BR-102024018085-A2 - PROCESS FOR OBTAINING GRAPHIC CARBON AND GRAPHENE NANOPLATELETS FROM CONTROLLED PYROLYSIS OF INDUSTRIAL TEXTILE WASTE AND LIQUID-PHASE EXFOLIATION AND PRODUCTS OBTAINED

Abstract

The present invention relates to obtaining graphitic carbon (GC) and graphene nanoplatelets (NG) from industrial textile waste by means of controlled pyrolysis (E5) and liquid-phase exfoliation. The process involves the preparation and selection (E1) of textile waste, composed of cotton, viscose, acrylic, polyester and elastane fibers, followed by controlled pyrolysis (E5) at a temperature of approximately 1100 °C in a nitrogen atmosphere. After controlled pyrolysis (E5), the material obtained is ground (E6) to achieve an average particle size of 11 μm. Graphene nanoplatelets (NG) are then produced by liquid-phase exfoliation (E9) with ultrasonication, resulting in structures with 5 to 10 layers of carbon atoms. This process stands out for its use of industrial textile waste without the need for prior fiber separation and for the elimination of complex and hazardous steps, such as chemical activation. Graphene nanoplatelets (NG) are highly structured and have potential for various applications in advanced materials, including composites and electronic devices. The present invention provides a sustainable solution for the valorization of textile waste, contributing to the circular economy and reducing the environmental impacts associated with the disposal of these materials.

Inventors

• SAMIA CRISTINA NABHAN
• PAULO ROBERTO DANTAS MARANGONI
• RAFAEL JOSÉ DA SILVA
• DYANA CAROLINA MARQUES SANCHES BRIANESE PORTO
• ALANA CRISTINE PELLANDA
• ANDERSON OLIVEIRA DA SILVA
• EDUARDO PAGANO
• EDUARDO PEREIRA MIRANDA DOS SANTOS
• FRANCYELLE CALEGARI
• NATALIA CRISTINA DA SILVA
• PALOMA LIMA DE OLIVEIRA

Assignees

• SAMIA CRISTINA NABHAN

Dates

Publication Date

20260317

Application Date

20240902

Claims (6)

1. 1. PROCESS FOR OBTAINING GRAPHIC CARBON AND GRAPHENE NANOPLATELETS FROM CONTROLLED PYROLYSIS OF INDUSTRIAL TEXTILE WASTE AND LIQUID-PHASE EXFOLIATION, characterized by comprising the following steps: • Separation and identification of solid textile waste (E1), such waste consisting of cotton fiber, viscose fiber, acrylic fiber, polyester fiber, and elastane fiber; • Physicochemical and investigative analyses of the composition of the different wastes (E2); • Crushing and mixing (E3) of the solid textile waste in a knife mill; • Weighing (E4) of equal masses of the crushed textile waste mixture and homogenization of the mixture again in the knife mill; • Controlled pyrolysis (E5) of the waste mixture at a temperature of 1100 °C for a period of 500 minutes, using a heating rate of 6 °C/minute in a nitrogen atmosphere; • Grinding (E6) of graphitic carbon (GC) in a planetary mill at a speed of 210 RPM for 10 minutes until an average particle size of 11 μm is reached; • Preparation of a graphitic carbon (GC) solution in N,N-dimethylformamide (DMF) with a concentration of 10 mg/mL; • Stirring (E8) of the graphitic carbon (GC) solution for 16 hours at room temperature (25°C) at 300-500 RPM; • Liquid-phase exfoliation (E9) of graphitic carbon (GC) for 6 hours in an ultrasonic bath with a frequency of 40 kHz and a power of 180 W; • Centrifugation (E10) of the solution, at a temperature of 20°C, at a speed of 1000 RPM, for 90 minutes, in a refrigerated centrifuge; • Separation (E11) and obtaining the supernatant graphene nanoplatelets (NG).
2. 2. PROCESS FOR OBTAINING GRAPHITE CARBON AND GRAPHENE NANOPLATELETS FROM CONTROLLED PYROLYSIS OF INDUSTRIAL TEXTILE WASTE AND LIQUID-PHASE EXFOLIATION according to claim 1, characterized by the use of mixtures of solid textile waste as starting material, these being composed of 33% cotton fiber, 29% viscose fiber, 5% acrylic fiber, 32% polyester fiber and 2% elastane, without the need for prior separation of the fibers.
3. 3. PROCESS FOR OBTAINING GRAPHITE CARBON AND GRAPHENE NANOPLATES FROM CONTROLLED PYROLYSIS OF INDUSTRIAL TEXTILE WASTE AND LIQUID-PHASE EXFOLIATION, according to claim 1, characterized by the use of a nitrogen atmosphere during controlled pyrolysis (E5).
4. 4. Obtaining graphene and graphite carbon nanoplatelets according to claim 1, characterized by the quenching of chemical activation steps.
5. 5. Graphitic carbon, obtained according to the process described in claim 1, characterized by having an average particle size of 11 μm.
6. 6. Graphene nanoplatelets, obtained according to the process described in claim 1, characterized by being composed of 5 to 10 layers of carbon atoms, arranged in hexagonal arrays covalently bonded to each other.

Description

BRIEF DESCRIPTION [001] This patent application relates to a “PROCESS FOR OBTAINING GRAPHITE CARBON AND GRAPHENE NANOPLATES FROM CONTROLLED PYROLYSIS OF INDUSTRIAL TEXTILE WASTE AND LIQUID-PHASE EXFOLIATION AND PRODUCTS OBTAINED” which refers to obtaining graphite carbon from mixtures of industrial textile waste, specifically from fabrics composed of cotton, viscose, acrylic, polyester and elastane fibers, and the subsequent obtaining of graphene nanoplatelets from the previously prepared graphite carbon. The object of this invention is to provide a route for obtaining carbon derivatives, initially obtaining graphite carbon with randomly oriented layers in a rhombohedral structure; and, from it, producing graphene nanoplatelets, consisting of 5 to 10 layers of carbon atoms. The present invention describes in detail the steps of the process for obtaining graphitic carbon and graphene nanoplatelets, as well as their resulting physical properties, such as lateral size, thickness, defect density and crystalline organization. FIELD OF APPLICATION [002] The present invention falls within the field of Chemistry, with emphasis on Inorganic Chemistry, and more specifically in the area of carbon-based chemical compositions. This invention describes a method for obtaining graphitic carbon from textile industry waste by means of controlled pyrolysis, which is used as starting material for the production of graphene nanoplatelets. CONVINCING [003] The textile industry is one of the most polluting in the world, contributing significantly to waste generation and environmental degradation. Constant changes in fashion drive increased clothing consumption, resulting in large quantities of textile waste that is often difficult to recycle due to the diversity of fibers used in garments. This complexity makes the process of separating and disposing of materials a significant challenge for the industry. [004] Given this scenario, it is essential to find a sustainable destination for this waste. An innovative alternative is the thermal conversion of textile waste into graphitic carbon and, subsequently, into graphene, without the need for prior separation of the fibers. This solution simplifies the process, reduces costs and risks, and generates a product with greater added value, aligning with the principles of the circular economy. [005] Graphene stands out as a promising material, with applications ranging from electronics to water treatment. Traditionally produced from the mineral graphite, graphene presents high costs and significant environmental impacts during its extraction and purification. Therefore, it is essential to find sustainable alternatives for its production, promoting more sustainable development. In this context, the use of pyrolysis for the conversion of textile waste into graphitic carbon and, subsequently, into graphene is a crucial strategy to solve the challenges faced by industry, society and the environment, while simultaneously adding value to the final product obtained. BACKGROUND OF THE INVENTION [006] In the current state of the art, there are prior art inventions that share common points with the inventive process that will be detailed here. However, it is important to highlight that none of the patent documents located resemble the present invention, since none of them specifically addresses the obtaining of graphitic carbon and subsequent production of graphene nanoplatelets through the thermal recycling of a mixture of industrial textile solid waste. The present invention uses only the controlled pyrolysis process at an optimum temperature of 1100 °C, without the use of chemical reagents, followed by liquid-phase exfoliation of the carbon in an ultrasonic bath to obtain graphene nanoplatelets. [007] Shams and colleagues (2015) in a scientific article published in Materials Letters, entitled “Synthesis of graphene from biomass: A green chemistry approach” present in their study a method for obtaining graphene using camphor sheets through pyrolysis at a temperature of 1200 °C. After the pyrolysis procedure, the sample is mixed with d-tyrosine and dichloromethane for exfoliation. The graphene obtained by the study has few layers, up to a maximum of 7, and an Id/Ig index of 0.99, but without a successful outcome. [008] The present invention differs from the scientific article by Sham et al. (2015) mainly by simplifying the process, in which the pyrolysis process takes place at a milder temperature, does not employ chemical reagents, and uses a different starting biomass for the production of graphene and graphitic carbon. The material obtained in this invention also presents improved physicochemical characteristics compared to that presented in the aforementioned study. [009] US patent document 9181134 B1 describes a process for producing graphite from textile solid waste. The method comprises the steps of preparing the waste, such as washing, separation or shredding, followed by graphitization by