微孔吸附劑在化學(xué)存儲領(lǐng)域獲得潛在應(yīng)用

化學(xué)分離在化學(xué)過程工業(yè)中的幾乎每個方面都不可忽視。據(jù)估計，全球能源消耗的10％至15％來自分離過程。應(yīng)對這一挑戰(zhàn)的一種途徑是取代傳統(tǒng)的能源密集型工業(yè)流程，這為新興的基于低能吸附技術(shù)提供了機會。例如以微孔吸附材料驅(qū)動的較低能量分離的蒸餾。

除了滿足分離應(yīng)用之外，微孔吸附劑還可在其他領(lǐng)域獲得潛在應(yīng)用，如化學(xué)存儲或催化。為實現(xiàn)這些廣泛的應(yīng)用，人們已開發(fā)了各種微孔吸附材料，如金屬有機骨架、共價有機骨架和沸石家族。所有這些家族的共同特征是：可基于化學(xué)修飾或組成成分的系統(tǒng)組合，來設(shè)計成千上萬的結(jié)構(gòu)。但是，對這些結(jié)構(gòu)逐一進行大量的實驗合成幾乎是不切實際的，特別是材料合成過程極為復(fù)雜的情況下。通過高通量分子模擬篩選是解決這一挑戰(zhàn)的有效過程。

來自美國佛羅里達大學(xué)的Coray M. Colina教授領(lǐng)導(dǎo)的小組，通過高通量分子模擬為吸附劑多樣性、吸附過程多樣性與聚合物重組、微孔聚合物吸附量之間的函數(shù)關(guān)系提供了深入的理解。同時作者報告了具有多種吸附物種的微孔聚合物及其吸附和結(jié)構(gòu)特性的分子模擬數(shù)據(jù)，該數(shù)據(jù)包含了345種不同吸附等溫線及240，000多種新發(fā)現(xiàn)的膨脹結(jié)構(gòu)。

該文近期發(fā)表于npj Computational Materials 7： 53 （2021），英文標題與摘要如下。

The enormous number of combinations of adsorbing molecules and porous materials that exist is known as adsorption space. The adsorption space for microporous polymers has not yet been systematically explored， especially when compared with efforts for crystalline adsorbents.

We report molecular simulation data for the adsorptive and structural properties of polymers of intrinsic microporosity with a diverse set of adsorbate species with 345 distinct adsorption isotherms and over 240，000 fresh and swollen structures.

These structures and isotherms were obtained using a sorption-relaxation technique that accounts for the critical role of flexibility of the polymeric adsorbents. This enables us to introduce a set of correlations that can estimate adsorbent swelling and fractional free volume dilation as a function of adsorbate uptake based on readily characterized properties.

The separation selectivity of the 276 distinct binary molecular pairs in our data is reported and high-performing adsorbent systems are identified.

編輯：jq