近幾年太陽能驅動的界面蒸發技術快速發展，該技術是一種低成本、環保、高效率的海水淡化技術。依靠低熱傳係數、具優異水傳輸效果的材料作為基材，將水輸送至表面的光熱材料進行界面加熱蒸發海水，以獲得淡化水。然而界面蒸發效率會受到鹽溶液濃度的影響，在本研究中比較了兩種水路系統(二維與一維)與兩種表面光熱材料(CNT與PVDF-CNT)，會造成蒸發效率、結晶鹽型態的不同。
本研究中使用矽藻土與高嶺土作為基材，因矽藻土無法單獨成型，利用高嶺土加水之後易於塑型的特點，與矽藻土以7：3比例結合，再經過900 ℃ 燒結後，高嶺土轉為強度較高的偏高嶺土以此穩定結構，形成多孔塊材。矽藻土/偏高嶺土多孔塊材熱傳導係數為0.201 W m-1K-1；在太陽光光譜範圍波長250 nm –2500 nm 檢測表面塗層CNT與PVDF-CNT後的吸光率，分別為95.92 %與93.59 %，具有高吸光率，並在紅外線熱顯像儀的觀察下，能夠快速聚集熱量，其中一維系統比二維系統具有更高的表面溫度，並且PVDF-CNT疏水表面比CNT表面具有更高的溫度。一倍太陽光(1 kW/m2h)下蒸發純水8小時僅能獲得3.755 Kg/m2，在矽藻土/偏高嶺土為基材的蒸發裝置幫助後，二維水路系統在3.5 % NaCl溶液下平均能夠提升4.1倍的蒸發量，而一維系統平均可以提升5.3倍；10 % NaCl溶液二維系統平均能夠提升3.8倍的蒸發量，一維系統平均可以提升4.2倍。海水淡化實驗中，阻鹽率可達到99.96 %，淡化水經離子層析儀檢測符合WHO與EPA飲用水標準，並且裝置在經過連續循環模擬仍然可以維持高蒸發量。矽藻土每公斤價格為0.12元，高嶺土為每公斤0.22元，因此低成本，易於大規模製造，能夠更輕易地開發出高效的太陽能蒸發裝置。

The interfacial solar-to-steam conversion (ISSC) system was developed quickly in recent years. The materials play an important role in the ISSC system. There are three key components making up a solar interfacial evaporation system, which are photothermal materials, heat management and water supply. Relying on the material with low heat transfer coefficient and excellent water transmission effect as the base material, the photothermal material that transports water to the surface heats and evaporates seawater at the interface to obtain desalinated water. However, the interface evaporation efficiency will be affected by the concentration of the salt solution. In this study, two water path way systems (two-dimensional and one-dimensional) and two surface photothermal materials (CNT and PVDF-CNT) are compared, which will cause the difference in the evaporation efficiency and crystalline salt.
In this study, we used celite and kaolin as substrates. Because celite can’t be formed by itself, and kaolin is easy to mold after adding water. We combined celite and kaolin in a ratio of 7：3. After sintering at 900 ℃, the kaolin is converted to metakaolin with higher strength to stabilize the structure and form a porous block material. The thermal conductivity coefficient of celite/metakaolin porous block material is 0.201 wm-1K-1. After coating CNT and PVDF-CNT on the surface, the absorbance is 95.92% and 93.59%, respectively. It has quickly accumulate heat observed in infrared thermal imaging camera. The 1D system has a higher surface temperature than the 2D system, and the PVDF-CNT surface has a higher temperature than CNT surface. Evaporating bulk water under 1 sun intensity for 8 hours can only obtain 3.755 Kg/m2. With the help of an evaporation device based on celite/metakaolin, the 2D system can increase and average if 4.1 times in 3.5% NaCl solution. The 1D system can increase the evaporation by an average of 5.3 times；The 2D system with a 10% NaCl solution can increase the evaporation by an average of 3.8 times, and the 1D system can increase the evaporation by an average of 4.2 times. In the seawater desalination experiment, the salt rejection rate can reach 99.96%. The desalinated water is tested by ion chromatography to meet the WHO and EPA drinking water standards, and the device can still maintain high evaporation after continuous circulation simulation. The price of celite is 0.12 NTD/Kg and kaolin is 0.22 NTD/Kg. Therefore, it is low-cost and easy to manufacture on a large scale. It’s easier to develop efficient solar evaporation devices. This study successfully fabricated celite/metakaolin porous block material which has great potential in interfacial solar-to-steam conversion system.

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