, thermal resistance etc.

19

Badania mikroskopowe włókien z polilaktydu otrzymanych techniką elektroprzędzenia jako materiałów na rusztowania komórkowe dla inżynierii tkankowej

Socha A., Błażewicz M.

Engineering of Biomaterials

|

2012

|

Vol. 15, no. 115

12--17

PL

Kość jest tkanką pełniącą bardzo ważną rolę w organizmie ludzkim, np. podczas poruszania się czy jako ochrona narządów wewnętrznych. Dzięki dużym zdolnościom regeneracyjnym tkanki kostnej, jej drobne uszkodzenia mogą samoistnie ulec wyleczeniu. Jednakże w przypadku poważniejszych urazów interwencja chirurgiczna staje się konieczna. Mając na uwadze liczne wady tego rozwiązania, w ostatnim czasie na znaczeniu zyskało podejście alternatywne, polegające na zastosowaniu rusztowań komórkowych do regeneracji tkanki kostnej. Celem wspomnianego postępowania jest stworzenie trójwymiarowej struktury umożliwiającej i wspomagającej regenerację tkanki kostnej. Ponieważ struktury porowate otrzymywane w wyniku elektroprzędzenia swoją budową przypominają naturalną kość, stanowią one idealne środowisko do wysiania i namnożenia komórek. W niniejszej pracy, wykorzystując technikę elektroprzędzenia, otrzymano włókna z polilaktydu (PLA) jako materiał na rusztowania komórkowe do regeneracji tkanki kostnej. Ponadto zbadano wpływ takich parametrów procesu jak skład rozpuszczalnika, stężenie polimeru czy dodatek soli na strukturę otrzymywanych włókien. W celu polepszenia właściwości mechanicznych potencjalnych rusztowań komórkowych, otrzymano także nanokompozytowe włókna z PLA z dodatkiem sfunkcjonalizowanych wielowarstwowych nanorurek węglowych (MWCNT). Uzyskane struktury były badane przy pomocy skaningowego mikroskopu elektronowego (SEM).

EN

Bone is a tissue playing crucial role in human body, e.g., during locomotion or by protecting the internal organs. Thanks to bone's high regenerative capacity, its minor injuries may be spontaneously healed. Larger bone defects however need surgical intervention. Considering numerous disadvantages characterising this approach, bone tissue engineered scaffolds have recently gained considerable interest. Its aim is to design a 3D structure which will enable and promote bone regeneration. As porous structures obtained by electrospinning resemble natural bone, they represent a perfect environment for cell attachment and proliferation. In this work polylactide (PLA) nanofibres were electrospun in order to create a scaffold for bone regeneration. The influence of parameters such as solvent composition, polymer concentration or salt addition on the morphology of the electrospun fibres was investigated in this work. In order to improve scaffold's mechanical properties we manufactured a nanocomposite of PLA and functionalized multiwall carbon nanotubes (MWCNT) using electrospinning technique as well. The obtained scaffolds were examined using scanning electron microscope (SEM).

20

Numerical study of the interface heat transfer characteristics of micro-cooler with CNT structures

Zhang Y., Wang S., Ma S., Hu Z., Liu J., Sitek J., Janeczek K.

Elektronika : konstrukcje, technologie, zastosowania

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2012

|

Vol. 53, nr 1

17-19

EN

Micro-cooling techniques provide a promising solution for the thermal management of electronics system with increasing microprocessor powers. Carbon nanotubes (CNTs) can be utilized in micro-coolers as basic materials to constitute the heat dissipation structures inside. The interfaces involved in the CNT-based micro-cooler include the one between the CNT and the coolant, and the CNT and the adhesive. The heat transfer through these interfaces plays an important role in the thermal performance of the micro-cooler. In this paper, numerical investigations on thermal resistance across interfaces between the CNT and other materials are carried out by molecular dynamics simulation (MDS), and various cases are studied.

PL

Technika mikrochłodzenia stanowi obiecujące rozwiązanie w zarządzaniu ciepłem systemów elektronicznych wraz ze wzrostem mocy mikroprocesorów. Nanorurki węglowe (CNTs) mogą być wykorzystane w mikroradiatorach, jako podstawowy material służący do tworzenia struktur rozpraszających ciepło w ich wnętrzu. Interfejsami w mikroradiatorach opartych na CNTs są obszary między CNT i substancją chłodzącą oraz między CNT i klejem. Transfer ciepla przez te interfejsy ma istotny wpływ na wydajność mikroradiatora. W artykule ukazano wyniki analiz numerycznych transferu ciepła przez interfejsy pomiędzy CNT i innymi materiałami przeprowadzone za pomocą symulacji dynamiki molekularnej (MDS) dla różnych przypadków.