Pego Matheus F F, Bianchi Maria Lúcia, Carvalho Janaína A, Veiga Tais R L A
Departamento de Ciências Florestais, Universidade Federal de Lavras, Campus Universitário, Av. Doutor Sylvio Menicucci, 1001, 37200-000 Lavras, MG, Brazil.
Departamento de Química, Universidade Federal de Lavras, Campus Universitário, Av. Doutor Sylvio Menicucci, 1001, 37200-000 Lavras, MG, Brazil.
An Acad Bras Cienc. 2019 Mar 21;91(1):e20170947. doi: 10.1590/0001-3765201920170947.
Surface modification may lead activated carbon (AC) to take on different properties. This study aimed to promote surface modification of activated carbons using corona treatment (electrical discharge). In this study, powdered commercial activated carbon was used. Activated carbons were subjected to corona treatment at different exposure times (2, 5, 8 and 10 min) at 4.5 cm height from the source. To observe differences promoted by treatment, activated carbons were analyzed by acidity, surface functional groups, Fourier Transform Infrared Spectroscopy (FTIR), elemental analysis (CHN), proximate analysis and thermogravimetry. Corona treatment impacted surface chemistry of activated carbons. There was a trend of increasing surface acidity according to exposure time. There were changes in functional groups, increasing carboxyl acid and decreasing lactone and phenol groups. FTIR analysis showed peaks in the bands at 3500, 1650 and 1300 cm-1. Increase of oxygen content and decrease of carbon content were also found. Immediate analysis followed similar tendency for volatile and fixed carbon content. There were also differences in thermogravimetry analysis. Treated activated carbons were different compared to virgin activated carbon. This difference was performed by surface oxidation. Thus, this study showed that corona treatment caused surface modifications and might impact adsorption process.
表面改性可能会使活性炭（AC）具有不同的性质。本研究旨在通过电晕处理（放电）促进活性炭的表面改性。在本研究中，使用了粉末状商用活性炭。将活性炭在距离源4.5厘米的高度下，于不同暴露时间（2、5、8和10分钟）进行电晕处理。为了观察处理所带来的差异，通过酸度、表面官能团、傅里叶变换红外光谱（FTIR）、元素分析（CHN）、工业分析和热重分析对活性炭进行了分析。电晕处理影响了活性炭的表面化学性质。随着暴露时间的增加，表面酸度呈上升趋势。官能团发生了变化，羧酸增加，内酯和酚类基团减少。FTIR分析显示在3500、1650和1300 cm-1波段出现峰值。还发现氧含量增加而碳含量减少。即时分析对于挥发碳和固定碳含量呈现出类似趋势。热重分析也存在差异。经过处理的活性炭与原始活性炭不同。这种差异是由表面氧化造成的。因此，本研究表明电晕处理导致了表面改性，并且可能会影响吸附过程。
