石英晶體振盪器一般常用於電子線路中產生固定之頻率,當石英晶體膜表
面因吸附化合物而使負載之重量增加時,其振盪頻率隨之遞減。在本研究
中,利用石英晶體振盪器石英膜表面吸附化合物之頻率改變特性,先建立一
套由個人電腦(IBM PC-AT或其他相容機種)經8255界面作多頻道感測器之
選擇控制系統,同時以8253計數器直接抓取並儲存頻率變化訊號之系統,並
且研究在石英晶片表面上塗佈具有選擇性吸附能力之單苯15冠5(
Benzo-15-crown-5)薄膜時對各類毒性高揮發之有機物氣體之選擇性吸附
。在本研究中亦針對石英晶體振盪器之各種實驗參數進行探討,如石英振
盪基本頻率及不同表面負載量對感測器的靈敏度所造成之影響。而在選擇
性方面除了研究單苯15冠5薄膜對醇類、胺、酸、鹵烷、酮等各類不同官
能基之選擇性,同時亦研究同類有機分子中,不同的結構、碳鏈大小所造成
之訊號強度之不同。最後並以大環胺醚(Cryptand 22)塗佈於石英表面所
造成之不同選擇行為與單苯15冠5互作比較,研究冠狀醚環上為氧原子或氮
原子所表現之不同效果。

Quartz crystal oscillator has been used for constant frequency
source in electric circuit.The frequency of quartz crystal
oscillator decrease as the surface mass load increase.Firstly,
A home-made experimental computer interface system based on
personal computer (IBM PC-AT or compatible)was prepared.The
computer interface includes the selective multi-channel sensors
and Intel-8255 interface .Selective the frequency shift was
measured with Intel-8253 counter interface. Benzo-15-crown-5
quartz menbrane was applied as a sensor and showed selective
absorption for various organic molecules. Experiment parameters
such as the fundamental frequency and coating load to the
preformance of piezoelectric sensor had been also discussed.
Selectivity of B15C5 quartz menbrance sensor for alcohol,amine,
alkyl halide and ketone were investigated. Effect of different
steric structure and length of carbon chain with same funtional
group on the frequency change of the crown ether quartz sensor
were also studied.Besides B15C5,Cryptand 22 was also applied as
an adsorbent for Organic species.It showed that the nitrogen
atom instead of oxygen atom on the crown ether molecule will
lead to quite different selectivity for species.
Quartz crystal oscillator has been used for constant frequency