Sandra Lepak-Kuc

Dr. Sandra Lepak-Kuc

Warsaw University of Technology, Warsaw, Mazowieckie, Poland

Research Focus & Metrics

Academic Career Length

8Years (2019-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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8 August 2019 in ACS Applied Materials & Interfaces
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Journal Article
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Sandra Lepak-KucSandra Lepak-Kuc
Sandra Lepak-Kuc
KMKarolina Z. Milowska
Karolina Z. Milowska
SBSlawomir Boncel
Slawomir Boncel
MSMiroslaw Szybowicz
Miroslaw Szybowicz
ADAnna Dychalska
Anna Dychalska
ALAgnieszka Lekawa-Raus
Agnieszka Lekawa-Raus

9 September 2019 in Nanomaterials
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Journal Article
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Sandra Lepak-KucSandra Lepak-Kuc
Sandra Lepak-Kuc
BPBartłomiej Podsiadły
Bartłomiej Podsiadły
ASAndrzej Skalski
Andrzej Skalski
DJDaniel Janczak
Daniel Janczak
Małgorzata JakubowskaMałgorzata Jakubowska
Małgorzata Jakubowska
ALAgnieszka Lekawa-Raus
Agnieszka Lekawa-Raus
The following paper presents a simple, inexpensive and scalable method of production of carbon nanotube-polyurethane elastomer composite. The new method enables the formation of fibers with 40% w/w of nanotubes in a polymer. Thanks to the 8 times higher content of nanotubes than previously reported for such composites, over an order of magnitude higher electrical conductivity is also observed. The composite fibers are highly elastic and both their electrical and mechanical properties may be easily controlled by changing the nanotubes content in the composite. It is shown that these composite fibers may be easily integrated with traditional textiles by sewing or ironing. However, taking into account their light-weight, high conductivity, flexibility and easiness of molding it may be expected that their potential applications are not limited to the smart textiles industry.

14 September 2021 in Materials
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Journal Article
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Sandra Lepak-KucSandra Lepak-Kuc
Sandra Lepak-Kuc
MKMateusz Kiciński
Mateusz Kiciński
PMPrzemyslaw P. Michalski
Przemyslaw P. Michalski
KPKrystian Pavlov
Krystian Pavlov
Mauro GiorcelliMauro Giorcelli
Mauro Giorcelli
Małgorzata JakubowskaMałgorzata Jakubowska
Małgorzata Jakubowska
Carbon materials are becoming crucial in several industrial sectors. The drawbacks of these materials include their high cost and oil-based essence. In recent years, recycled materials have become possible alternative sources of carbon with several advantages. Firstly, the production of this alternative source of carbon may help to reduce biomass disposal, and secondly, it contributes to CO2 sequestration. The use of carbon derived from recycled materials by a pyrolysis treatment is called biochar. Here, we present composite materials based on different biochar filler contents dispersed in several thermoplastic polymer matrixes. Electrical conductivity and tensile break strength were investigated together with the material characterisation by DTA/TGA, XRD, and scanning electron microscopy (SEM) imaging. Materials with good flexibility and electrical conductivity were obtained. The local ordering in composites resembles both biochar and polymer ordering. The similarity between biochar and carbon nanotubes’ (CNTs) XRD patterns may be observed. As biochar is highly cost-effective, the proposed composites could become a valid substitute for CNT composites in various applications.

2 March 2024 in Polymers
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Jerzy SzalapakJerzy Szalapak
Jerzy Szalapak
BZBartosz Zdanikowski
Bartosz Zdanikowski
AKAleksandra Kądziela
Aleksandra Kądziela
Sandra Lepak-KucSandra Lepak-Kuc
Sandra Lepak-Kuc
LDLucja Dybowska-Sarapuk
Lucja Dybowska-Sarapuk
Małgorzata JakubowskaMałgorzata Jakubowska
Małgorzata Jakubowska
The authors explore the development of paper-based electronics using carbon-based composites with a biodegradable matrix based on ethyl cellulose and dibasic ester solvent. The main focus is on screen-printing techniques for creating flexible, eco-friendly electronic devices. This research evaluates the printability with the rheological measurements, electrical properties, flexibility, and adhesion of these composites, considering various compositions, including graphene, graphite, and carbon black. The study finds that certain compositions offer sheet resistance below 1 kΩ/sq and good adhesion to paper substrates with just one layer of screen printing, demonstrating the potential for commercial applications, such as single-use electronics, flexible heaters, etc. The study also shows the impact of cyclic bending on the electrical parameters of the prepared layers. This research emphasizes the importance of the biodegradability of the matrix, contributing to the field of sustainable electronics. Overall, this study provides insights into developing environmentally friendly, flexible electronic components, highlighting the role of biodegradable materials in this evolving industry.

13 August 2024 in Scientific Reports
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Journal Article
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Sandra Lepak-KucSandra Lepak-Kuc
Sandra Lepak-Kuc
AKAleksandra Kądziela
Aleksandra Kądziela
MSMonika Staniszewska
Monika Staniszewska
DJDaniel Janczak
Daniel Janczak
MJMałgorzata Jakubowska
Małgorzata Jakubowska
ZŻZuzanna Żołek-Tryznowska
Zuzanna Żołek-Tryznowska
Environmental concerns and climate protection are gaining increasing emphasis nowadays. A growing number of industries and scientific fields are involved in this trend. Sustainable electronics is an emerging research strand. Environmentally friendly and biodegradable or biobased raw materials can be used for the development of green flexible electronic devices, which may serve to reduce the pollution generated by plastics and electronics waste. In this work, we present cytocompatible, electrically conductive structures of nanocarbon water-soluble composites based on starch films. To accomplish this goal, potato starch-based films with glycerol as a plasticiser were developed along with a water-soluble vehicle for nanocarbon-based electroconductive pastes specifically dedicated to screen printing technology. Films were characterized by optical microscopy, scanning electron microscopy (SEM) mechanical properties and surface free energy.

29 July 2024 in MRS Bulletin
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Journal Article
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Sandra Lepak-KucSandra Lepak-Kuc
Sandra Lepak-Kuc
ŁNŁukasz Nowicki
Łukasz Nowicki
ALAgnieszka Lekawa-Raus
Agnieszka Lekawa-Raus
MJMalgorzata Jakubowska
Malgorzata Jakubowska
Addressing the growing demand for conductive and flexible composites, this research focuses on producing thermoplastic composite fibers made of polyurethane and carbon nanomaterials featuring the highest possible electrical conductivity. Based on a recently developed methodology enabling the formation of very high filler contents of 40% w/w, this work presents a systematic investigation of the role of all the materials used during the manufacturing process and selects the materials that ensure the best electrical performance. The results show that the highest electrical conductivity and current-carrying capacities are obtained when dimethylformamide is used as a solvent, and small amounts of AKM surfactant aid the de-agglomeration of carbon nanomaterials. It is also shown that the hybridization of MWCNTs filler with graphene nanoplatelets and small amounts of carbon black is beneficial for the electrical properties. However, the highest performance is achieved with SWCNTs as fillers, exhibiting two orders of magnitude higher electrical conductivities of 6.17 × 104 S/m. Impact statement: The article presents a pioneering exploration into the synthesis and application of a novel composite material. This research significantly impacts the field of electromaterials by introducing a cutting-edge approach that leverages the synergistic properties of carbon nanotubes, graphene, and carbon black within a single filament. The impact of this research extends beyond the laboratory, influencing the development of next-generation materials that bridge the gap between conventional materials and advanced nanomaterials. The presented composite filaments open avenues for the creation of innovative devices and systems that demand good mechanical strength, electrical conductivity, and thermal stability. Moreover, the versatility of these filaments allows for the optimization of materials properties, enabling customization based on specific application requirements. In addition to its technological significance, the paper contributes to sustainability efforts by facilitating the production of lightweight, energy-efficient materials. The insights provided by this research have the potential to reshape the landscape of materials science, inspiring further exploration and innovation in the quest for versatile and high-performance electromaterials. Graphical