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1

Investigation of the Effect of Needle Diameter and the Solution Flow Rate on Fiber Morphology in the Electrospinning Method

Gündüz Gonca Şimşek

Fibres & Textiles in Eastern Europe

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2023

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Vol. 31, no. 4

22--29

EN

In the study, the morphological properties of polyacrylonitrile (PAN) fibers produced by electrospinning at different needle diameters and solution flow rates were investigated. For this purpose, 20G and 22G diameter needles were used. The fibres were produced at flow rates of 0.5 ml/hr, 1 ml/hr and 1.5 ml/hr. Scanning electron microscopy (SEM) was used to measure nanofiber diameters. Statistical analyzes were made with the help of the SPSS program. It was observed that finer fibers were obtained as the needle diameter decreased. As the solution flow rate increased, thicker fibers were obtained. In addition, it was observed that the needle diameter and flow rate affect the fiber arrangement and interfiber spacing.

2

The analysis of surface morphology, band gaps and optical properties of PAN/GO thin films

Matysiak W., Adamczyk K.

Archives of Materials Science and Engineering

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2020

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Vol. 101, nr 2

49--56

EN

Purpose: PAN/GO nanocomposites are gaining more and more interest from research and industrial environments. According to theoretical studies and experimental tests, PAN/ GO exhibits excellent properties such as tensile strength, good thermal and electrical conductivity, excellent thermal and tribological properties. Thanks to this property, the composite is considered the ideal successor to the nanocomposites used so far. The PAN/GO nanocomposite has great potential in the filtration, automotive, electrical and photovoltaic industry. Design/methodology/approach: The spin-coating process is used to produce thin layers by centrifuging a liquid substance on flat surfaces. The advantages of the spin- coating process are simplicity and ease with which the process can be carried out. Due to the ability to high spin speeds, high airflow leads to fast drying time, which in turn results in high consistency in both macroscopic and nanometre scales. The spin-coting method is usually the starting point and reference point for most academic and industrial processes that require a thin and uniform coating. The use of spin coating has a wide spectrum. This technique can be used to coat small substrates (from a few square mm) up to the coating of flat displays, e.g. TV sets, which may have a meter or more in diameter. Findings: Among the existing methods for producing thin layers, including physical and chemical methods for gas phase deposition or the self-assembly process, the spin-coating process makes it possible to produce uniform thin nanocomposite layers in an easy and cheap way. Spin coating is usually the starting point and reference point for most academic and industrial processes that require a thin and uniform coating. The advantage of the method is the wide spectrum of use. It is used for coating substrates with everything from photoresists, insulators, organic semiconductors, synthetic metals, nanomaterials, metal precursors and metal oxides, transparent conductive oxides and many other materials. Often, spin coating is used to unravel polymer layers or photoresist on semiconductor substrates. Research limitations/implications: Due to the ongoing research on the potential applications of PAN/GO thin layers, including electronics, automotive and photovoltaics, it is worth trying to optimize the parameters of the spin-coiling process such as rotational speed or duration of the process. It is also worth trying to optimize the concentration of GO in the nanocomposite. Practical implications: Despite mixing the solution with an ultrasonic homogenizer to disperse the nanoparticles, the particles dispersed to form a rough surface. Originality/value: Low-cost, easy to carry out method of producing thin nanocomposite layers, having significant application in laboratory environments.

3

Water Vapor Permeability through PAN Nanofiber Mat with Varying Membrane-Like Areas

Sabantina Lilia, Hes Lubos, Mirasol José Rodríguez, Cordero Tomás, Ehrmann Andrea

Fibres & Textiles in Eastern Europe

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2019

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Vol. 27, no. 1 (133)

12--15

EN

Electrospinning can be used to create nanofiber mats from diverse polymers which can be used as filters etc. Depending on the spinning parameters, also nano-membranes, i.e. non-fibrous mats, can be produced as well as mixtures from both morphologies. The ratio of membrane to fibrous areas can be tailored by the distance between the high voltage electrode and substrate. Here the impact of the mat morphology on the water vapour permeability through polyacrylonitrile nanofiber mats with different membrane-like areas is shown, allowing for tailoring the permeability between 0.1 Pa m²/W and more than 10 Pa m²/W. In this way it is possible to create the finest filters as well as nearly impenetrable thin membranes with the same technology.

PL

Elektroprzędzenie można stosować do tworzenia mat z nanowłókien z różnorodnych polimerów, które mogą być stosowane jako filtry itp. W zależności od parametrów przędzenia, można wytwarzać także nanobłonki, tj. maty niewłókniste, jak również ich hybrydy. Stosunek powierzchni membrany do części włóknistej może być regulowany przez odległość między elektrodą wysokiego napięcia a podłożem. W pracy pokazano wpływ morfologii maty na przepuszczalność pary wodnej poprzez poliakrylonitrylowe maty z nanowłókien z obszarami membranopodobnymi, pozwalając dostosować przepuszczalność między 0,1 Pa·m²/W i ponad 10 Pa·m²/W. Dzięki temu sposobowi możliwe jest tworzenie najlepszych filtrów, a także prawie nieprzeniknionych cienkich membran z zastosowaniem tej samej technologii.

4

Structure and properties of polyacrylonitrile/polystyrene and carbon nanoparticle-based nanocomposite foams

Kausar A.

Advances in Materials Science

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2019

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Vol. 19, nr 1(59)

5--20

EN

In this study, novel polyacrylonitrile/polystyrene (PAN/PS) blend has been prepared and reinforced with carbon nanoparticle to form polyacrylonitrile/polystyrene/carbon nanoparticle (PAN/PS/CNP) nanocomposite foam. Acid-functional carbon nanoparticle (0.1-3 wt.%) was used as nano-reinforcement for PAN/PS blend matrix. 2’-azobisisobutyronitrile was employed as foaming agent. The PAN/PS/CNP nanocomposite foams have been tested for structure, morphology, mechanical properties, thermal stability, non-flammability, water uptake, and toxic ion removal. Field-emission scanning electron microscopy and transmission electron microscopy exposed unique nanocellular morphology owing to physical interaction between the matrix and functional CNP. PAN/PS/CNP 0.1 Foam with 0.1 wt.% nanofiller had compression strength, modulus, and foam density of 41.8 MPa, 22.3 GPa, and 0.9 mgcm−3, respectively. Nanofiller loading of 3wt.% (PAN/PS/CNP 3 Foam) considerably enhanced the compression strength, modulus, and foam density as 68.2 MPa, 37.7 GPa, and 1.9 mgcm−3, respectively. CNP reinforcement also enhanced the initial weight loss and maximum decomposition temperature of PAN/PS/CNP 3 Foam to 541 and 574 ºC, relative to neat foam (T0 = 411 ºC; T10 = 459 ºC). Nanocomposite foams have also shown excellent flame retardancy as V-0 rating and high char yield of up to 57% were attained. Due to hydrophilic nature of functional carbon nanoparticle, water absorption capacity of 3 wt.% nanocomposite foam was 30% higher than that of pristine foam. Moreover, novel foams were also tested for the removal of toxic Pb2+ ions. PAN/PS/CNP 3 Foam has shown much higher ion removal capacity (166 mg/g) and efficiency (99 %) than that of PAN/PS foam having removal capacity and efficiency of 90 mg/g and 45 %, respectively.

5

Analysis of the morphology and properties of PAN/Bi2O3 composite nanomaterials produced by electrospraying method

Tański T., Matysiak W., Markovičová L., Florek-Szotowicz N., Snopiński P., Krzemiński Ł., Wiśniowski M.

Journal of Achievements in Materials and Manufacturing Engineering

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2015

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Vol. 73, nr 2

176--184

EN

Purpose: The aim of the study was the preparation of the composite nanofibers with the polymer matrix reinforced by the reinforcement phase in the form of Bi2O3 ceramic nanoparticles using the electrospinning method from the 10% PAN/DMF solutions with the mass concentration of Bi2O3 nanoparticles of the order of 5 and 10%, and the investigate their morphology and physical properties as a function of the mass concentration of the reinforcing phase and the applied process parameters. Design/methodology/approach: In order to analyze the structure of the used Bi2O3 nanoparticles were used high-resolution transmission electron microscope (TEM) and X-ray diffraction analysis (XRD). To examine the morphology and chemical composition of the resulting of materials was carried out using a scanning electron microscope (SEM) with energy dispersive spectrometer (EDS). In order to analyze the physical properties of obtained composite materials was made the UV-VIS spectroscopy study, which are then used to determine the band structure of the obtained nanocomposite materials and to determine the effect of mass concentration of the reinforcing phase on the value of the energy band gap. Findings: The influence of parameters of the electrospinning process on morphology of the composite materials and influence of mass concentration of reinforcing phase on electrical structure obtained materials were determined. Practical implications: Analysis of the electrical properties resulting composite material showed that the PAN composite material reinforced ceramic Bi2O3 nanoparticles is a potentially attractive dielectric material which may be used in the field of optoelectronics. Originality/value: The Bi2O3 particles, due to their energy structure and the photocatalytic properties applied as the strengthening phase for polymers fibers and particles are attractive alternative for composite materials from PAN/TiO2 used as the photocatalytic and dielectric materials.

6

Solvent Vapour-Sensitive Activated Carbon Submicrofibres Based on Electrospun Polyacrylonitrile Fibre Mat

Gliścińska E.

Fibres & Textiles in Eastern Europe

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2015

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Vol. 23, no. 4 (112)

96--102

EN

Precursor polyacrylonitrile submicrofibres with a diameter of about 900 nm, electrospun from polyacrylonitrile/dimethyl sulfoxide (PAN/DMSO) solution, were carbonised and chemically activated. These submicrofibres, characterised by a porous structure more developed than in the case of standard fibres, were investigated as solvent vapour sensors. Sensitivity to vapours of four different fluids: methanol, acetone, benzene & toluene at a low concentration of 200 ppm, was studied directly for fibres and for ones in a prototype textile multilayer system. In experiments the electrical conductivity of carbon fibres was utilised. The response time and sensority coefficient, indicating quantitative changes in electric resistance due to contact with the solvent vapours, were estimated. The activated carbon submicrofibres are characterised by sensitivity, a very short response time not longer than 20 s, stability, and selectivity in relation to vapours of polar and non-polar solvents. The sensitivity to vapours of polar solvents is higher than that to those of non-polar solvents.

PL

Submikrowłókna poliakrylonitrylowe o średnicy około 900 nm elektroprzędzione z roztworu poliakrylonitrylu w dimetylosulfotlenku (PAN/DMSO), zastosowane jako prekursor, były karbonizowane i aktywowane chemicznie. Aktywne submikrowłókna węglowe, charakteryzujące się bardziej rozwiniętą strukturą porowatą, niż włókna standardowe, badane były jako czujniki oparów rozpuszczalników. Czułość na działanie oparów czterech różnych płynów: metanolu, acetonu, benzenu i toluenu, o niskim stężeniu wynoszącym 200 ppm, badana była bezpośrednio dla warstwy włókien i dla prototypowego systemu wielowarstwowego zawierającego warstwę tych włókien. W przeprowadzonych eksperymentach została wykorzystana przewodność elektryczna włókien węglowych. Oszacowany został czas, po którym następuje reakcja włókien i współczynnik czułości wskazujący ilościowe zmiany rezystancji elektrycznej na skutek kontaktu włókien z oparami rozpuszczalników. Aktywne submikrowłókna węglowe wykazują czułość na obecność oparów, bardzo krótki czas reakcji nie dłuższy niż 20 s, stabilność i selektywność w stosunku do oparów rozpuszczalników polarnych i niepolarnych. Czułość na działanie oparów rozpuszczalników polarnych jest większa, niż czułość na działanie oparów rozpuszczalników niepolarnych.

7

Black Orlon as promising material for bone tissue engineering

Parizek M., Vetrik M., Hruby M., Lisa V., Bacakova L.

Engineering of Biomaterials

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2014

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Vol. 17, no. 128-129

4--6

8

Synthesis of carbon/α-Al2O3 composite adsorbents for the elimination of methyl-ethyl ketone vapour

Kuśtrowski P., Molenda M., Janus R., Kochanowski A., Piwowarska Z.

Polimery

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2010

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T. 55, nr 6

457-460

EN

α-Al2O3 has been modified by the deposition of different amounts of polyacrylonitrile (PAN) via precipitation radical polymerization in an aqueous suspension. Carbonization of the product performed in an inert atmosphere at 350 °C resulted in obtaining of a carbon layer supported on the surface of α-Al2O3. The content of carbon in the composites was determined by temperature-programmed oxidation, whereas textural properties of the synthesized samples were studied by low-temperature sorption of N2 (BET). The carbon/α-Al2O3 composites appeared to be effective adsorbents of methyl ethyl ketone vapour.

PL

Zmodyfikowano powierzchniowo tlenek glinu osadzając na nim w wyniku prowadzonej w wodnej zawiesinie α-Al2O3 rodnikowej polimeryzacji akrylonitrylu różne ilości PAN (2,3; 3,1 lub 3,8 moli PAN na 1 mol tlenku glinu). Badania termograwimetryczne wykonane w przepływie gazu obojętnego (rys. 1) pozwoliły na określenie mechanizmu termicznego rozkładu tak osadzonego PAN oraz na wytypowanie optymalnej temperatury karbonizacji uzyskanych materiałów prekursorowych (350 ° C w argonie). Wyniki temperaturowo-programowanego utlenienia (rys. 2) umożliwiły zdefiniowanie stabilności termicznej karbonizatów w atmosferze powietrza oraz wyznaczenie zawartości w nich węgla; wyniosła ona (w zależności od udziału PAN) 12,8; 25,8 lub 42,1 % mas. C. Zaobserwowano, że zawartość ta jest skorelowana z parametrami teksturalnymi (powierzchnią właściwą oraz całkowitą objętością porów) karbonizowanego materiału (tabela 1). Powierzchnia właściwa wyznaczona metodą BET maleje z 29,1m²/g (niemodyfikowany α-Al2O3) do 13,1m²/g w przypadku próbki z największą zawartością C. Preparaty przetestowano w roli adsorbentów par ketonu metylowo-etylowego (MEK) z powietrza (rys. 3). Stwierdzono wyraźny wzrost efektywności adsorpcji spowodowany obecnością węgla, zwiększającej się wraz ze zwiększaniem zawartości C, do 0,0201g MEK na1g adsorbenta.

9

Influence of Fibre Formation Conditions on the Properties of Nanocomposite PAN Fibres Containing Nanosilver

Mikołajczyk T., Szparaga G.

Fibres & Textiles in Eastern Europe

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2009

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Vol. 17, no. 4 (75)

30--36

EN

The research involved studying the influence of coagulation bath temperature and the asspun draw ratio on the porous structure and strength properties of PAN fibres containing a silver nanoadditive. The fibres produced are characterised by a strength reaching 45 cN/tex and an increased porosity of up to 0.6 cm3/g. These properties are advantageous when such fibres are a precursor for producing carbon fibres for medical purposes.

PL

W pracy zbadano wpływ temperatury kąpieli koagulacyjnej oraz wartości wyciągu filierowego na strukturę porowatą i właściwości wytrzymałościowe włókien PAN zawierających w tworzywie nanododatek srebra. Otrzymane włókna odznaczają się wytrzymałością dochodzącą do 45 cN/tex przy jednocześnie podwyższonej porowatości dochodzącej maksymalnie do 0,6 cm3/g. Właściwości te są korzystne ze względu na przeznaczenie tych włókien jako prekursora do otrzymywania włókien węglowych do zastosowań medycznych.

10

Comparative Analysis of Various Electrospinning Methods of Nanofibre Formation

Cengiz F., Krucińska I., Gliścińska E., Chrzanowski M., Göktepe F.

Fibres & Textiles in Eastern Europe

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2009

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Vol. 17, no. 1 (72)

13--19

EN

In general, nanofibres can be formed using the electrospinning technique, which has been known for a long time in literature. However, there are still some problems related to this technique such as low production rate, capillary clogging, etc. In recent years, several new electrospinning methods have been developed to solve such problems. The main aim of this paper is to present the possibility of nanofibre formation by three various electrospinning methods. In this study nanofibres were produced from PAN/DMSO solution using three different electrospinning methods: a conventional method with one capillary, Jirsak’s method and Yarin & Zussman’s method. The properties of these nanofibres as well as the processing conditions were compared. It was observed that using the last two methods it is possible to increase the production rate because of the multiple jets. In the conventional method a single capillary should be replaced by a spinning head system with many capillaries. Using Jirsak’s method, the nanofibre diameter decreases and a higher amount of fibre is obtained by increasing the rotary speed of the cylinder. Production at 10 wt % polymer concentration by Yarin & Zussman’s method leads to much finer fibres than by other methods.

PL

Nanowłókna formowane mogą być techniką elektroprzędzenia znaną w literaturze już od dłuższego czasu. Jednakże, nadal istnieją pewne problemy związane z tą techniką, jak np. mała wydajność produkcji, zatykanie się kapilar, itd. Ostatnio, w celu rozwiązania tychże problemów, rozwinięte zostały nowe metody elektroprzędzenia. W artykule zaprezentowano możliwości formowania nanowłókien przy użyciu trzech różnych metod elektroprzędzenia: konwencjonalnej metody z jedną kapilarą, metody Jirsaka oraz metody Yarina i Zussmana. Do wytworzenia nanowłókien stosowano roztwór poliakrylonitrylu w dimetylosulfotlenku. Porównane zostały właściwości otrzymanych nanowłókien, jak również warunki procesu ich wytwarzania. Zauważono, że stosując dwie ostatnie metody uzyskać można zwiększenie wydajności procesu dzięki zwielokrotnieniu strumieni polimerowych. W metodzie konwencjonalnej zaś, jedna kapilara powinna być zastąpiona przez system głowicy przędzącej z większą ilością kapilar. Stosując metodę Jirsaka uzyskać można mniejsze średnice nanowłókien, a większą ilość włókien otrzymuje się poprzez zwiększenie prędkości obrotowej cylindra. Najcieńsze włókna uzyskać można z 10%-go roztworu stosując metodę Yarina i Zussmana.

11

A New Polymeric Support for Enzyme Immobilization for Biomicroreactors

Łukowska E., Pijanowska D., Chwojnowski A.

Polish Journal of Chemistry

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2008

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Vol. 82, nr 6

1265-1272

EN

Preparation of three kinds of the modified polyacrylonitrile supports for enzymes used in microreactors is described. The polyacrylonitrile supports were produced using the phase inversion method, with dimethylformamide as a solvent. For conversion of the cyano groups into the carboxylic ones, the raw supports were treated with sodium hydroxide or, alternatively using a new method, with ammonium persulfate. The modified supports were used for urease immobilization. The comparison of the immobilization effectiveness and activity of the immobilized and free enzyme is presented. The effectiveness of urease immobilization was evaluated by two methods, spectrophotometric and potentiometric with use of the flow-through microreactor. It was stated that the two-layer structure films with the polyvinylpyrrolidone, as well as using of the ammonium persulfate for surface modification, made a significant improvement in efficiency of the enzyme immobilization.

12

Comparative Analysis of the Influenceofthe Kind and Amount of Two Ferromagnetic Nanoadditives on the Structural Properties of Precursor Polyacrylonitrile Fibres

Boguń M., Mikołajczyk T., Szparaga G., Kurzak A., Wójcik M

Fibres & Textiles in Eastern Europe

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2008

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Vol. 16, no. 5 (70)

48--53

EN

A comparative analysis of the influence of two different ferromagnetic nanoadditives on the rheological properties of polyacrylonitrile spinning solutions in DMF, as well as on the porous structure and tensile strength properties of nanocomposite fibresobtainedfromthesesolutions, was carried out. A ferromagnetic commercial product of the company Sigma-Aldrich and a product manufactured at the AGH University of Science and Technology, Krakow, Poland were used in this study. The influenceoftheamountofbothtypesofnanoadditives inserted into the fibrematrixontheirstructureandtensilestrengthpropertieswas determined. The uniformity of distribution of the nanoadditive on the fibresurfacewasestimated on the basis of SEM + EDS investigations.

PL

Przeprowadzono analizę porównawczą wpływu dwóch różnych ferromagnetycznych nano dodatków (produktu handlowego firmy Sigma-Aldrich oraz produktu otrzymanego w AGH Kraków) na właściwości reologiczne roztworów poliakrylonitrylu w DMF-ie, strukturę porowatą i właściwości wytrzymałościowe włókien nano kompozytowych uzyskanych z tych roztworów. Określono wpływ ilości obu typów nanododatków wprowadzanych do tworzywa włókien na ich strukturę i właściwości wytrzymałościowe. W oparciu o badania SEM+EDS oceniono równomierność rozłożenia nano dodatku na powierzchni włókien.

13

Influence of the Type of Montmorillonite and the Conditions of Fibre Formation from a Polyacrylonitrile Nanocomposite on the Fibre Properties

Mikołajczyk T., Boguń M., Szparaga G.

Fibres & Textiles in Eastern Europe

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2007

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Vol. 15, no. 3 (62)

25--31

EN

We investigated the influence of the ultrasound disintegration of montmorillonite (MMT) nanoadditions before inserting them into the spinning solution on the structure and properties of fibres spun from a polyacrylonitril (PAN) nanocomposite. The supermolecular structure, the porosity, and the tenacity were characterised, and the distribution of the nanoaddition on the fibre surface was evaluated. The fibres were formed under conditions related to those for manufacturing fibres with a high tensile strength, and alternatively under conditions appropriate for obtaining fibres with increased porosity, but with tensile strength at a level which would enable their further processing by carbonisation in order to obtain carbon fibres.

PL

Zbadano wpływ ultradźwiękowego rozpraszania nanododatku, przed wprowadzeniem do roztworu przędzalniczego, na strukturę i właściwości włókien z nanokompozytu poliakrylonitrylowego (PAN). Scharakteryzowano strukturę nadmolekularną i porowatość, oznaczono wytrzymałość właściwą oraz oceniono rozkład nanododatku na powierzchni włókien. Włókna formowano w warunkach odpowiadających otrzymaniu włókien o wysokiej wytrzymałości oraz alternatywnie w warunkach odpowiadających uzyskaniu włókien o zwiększonej porowatości, przy zachowaniu poziomu wytrzymałości na poziomie umożliwiającym przeprowadzenie procesu karbonizacji.

14

Preliminary Investigation into Carbon Nanofibres for Electrochemical Capacitors

Klata E., Babeł K., Krucińska I.

Fibres & Textiles in Eastern Europe

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2005

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Vol. 13, no. 1 (49)

32--34

EN

This paper presents an investigation into the influence of the parameters of the thermal stabilisation process of polyacrylonitrile (PAN) nanofibres on the process of their pyrolysis. The manufacture of precursor nanofibres by electrospinning from a polyacrylonitrile/N, N-dimethylformamide (PAN/DMF) solution is also described. The diameters of the nanofibres obtained are within the range of 640 nm, whereas their degree of crystallinity, as determined by means of wide angle X-ray scattering, is 40%. The parameters of the thermal stabilisation and the pyrolysis processes of the precursor nanofibres are presented. Two processing variants of the thermal stabilisation of PAN nanofibres in an air stream were applied. The first variant of the stabilisation process was conducted at 225°C for 5-6 h, and the second variant step-wise for 9-10 h in a laboratory chamber dryer at a temperature of up to 280°C. The pyrolysis process was carried out in a thermobalance at a temperature of up to 700°C. Images of PAN precursor nanofibres and of the carbon fibres obtained from them are illustrated by SEM microphotographs.

PL

Artykuł przedstawia badania nad wpływem parametrów procesu stabilizacji termicznej nanowłókien połiakrylonltrylowych na przebieg procesu ich zwęglania. Opisano wytwarzanie nanowłókien prekursorowych poprzez elektro-przędzenie z roztworu poliakrylonitrylu w N,N-dwumetyloformamidzie (PAN/DMF). Średnica otrzymanych włókien była rzędu 640. nm, podczas gdy stopień krystalizacji, określony za pomocą metod)) WAXS, wyttosił 40%, Przedstawiono parametry stabilizacji termicznej i zwęglania prekursorowych nanowłókien w postaci włókniny. Zastosowano dwa warianty procesu stabilizacji termicznej w strumieniu powietrza, Podczas pierwszego wariantu stabilizację prowadzono w temperaturze 225°C przez 5-6 godzin, podczas gdy drugi wariant polegał na wielostopniowym podgrzewaniu przez 9-10 godzin do temperatury 280°C i był prowadzany w laboratoryjnej suszarce komorowej. Zwęglenie prowadzono w termowadze do temperatury 700°C, Przedstawiono mikrozdjęcia nanowłókien prekursorowych i węglowych wykonane za pomocą SEM.

15

Preparation of natural silk waste solutions by high frequency heating

Nabieva I., Sadriddinov B., Khasanova M., Alimova K., Klemola K., Pearson J.

Autex Research Journal

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2004

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Vol. 4, no. 3

143--146

EN

Natural silk waste is an important by-product of the silk industry in Uzbekistan. Solutions to the problem of natural silk waste have been used to improve the properties of the locally produced polyacrylonitrile fibre. Nitron, and the effectiveness of this dissolution process, are very important to the textile industry in Uzbekistan. Previous methods used to dissolve natural silk waste have been time-consuming and relatively inefficient. This paper describes a new method for dissolving natural silk waste, using a high-frequency electromagnetic field.

16

Electrical Conductivity of Heat Treated Polyacrylonitrile and Complexes of Polyacrylonitrile with Transition Metal Chlorides

Al-Gurashi M.

Polish Journal of Chemistry

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2001

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Vol. 75, nr 5

689-698

EN

Polymerization of acrylonitrile (AN), without and in the presence of CuCl2, CoCl2, and NiCl2, formed polyacrylonitrile homopolymer (PAN) and polymer complexes of AN-CuCl2, AN-CoCl2 and AN-NiCl2, respectively. These polymer complexes were characterized using spectroscopic techniques. Electrical conductivity and cyclic voltammetry on untreated and heat treated polymers, carried out at different temperatures, showed that the conductivity increased with temperature, presumably due to conjugation and cyclization during heat treatment.