This paper reports a new macromolecular design that incorporates hierarchical triptycene unit into thermally rearranged polybenzoxazole (TR-PBO) structures for highly selective and permeable gas separation membranes with great potential for H 2 purification and CO 2 removal from natural gas. We demonstrate that triptycene moieties not only effectively disrupt chain packing enabling microporous structure for fast mass transport, but also introduce ultrafine microporosity via the unique internal free volume intrinsic to triptycene unit that allows for superior molecular sieving capability in resulting PBO membranes. Consequently, these triptycene-based polybenzoxazole (TPBO) membranes display among the highest gas selectivities for H 2 separations (i.e., α(H 2 /N 2 ) = 96; α(H 2 /CH 4 ) = 203) and CO 2 removal from natural gas (i.e., α(CO 2 /CH 4 ) = 68) among existing glassy polymeric membranes. It is also demonstrated that microporous structure and gas transport properties of TPBO films are highly tailorable by adjusting the triptycene content and the ortho-functionality of the precursors. The highly diverse tunability, along with the excellent resistance toward membrane plasticization and physical aging, render the TPBO membranes with extremely versatile separation capability applicable for a wide range of important industrial processes to get clean or low carbon fuels and reduce carbon footprint.

Cell refractive index, an intrinsic optical parameter, is closely correlated with the intracellular mass and concentration. By combining optical phase-shifting interferometry (PSI) and atomic force microscope (AFM) imaging, we constructed a label free, non-invasive and quantitative refractive index of single cell measurement system, in which the accurate phase map of single cell was retrieved with PSI technique and the cell morphology with nanoscale resolution was achieved with AFM imaging. Based on the proposed AFM/PSI system, we achieved quantitative refractive index distributions of single red blood cell and Jurkat cell, respectively. Further, the quantitative change of refractive index distribution during Daunorubicin (DNR)-induced Jurkat cell apoptosis was presented, and then the content changes of intracellular biochemical components were achieved. Importantly, these results were consistent with Raman spectral analysis, indicating that the proposed PSI/AFM based refractive index system is likely to become a useful tool for intracellular biochemical components analysis measurement, and this will facilitate its application for revealing cell structure and pathological state from a new perspective.

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Rigid H-shaped pentiptycene units, with an intrinsic hierarchical structure, were employed to fabricate a highly microporous organic polymer sorbent via Friedel-Crafts reaction/polymerization. The obtained microporous polymer exhibits good thermal stability, a high Brunauer-Emmett-Teller surface area of 1604 m g, outstanding CO, H, and CH storage capacities, as well as good adsorption selectivities for the separation of CO/N and CO/CH gas pairs. The CO uptake values reached as high as 5.00 mmol g (1.0 bar and 273 K), which, along with high adsorption selectivity values (e.g., 47.1 for CO/N), make the pentiptycene-based microporous organic polymer (PMOP) a promising sorbent material for carbon capture from flue gas and natural gas purification. Moreover, the PMOP material displayed superior absorption capacities for organic solvents and dyes. For example, the maximum adsorption capacities for methylene blue and Congo red were 394 and 932 mg g, respectively, promoting the potential of the PMOP as an excellent sorbent for environmental remediation and water treatment.

Two new triptycene-based polyimides, 6FDA-1,4-trip_ortho and 6FDA-2,6-trip_para, were synthesized to investigate the effect of varying polymer backbone geometry on chain packing and gas transport properties. Changing the imide linkage geometry from para to ortho reduced gas permeabilities by ∼48% due to more efficient chain packing of the asymmetric ortho structure, which is demonstrated by decreased d-spacing and fractional free volume. Varying the triptycene orientation from the 1,4-to 2,6-connection also caused a decrease in permeability (e.g., 29% decrease for P CO2 ). This is likely the result of reduced chain mobility, as evidenced by increased T g , and a shift in free volume distribution toward smaller cavities, as supported by smaller d-spacing. Physical aging studies show that the equilibrium specific volume of these isomeric polymers is similar, as evidenced by nearly identical gas transport properties exhibited by all aged samples.