Universidad Autónoma de Nuevo León, Facultad de Ciencias Físico-Matemáticas, Ave. Universidad, San Nicolás de los Garza, N.L., C.P. 66455, Mexico.
Universidad Autónoma de Nuevo León, Facultad de Ingeniería Civil, Ave. Universidad, San Nicolás de los Garza, N.L., C.P. 66455, Mexico.
Recent Pat Nanotechnol. 2021;15(1):47-54. doi: 10.2174/1872210514666200626165916.
In this work, a detector based on optical fiber covered with Multi-Wall Carbon Nanotubes (MWCNTs) was used for sensing and removal of Alizarin from wastewaters. Alizarin is a strong anionic red dye that is part of the anthraquinone dye group. As a rule, this dye is used in the textile industry as a coloring agent. Experiments showed a good efficiency of wastewater treatment. This development could resolve the problem of water contamination with Alizarin red dye.
We used a single-mode fiber SMF-28e with a core diameter of 8.2 μm and a cladding diameter of 125 μm as a base for the tapered optical fiber detector. An MWCNTs array was synthesized on the tapered optical fiber detector surface by spray pyrolysis Chemical Vapor Deposition (CVD) method at 800oC for 20 min inside a tubular furnace, using ferrocene solution in toluene as a catalyst precursor. The formed structure was applied for Alizarin detection in water.
According to the patent studies, the nanotubes completely covered the optical fiber surface and the array had a high density with minimal distance between nearby nanotubes. Carbon nanotubes were oriented along the radius of the optical fiber. The average diameter of carbon nanotubes was 24 nm. The optical absorbance levels increased as the Alizarin concentration increased from 50 mg/L to 1000 mg/L. MWCNTs on the optical fiber tapered section adsorbed the dye molecules from aqueous solution. Three intensive absorption bands with the wavelength of the 700, 714 and 730 nm appeared and their intensity increased as the Alizarin concentration increased. The accumulated Alizarin can be recovered by multiple immersing clean water. This property may make tapered optical fiber detector reusable and increase the economic expediency of the sensor application.
The study showed higher Alizarin adsorption efficiency of the tapered optical fiber detector compared with relative detectors. This structure can be reusable for dye detection. Removal efficiency for Alizarin reached 98.6%, which makes the tapered optical fiber detector promising for wastewater treatment and dye elimination.
在这项工作中，使用了一种基于涂覆有多壁碳纳米管（MWCNTs）的光纤的探测器，用于感测和去除废水中的茜素红。茜素红是一种强阴离子红色染料，是蒽醌染料组的一部分。通常，这种染料在纺织工业中用作着色剂。实验表明，废水处理的效率很高。这种发展可以解决茜素红染料污染水的问题。
我们使用单模光纤 SMF-28e 作为锥形光纤探测器的基础，其芯径为 8.2μm，包层直径为 125μm。在管式炉中，于 800℃下通过喷雾热解化学气相沉积（CVD）法在锥形光纤探测器表面合成 MWCNTs 阵列，使用甲苯中的二茂铁溶液作为催化剂前体，反应时间为 20min。所形成的结构用于水中茜素红的检测。
根据专利研究，纳米管完全覆盖了光纤表面，并且该阵列具有高密度，相邻纳米管之间的距离最小。碳纳米管沿光纤的半径方向取向。随着茜素红浓度从 50mg/L 增加到 1000mg/L，光吸收水平增加。光纤锥形部分上的 MWCNTs 从水溶液中吸附染料分子。随着茜素红浓度的增加，出现了三个强度较大的吸收带，其波长分别为 700nm、714nm 和 730nm，其强度增加。通过多次浸入清洁水可以回收累积的茜素红。这种性质可能使锥形光纤探测器可重复使用，并提高传感器应用的经济效率。
研究表明，与相对检测器相比，锥形光纤探测器对茜素红的吸附效率更高。这种结构可重复用于染料检测。茜素红的去除效率达到 98.6%，这使得锥形光纤探测器有望用于废水处理和染料去除。
