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• High-pressure pyrolysis behaviors of three C5 cyclic hydrocarbons were investigated. • A universal kinetic model for three C5 cyclic fuels was proposed and validated. • Differences among three fuels specific decomposition pathways were evaluated. • Effects of unsaturation on intrinsic reactivity and PAH formation were revealed. To further explore the decomposition behaviors of C5 cyclic hydrocarbons, important components in the transportation fuels and pivotal intermediates in high-density liquid fuels, the pyrolysis of cyclopentane, cyclopentene and cyclopentadiene with different unsaturation degrees were investigated. The experiments of cyclopentane and cyclopentene were performed at 1.0, 30.0 atm and 773–1173 K in a flow tube reactor. The mole fraction profiles of pyrolysis species, involving C1-C5 small hydrocarbons and monocyclic, bicyclic as well as polycyclic aromatic hydrocarbons (MAHs, BAHs and PAHs), were provided. A universal kinetic model for three C5 cyclic fuels pyrolysis chemistry was proposed and reasonably predicted the speciation profiles newly reported in this work and literature, where rate coefficients of the crucial reactions were compared and upgraded. The differences among three fuels specific pathways were evaluated and the effects of unsaturation on the pyrolysis characteristics of intrinsic reactivity and aromatics formation were revealed. Cyclopentene has the highest pyrolysis reactivity, followed by cyclopentane and cyclopentadiene. Simultaneously formed fuel radicals and key intermediates in three C5 cyclic fuels influence the formation channels of small products, MAHs and BAHs. The saturated cyclopentane is easily occur the ring-opening reaction to generate more C2 and C3 species, whereas the increase in unsaturation promotes MAHs and BAHs formation in cyclopentene and cyclopentadiene pyrolysis, especially the toluene, styrene, indene and naphthalene. The rate of production analysis shows the formations of these MAHs and BAHs are strongly dependent on the concentration levels of cyclopentadienyl resonance stabilized radical (RSR). Differently, the dominated growth pathways of three- and four-ring PAHs are barely influenced by the specific fuel chemistry and indenyl plays a crucial role via the typical RSR chain reactions at high pressures. [ABSTRACT FROM AUTHOR]

• ZIF-8 MOFs were used to load high amount of antibiotics (LEVO) showing pH responsiveness to bacterial infection. • The negatively charged ZIF-8@LEVO@HA nano drug carrier was combined onto CL after amination treatment. • The antibacterial CL has a high drug loading capacity (0.65 mg/cm2) owing to the surface bound ZIF-8. • The ZLHP-CL showed excellent bactericidal effect with inhibitory zone diameter 34 mm. • In infectious keratitis animal, ZLHP-CL efficiently killed bacteria, reduced the inflammation reaction in corneal tissue repair. Eye trauma, ophthalmic surgery and contact lens (CL) wearing cause corneal infection and bacterial biofilms formation, which further lead to corneal ulcer and perforation. In view of the low bioavailability of antibiotic eye drops and the clinical problems that cause bacterial resistance, we used pH sensitive zeolitic imidazolate framework-8 metal–organic frameworks (ZIF-8 MOFs) to load broad-spectrum antibacterial drugs levofloxacin (LEVO). After the surface modification by hyaluronic acid (HA), the nanomaterial surface was negatively charged. A simple amination treatment was used to endow CL surface with amino groups to combine the negatively charged nano drug loading system through electrostatic forces. The bacteriostatic ring of ZIF-8@LEVO@HA-PEI modified CL (ZLHP-CL) was 34 mm, which could be owing to the high drug loading capacity of ZIF-8 (0.65 mg/cm2). The bactericidal function was further confirmed by shake flask method and live/dead bacterial staining assay against S. aureus , S. epidermidis and E. coli. It is worth mentioning that ZLHP-CL showed significant pH sensitivity to the bacterial infection, which released drug rapidly at pH 5.5 and hardly released drug at pH 7.4. In the bacterial biofilm's formation experiment, it was found that ZLHP-CL obviously inhibited bacterial adhesion and biofilms formation. Furthermore, it was proved in infectious keratitis animal that ZLHP-CL could kill the bacteria and reduce the inflammation reaction, which showed advantages in corneal tissue repair and light transmittance maintenance. In this work, based on nanotechnology, a facile CL drug loading technology is developed, which can be used to sustained release of various drugs for ophthalmic diseases treatment. [ABSTRACT FROM AUTHOR]