| 摘要: | 根據環保署之統計資料顯示，廢液主要以有機溶劑為主。若能將有機廢液衍生成可再利用之資源材料，可降低廢棄物處理成本及衍生污染風險。本研究以化學氣相沉 根據環保署之統計資料顯示，廢液主要以有機溶劑為主。若能將有機廢液衍生成可再利用之資源材料，可降低廢棄物處理成本及衍生污染風險。本研究以化學氣相沉積法(Chemical vapor deposition，CVD)，選用常用的乙炔及廢有機溶劑中常見的丙酮及甲苯為碳源。合成Santa Barbara Amorphous-15 (SBA-15)及添加Ni觸媒的Ni-SBA-15作為生成載體，於650~950oC熱解生成碳材。並探討生成載體及生成奈米碳材之物化特性(SEM/TEM、孔隙特性、微量元素分析、微結構鑑定、晶相結構鑑定)，製程中收集並分析產生固液混合物(有機化合物、多環芳香烴(Polycyclic Aromatic Hydrocarbons，PAHs))及產生氣體(揮發性有機物(Volatile Organic Compounds，VOCs)、基準污染物)。此外亦針對載體及生成之碳材對細胞危害進行探討。
SBA-15及Ni-SBA-15之物化特性分析結果顯示，BET比表面積分別為652 m2/g及477 m2/g，孔徑分別為41 ?及56 ?，屬中孔隙材料。外型為小桿狀串聯成束狀，排列整齊的六角結構；不同碳源(乙烯、丙酮及甲苯)生成之碳材之物化特性中，合成所得之碳材皆屬中孔隙材料。
乙炔於各溫度(650、750及850oC)生成之碳材，因孔隙增大，導致比表面積及孔隙體積皆變小。丙酮及甲苯生成於各溫度之碳材比表面積及總孔隙體積則隨生成溫度增加而減少。丙酮生成之碳材孔徑隨溫度增加而增大，甲苯則無明顯差異。奈米碳材之外型鑑定，乙炔搭配Ni-SBA-15於650oC下，可合成捲曲之奈米碳管；丙酮搭配Ni-SBA-15則於各溫度下皆可生成碳管；另甲苯搭配Ni-SBA-15於高溫(850及950oC)，可合成奈米碳管。
製程衍生污染物結果顯示，乙炔主要衍生為固液混合物，而丙酮及甲苯則主要衍生為氣態污染物。廢氣污染物中，各生成條件下多生成BETX(指Benzene、Ethyltoluene、Toluene、Xylene)物種之VOCs，其中又以Benzene為主要產物。且VOCs分析結果顯示，添加Ni觸媒的載體能降低VOCs之生成；固液混合衍生物之PAHs分析結果，乙炔產生的總PAHs中最高。乙炔及丙酮搭配Ni-SBA-15於碳材生成中，衍生的總PAHs皆大於SBA-15，而PAHs主要之物種為Naphthalene及Pyrene。
以A549(肺癌細胞)測試乙炔生成碳材之細胞毒性測試，結果顯示濃度於10~20 ?g/mL對細胞有增生效果。另添加Ni之SBA-15與C750可誘導細胞死亡，且Ni-SBA-15統計上有顯著差異。氧化壓力(Reactive Oxygen Species，ROS)試驗暴露於C750與CNi750(添加Ni)狀況下皆無明顯ROS產生。
According to statistics compiled by the Taiwan Environmental Protection Administration (TEPA), organic solvents are the main constituent of waste solvent. Using organic solvents to synthesize materials will not only reduce the cost of pollutant control but also decrease the risk of pollution. In this study, pyrolytic chemical vapor deposition (CVD) was employed for the synthesis of carbon nanotubes via three carbon sources (acetylene, acetone, and toluene) at 650-950oC in nitrogen atmosphere. Santa Barbara Amorphous-15 (SBA-15) was selected as the template and Ni as the catalyst.
To understand the physicochemical properties of SBA-15 and carbon nanotubes, they were analyzed with scanning electron microscopy (SEM), transmission electron microscopy (TEM), surface area and pore size analyzer, inductively coupled plasma optical emission spectrometry (ICP-OES) and Raman spectrometry. The exhaust compositions including organic compounds, polyaromatic hydrocarbons (PAHs), volatile organic compounds (VOCs), CO, CO2, HCs and NOx in liquid and gas phases were analyzed by gas chromatography–mass spectrometry (GC-MS) and gas monitors. In addition, a cytotoxicity test was employed to determine the toxicity of SBA-15 and carbon nanotubes.
The BET surface area/pore size of SBA-15 and Ni-SBA-15 was 652 m2/g/41? and 477 m2/g/56?, respectively. They were classified as mesoporous materials and composed by small rod series into bundles and an orderly arranged hexagonal structure.
Carbon material was synthesized by acetylene and acetone at different temperatures (650, 750 and 850oC). The average pore diameter increased with the decrease of BET surface area and pore volume. The curly shape of the carbon nanotubes was formed by acetylene pyrolysis on Ni-SBA-15 at 650oC. Acetone accompanied by Ni-SBA-15 formed carbon nanotube at 650, 750 and 850oC. Toluene pyrolyzed to form carbon nanotube on Ni-SBA-15 at 850 and 950oC.
In the gas phase, BETX (benzene, ethyltoluene, toluene, and xylene) were the main compositions of VOCs during solvent pyrolysis. Results indicate that the Ni catalyst could decrease VOC concentration. In addition, the main compositions of PAHs were naphthalene and pyrene, and acetylene produced higher PAH concentrations than acetone and toluene.
Results of the cytotoxicity test indicated that the A549 cell could enhance the growth of cell culture under the exposure of acetylene derived carbon materials at 10-20?g/ml. In addition, Ni-SBA-15 and C750 could induce apoptosis of cell culture. There was no significant reactive oxygen species (ROS) stress for A549 during the exposure of C750 and CNi750. |
