光聲法應用於偵測木質材料釋出之甲醛研究

The Detection of Formaldehyde Emission in Wood Based Materials by Using a Photoacoustic

龍暐(Way Long)

指導教授 ： 藍浩繁

國立屏東科技大學/農學院/熱帶農業暨國際合作系所/博士(2008年)

https://doi.org/10.6346/NPUST.2008.00036

摘要

多數人在其一生中有將近90%以上的時間是在室內環境內度過，因此，室內空氣品質對人健康是重要的影響因子。近年來建材所釋出之揮發性有機物質(Volatile organic compounds- VOCs)對室內人員之健康危害等議題，在許多國家及研究單位已對室內用建築材料的VOCs釋出控制與分析監測進行研究。本研究的目的在發展光聲法(Photoacoustic-PA)可應用於室內空氣污染監控領域、非破壞檢測、環境和材料科學領域。
光聲法結合可調頻率之光參數振盪雷射(Optical parametric oscillator laser -OPO)，量測頻率範圍2800 cm-1~ 2806 cm-1、開放式光聲感測器、小型環境控及資料擷取器，且在一般常壓環境下(1 atm、溫度22 oC+ 2 oC、相對溼度60%+ 5%)進行定性與定量分析量測。研究結果甲醛之特徵頻譜2805 cm-1不會受水氣影響，可做為甲醛之定性、定量分析。
根據光聲法實驗其系統具有極高的靈感度為6.210 9 Wcm-1(Hz) 1/2，較密閉式光聲量測感度值高2 倍，並且能夠連續地監測微量甲醛氣體濃度隨時間的變化。此系統量測極限可達到億分之一(ppbV)，實驗結果量測得0.8ppbV濃度的甲醛。
單板層積材(LVL)、中密度纖維板(MDF)兩種試材做為建材甲醛釋出研究。光聲法即時量測測試樣品於甲醛釋出過程中在環控箱內甲醛的濃度變化，並應用一階逸散模型(First order model)評估實驗值(其線性回歸R2 為0.99)。即時監測環控箱內甲醛濃度的變化，連續量測記錄甲醛濃度，透過釋出時間與濃度之趨勢曲線，更清楚瞭解木質材料在一般環境下甲醛釋出行為。並建立一個快速且簡易的建材甲醛釋出與吸附甲醛偵測的工具。利用此光聲法可推估不同木質建材之釋出影響與竹炭之甲醛吸附量與分類，進一步可作為室內設計與室內空氣品質管理之依據。

關鍵字

揮發性有機物 ； 光聲法 ； 木質材料 ； 吸附

並列摘要

The indoor air quality is important to human health and comfort since most people spend 90% of their time indoors. In recent years, the awareness of serious volatile organic compounds (VOCs) problems, by both researchers and the governments, have prompted active studies of indoor environments. VOCs constitute an important class of indoor air contaminants. Building materials which have been developed mainly from the viewpoint of construction and energy conservation, have been acknowledged as major VOCs emission sources indoors. Therefore, understanding of the emissions from indoor sources requires knowledge of the accurate qualitative and quantitative monitoring detection technic. This study has been developed the photoacoustic (PA) in the field of atmospheric pollution monitoring, the nondestructive application, environmental applications and material science applications.
The photoacoustic combines the parameter of adjustable light of frequency to an optical parametric oscillator laser (OPO) 2800 cm-1~ 2806 cm-1, multipass acoustically open photoacoustic detector (MOPAD), a modify small desiccator chamber, and data acquisition system in ambient environment (1 atm, temperature 22oC+ 2oC, relative humidity 60%+ 5%). The central idea and objective of this study aim at the development of photoacoustic system which could lead to monitor VOCs-formaldehyde without water interference.
The sensitivity of the photoacoustic is a significant effect that the application requires detection limits down to ppb levels and simultaneity response. The use of desiccator chamber with MOPAD made formaldehyde detection at concentration of 0.8ppbV possible. Formaldehyde monitoring with typical ambient concentration of water vapour at atmospheric pressure could be successfully achieved using an innovative approach.
An integrated procedure with diagnosis evaluation can predict simulation for wood based materials. The PA obtains negligible interference of water absorption which is at 2805cm-1 of formaldehyde spectrum. The results consisted of comparing the fit of formaldehyde emissions over time with a first order model. The correlation of the data to the linear model is good with an overall average R2 of 0.99 for the wood based material samples.
The photoacoustic strategic was estabilished to be adopted in different treatment process. This strategic included both formaldehyde emissions of the wood based materials prerequisite procedure and its adsorption of the bamboo charcoals prerequisite procedure, which was utiltized by designers or indoor air managers.

並列關鍵字

volatile organic compounds ； photoacoustic ； wood based material ； adsorption

參考文獻

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