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de Sousa RR, Heinze DA, Sacramento JB, Lanfredi AJC, Carastan DJ. Electrical Conductivity and In Situ SAXS Probing of Block Copolymer Nanocomposites Under Mechanical Stretching. ACS Appl Mater Interfaces 2023. [PMID: 37235644 DOI: 10.1021/acsami.3c03573] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Elastomers based on block copolymers can self-organize into ordered nanoscale structures, making them attractive for use as flexible conductive nanocomposites. Understanding how ordered structures impact electrical properties is essential for practical applications. This study investigated the morphological evolution of flexible conductive elastomers based on polystyrene-b-poly(ethylene-co-butylene)-b-polystyrene (SEBS) block copolymers with aligned single- or multi-wall carbon nanotubes (SWCNTs or MWCNTs) and their electrical conductivity under large deformations. Oriented nanocomposites were obtained through injection molding and characterized using two different setups: tensile testing monitored by in situ small-angle X-ray scattering (SAXS) and tensile testing with simultaneous electrical conductivity measurements. Our findings demonstrate that structural orientation significantly influences electrical conductivity, with higher conductivity in the longitudinal direction due to the preferred orientation of carbon nanotubes. Tensile testing demonstrated that carbon nanotubes accelerate the process of realignment of the ordered structure. As a consequence, higher deformations reduced the conductivity of samples with longitudinal alignment due to the disruption of percolation contacts between nanotubes, while in samples with a transverse alignment the process promoted the formation of a new conductive network, increasing electrical conductivity.
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Affiliation(s)
- Rogerio R de Sousa
- Center for Engineering, Modeling and Applied Social Sciences, Federal University of ABC (UFABC), Av. Dos Estados, 5001, Santo André, São Paulo 09210-580, Brazil
| | - Daniel A Heinze
- Center for Engineering, Modeling and Applied Social Sciences, Federal University of ABC (UFABC), Av. Dos Estados, 5001, Santo André, São Paulo 09210-580, Brazil
| | - Joana B Sacramento
- Center for Engineering, Modeling and Applied Social Sciences, Federal University of ABC (UFABC), Av. Dos Estados, 5001, Santo André, São Paulo 09210-580, Brazil
| | - Alexandre J C Lanfredi
- Center for Engineering, Modeling and Applied Social Sciences, Federal University of ABC (UFABC), Av. Dos Estados, 5001, Santo André, São Paulo 09210-580, Brazil
| | - Danilo J Carastan
- Center for Engineering, Modeling and Applied Social Sciences, Federal University of ABC (UFABC), Av. Dos Estados, 5001, Santo André, São Paulo 09210-580, Brazil
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da Silva DJ, Gramcianinov GB, Jorge PZ, Malaquias VB, Mori AA, Hirata MH, Lopes SAM, Bueno LA, Champeau M, Carastan DJ. PVC containing silver nanoparticles with antimicrobial properties effective against SARS-CoV-2. Front Chem 2023; 11:1083399. [PMID: 36993814 PMCID: PMC10042293 DOI: 10.3389/fchem.2023.1083399] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2022] [Accepted: 02/23/2023] [Indexed: 03/16/2023] Open
Abstract
Poly (vinyl chloride) (PVC) is commonly used to manufacture biomedical devices and hospital components, but it does not present antimicrobial activity enough to prevent biofouling. With the emergence of new microorganisms and viruses, such as Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) that was responsible for the global pandemic caused by Coronavirus Disease 2019 (COVID-19), it is evident the importance of the development of self-disinfectant PVC for hospital environments and medical clinics where infected people remain for a long time. In this contribution, PVC nanocomposites with silver nanoparticles (AgNPs) were prepared in the molten state. AgNPs are well-known as antimicrobial agents suitable for designing antimicrobial polymer nanocomposites. Adding 0.1 to 0.5 wt% AgNPs significantly reduced Young’s modulus and ultimate tensile strength of PVC due to the emergence of microstructural defects in the PVC/AgNP nanocomposites, but the impact strength did not change significantly. Furthermore, nanocomposites have a higher yellowness index (YI) and lower optical bandgap values than PVC. The PVC/AgNP nanocomposites present virucidal activity against SARS-CoV-2 (B.1.1.28 strain) within 48 h when the AgNP content is at least 0.3 wt%, suitable for manufacturing furniture and hospital equipment with self-disinfectant capacity to avoid secondary routes of COVID-19 contagion.
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Affiliation(s)
- Daniel J. da Silva
- Center for Engineering, Modeling, and Applied Social Sciences (CECS), Federal University of ABC (UFABC), Santo André, SP, Brazil
| | - Guilherme B. Gramcianinov
- Center for Engineering, Modeling, and Applied Social Sciences (CECS), Federal University of ABC (UFABC), Santo André, SP, Brazil
| | - Pamela Z. Jorge
- Center for Engineering, Modeling, and Applied Social Sciences (CECS), Federal University of ABC (UFABC), Santo André, SP, Brazil
| | - Vanessa B. Malaquias
- Department of Clinical and Toxicological Analysis, Faculty of Pharmaceutical Sciences, University of São Paulo, São Paulo, SP, Brazil
| | - Augusto A. Mori
- Department of Clinical and Toxicological Analysis, Faculty of Pharmaceutical Sciences, University of São Paulo, São Paulo, SP, Brazil
| | - Mário H. Hirata
- Department of Clinical and Toxicological Analysis, Faculty of Pharmaceutical Sciences, University of São Paulo, São Paulo, SP, Brazil
| | - Sergio A. M. Lopes
- BRGoods Indústria e Comércio de Produtos Hospitalares, Indaiatuba, SP, Brazil
| | - Luciano A. Bueno
- Center for Engineering, Modeling, and Applied Social Sciences (CECS), Federal University of ABC (UFABC), Santo André, SP, Brazil
| | - Mathilde Champeau
- Center for Engineering, Modeling, and Applied Social Sciences (CECS), Federal University of ABC (UFABC), Santo André, SP, Brazil
- *Correspondence: Mathilde Champeau, ; Danilo J. Carastan,
| | - Danilo J. Carastan
- Center for Engineering, Modeling, and Applied Social Sciences (CECS), Federal University of ABC (UFABC), Santo André, SP, Brazil
- *Correspondence: Mathilde Champeau, ; Danilo J. Carastan,
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Abstract
Microencapsulation of curing agents is a major strategy for the development of self-healing polymers. Isocyanates are among the most promising compounds for the development of one-part, catalyst free, self-healing materials, but their microencapsulation is challenging due to their high reactivity. To keep the healing agent intact in the liquid state and containing free-NCO groups, the monitoring of several synthesis parameters is essential. This review aims to summarise the outcomes in the microencapsulation of isocyanates, emphasising the efforts reported in the literature to modulate the microcapsule properties. In this regard, the main synthesis procedures are presented, followed by the most relevant characterisation methods used to assess microcapsule properties. The correlation between these properties and synthesis parameters is also discussed, and finally the main potential and challenges for industrial applications are highlighted.
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Affiliation(s)
- Amanda N B Santos
- Nanoscience and Advanced Materials Graduate Program (PPG-Nano), Federal University of ABC (UFABC), Santo André, Brazil
| | - Demetrio J Dos Santos
- Nanoscience and Advanced Materials Graduate Program (PPG-Nano), Federal University of ABC (UFABC), Santo André, Brazil.,Material Science and Engineering Graduate Program (PPG-CEM), Federal University of ABC (UFABC), Santo André, Brazil
| | - Danilo J Carastan
- Nanoscience and Advanced Materials Graduate Program (PPG-Nano), Federal University of ABC (UFABC), Santo André, Brazil.,Material Science and Engineering Graduate Program (PPG-CEM), Federal University of ABC (UFABC), Santo André, Brazil
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Carastan DJ, Amurin LG, Craievich AF, Gonçalves MDC, Demarquette NR. Clay-containing block copolymer nanocomposites with aligned morphology prepared by extrusion. POLYM INT 2013. [DOI: 10.1002/pi.4480] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Affiliation(s)
- Danilo J. Carastan
- Centro de Engenharia, Modelagem e Ciências Sociais Aplicadas; Universidade Federal do ABC (UFABC); Santo André SP Brazil
| | - Leice G. Amurin
- Metallurgical and Materials Engineering Department, Escola Politécnica; University of São Paulo (USP); Av. Prof. Mello Moraes 2463, Cidade Universitária São Paulo SP Brazil 05508-030
| | - Aldo F. Craievich
- Department of Applied Physics, Institute of Physics; University of São Paulo (USP); São Paulo SP Brazil
| | | | - Nicole R. Demarquette
- Metallurgical and Materials Engineering Department, Escola Politécnica; University of São Paulo (USP); Av. Prof. Mello Moraes 2463, Cidade Universitária São Paulo SP Brazil 05508-030
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Oliveira CFDP, Demarquette NR, Carastan DJ, Fechine GJM. Fotodegradação de compósitos de poliestireno/argila montmorilonita: efeito do tipo de argila e presença de sal. Polímeros 2012. [DOI: 10.1590/s0104-14282012005000010] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Compósitos de poliestireno/montmorilonita (PS/MMT) contendo 2,5% em peso de argila foram preparados com dois tipos de argila modificada com sais quaternários de amônio. Também foram preparadas amostras do PS + sal quaternário de amônio, utilizando-se proporção de sal semelhante à usada na modificação da argila. Todas as amostras foram expostas à radiação UV por períodos de até 12 semanas, e em seguida foram realizados testes para avaliar as modificações em massa molar, propriedades mecânicas (tração e impacto), estrutura química (FTIR) e superfície de fratura (MEV) dessas amostras. Os resultados mostraram que compostos metálicos existentes na argila catalisam o processo fotodegradativo do PS e a presença isolada do sal não altera significativamente o comportamento do PS frente à radiação UV.
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