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Fiber-modified asphalt has excellent road performance, but the mechanism of this enhancement still requires deeper understanding. Herein, the interfacial interaction between fibers and asphalt is explored using an adsorption kinetic model with the adsorption of fibers on the four components of asphalt as a criterion. The proposed pseudo-first-order kinetic model and pseudo-second-order kinetic model were developed using aramid fibers (AF) and AF-polydopamine (PDA)-octadecylamine (ODA) (AF-PDA-ODA), which were prepared by grafting ODA onto AF with PDA and nacre fibers and molybdenum disulfide (MoS2). Fourier-transform infrared (FT-IR) spectroscopy analysis confirmed that the modified fibers exhibit physical and chemical cross-linking with the four components of asphalt, which facilitated the uniform distribution of fiber and effectively improved its compatibility with asphalt. This led to the formation of an excellent network structure that consequently boosted the rheological properties of the modified-fiber-incorporated asphalt. [ABSTRACT FROM AUTHOR]

[Display omitted] • ZIF-8 had the highest ACEI (CW) enrichment among five typical MOFs. • ZIF-8 had ultra-high selective adsorption for CW in simulated protein hydrolysate (α = 46.6). • ACE inhibitory activity increased 70.9 times after CW was desorbed by ZIF-8. • Interactions of MOFs and peptides are influenced by the electrostatic, CH/SH ··· π and molecular sizes. • ZIF-8 can achieve desorption of CW with a pH response in the range of 7.0–12.0. Searching adsorbents for high recognition and adsorption capacities of active peptides has become the hotspot of scientific research in the screening and purification of peptides. In this work, we selected MOFs materials with good biocompatibility to systematically investigated for the selective adsorption of highly active ACE inhibitory peptides. Herein, five typical kinds of metal organic frameworks (MOFs) were initially screened for their adsorption capacities towards di-peptide (CW) having ultra-high angiotensin-converting enzyme (ACE) inhibitory activity (IC 50 = 0.16 μM). The effects of their pore sizes and surface potentials on CW adsorption capacity were explored in this work. Among these MOFs, ZIF-8 was chosen as a di-peptide adsorbent due to its excellent adsorption capacity of CW (0.382 mmol/g). Besides, the adsorption behavior of ZIF-8 for di-peptides in the mixed solution was systematically explored. Experimental results indicated that ZIF-8 exhibited highly specific adsorption towards CW while showing very low and almost non-adsorption for the two inactive peptides, DD and RR. In their ternary peptide solution (molar ratio: CW/DD/RR = 1/10/10) for simulated protein hydrolysate, ZIF-8 displayed ultra-high adsorption selectivity (α = 46.6) for CW and thus enhanced almost 70.9 times the ACE inhibitory activity for the enriched solution. Meanwhile, molecular simulation revealed that ZIF-8 had high recognition towards CW, which was primarily attributed to synergistic mechanisms of electrostatic attraction, NH/SH ··· π interaction, and pore size screening of ZIF-8 towards CW. Interestingly, ZIF-8 was discovered for the first time to have a distinct pH-responsive property towards CW enrichment. Based on this property, pH-responsive adsorption was carried out with desorption over ZIF-8, and a stable regeneration process for 5 continuous adsorption/desorption cycles was accomplished. Collectively, this work proved that MOFs have promising application prospects in the field of peptide adsorption. [ABSTRACT FROM AUTHOR]

One-step adsorptive purification of methane (CH 4) from the multi-component mixtures containing CO 2 , acetylene (C 2 H 2) and ethane (C 2 H 6) is of great significance but challenging as distinct mechanisms are involved in the uptake of various gas molecules. Herein, a bismuth-based metal-organic framework (SU-100) bearing multi-affinity sites is applied for simultaneously sequestrating these impurities from CH 4. The intrinsic unsaturated Bi (III) sites endow SU-100 with specific recognition of CO 2 and C 2 H 2 via complexation with the open metal sites, while the dense distribution of carboxylate and biphenyl moieties in the nano-channels provides strong affinity for C 2 H 6 as well as additional affinity sites for C 2 H 2. Profiting from the exposed functional sites and suitable pore size, SU-100 exhibits decent ideal adsorbed solution theory (IAST) selectivity (CO 2 /CH 4 , C 2 H 2 /CH 4 and C 2 H 6 /CH 4) under ambient conditions. Moreover, the adsorption capacity remains unchanged for 10 consecutive cycles. The practical CH 4 purification performance is fully demonstrated by dynamic breakthroughs of various binary, ternary (CO 2 /C 2 H 2 /CH 4), and quaternary (CO 2 /C 2 H 2 /C 2 H 6 /CH 4) mixtures, in which more than 2.44 mol kg−1 of pure CH 4 can be produced from typical quaternary mixtures. Based on theoretical calculation and in-situ infrared analysis, synergistic effect of multiple interactions (π complexation, hydrogen bonding and CH−π interactions) accounts for simultaneous adsorption of multiple gases from CH 4. These results underpin highly selective capture of a range of gas mixtures that are relevant to one-step purification of natural gas. [Display omitted] • SU-100 bears multi-affinity sites in confined channel for gas accommodation. • Well-balanced sequestration of CO 2 , C 2 H 2 and C 2 H 6 from CH 4 was observed. • Pure CH 4 was produced in the breakthroughs of multi-component mixtures. • Co-adsorption of impurities over CH 4 is driven by synergic interactions. [ABSTRACT FROM AUTHOR]

[Display omitted] • 2D COFs delivered inverse 1-PE/AP selectivity in organic phase. • Structure-performance relationships of COFs analogues were unraveled. • TpBZ-COF with moderate pore space showed the best separation performance. • The adsorption mechanism was investigated experimentally and theoretically. Adsorption is considered as a promising method to purify the mixed acetophenone (AP) and 1-phenylethanol (1-PE) that are generally difficult to separate. Many efforts have been made to improve the preferential uptake of AP over 1-PE in aqueous phase, but there exists a practical bottleneck associated with their limited aqueous solubility. Herein, we demonstrate unprecedented reversal of selectivity in the organic medium enabled by β-ketoenamine-linked covalent organic frameworks (COFs), which were fabricated successfully by polycondensation between 1,3,5-triformylphloroglucinol (Tp) and diamines. The dependence of selective adsorption ability toward 1-PE on pore size was firstly investigated experimentally, indicating that TpBZ-COF with moderate pore size outperformed other analogues. The adsorption behaviors of 1-PE and AP onto TpBZ-COF were examined systematically. The evaluation results revealed a strong affinity toward 1-PE versus AP as well as excellent stability in recycling experiments. Further, the dynamic breakthrough experiments confirmed the practical application potential and remarkable recyclability. To probe the mechanism and structure–activity relationship, an imine-linked COF possessing similar porous structure was used as a reference for comparison of separation performance both experimentally and theoretically. The occurrence of hydrogen bonding between the hydroxyl of 1-PE and β-ketoenamine-linkage as H-bond acceptor in suitable pore spaces endows TpBZ-COF a fantastic candidate for purifying 1-PE and AP from petrochemical by-products. [ABSTRACT FROM AUTHOR]

[Display omitted] • CD@PTDIT was fabricated by in situ self-polymerization strategy. • The core–shell structure retains the cage-type stacking of β-CD. • CD@PTDIT-1 shows record-high AP/1-PE selectivity. • Efficient separation of AP and 1-PE was demonstrated in fixed bed column. Efficient separation of acetophenone (AP) and 1-phenylethanol (1-PE) is crucial but challenging for high-value utilization of petrochemical by-products. To boost the AP/1-PE separation performance, a core–shell structure consisting of polyisocyanate layer grown on β-cyclodextrin (β-CD) particles (CD@PTDIT) was successfully fabricated by in-situ self-polymerization of toluene-2,4-diisocyanate trimer (TDIT) onto β-CD surface. The unique micro-architecture and chemical compositions of CD@PTDIT were comprehensively investigated by X-ray diffraction (XRD), solid-state 13C CP/MAS NMR, X-ray photoelectron spectroscopy (XPS), elemental analysis, etc. Results indicated the well-maintained crystallinity of β-CD backbone and tunable thickness of polyisocyanate shell were integrated in CD@PTDIT. The unprecedented selectivity of CD@PTDIT for AP over 1-PE (6.9–9.4) combined with high AP uptake as well as the excellent recyclability was confirmed by both static adsorption and dynamic breakthrough experiments. Multicomponent breakthrough experiments using petrochemical by-product further demonstrated that CD@PTDIT maintained this selectivity in the practical applications. In-depth mechanism study using theoretical and structural investigations defined the essential host–guest interactions that produce the observed separation performance. [ABSTRACT FROM AUTHOR]