Solid-state NMR methods were used to characterize the heterogeneous dynamics, miscibility, and microdomain structure in nanostructured thermoset blends of epoxy resin (ER) and amphiphilic poly(ethylene oxide)-block-poly(propylene oxide)-block-poly(ethylene oxide) triblock copolymers (PEO-PPO-PEO). NMR experiments show that there is a distinct dynamic difference between the block copolymer (both PEO and PPO) and cured-ER matrix indicating the presence of phase separation, which also confirms the existence of the interphase region including a considerable amount of immobilized PEO and mobilized partially cured ER. An improved method based on spin-diffusion experiments enabled a quantitative determination of the interphase thickness. It is shown that a large percentage of PEO were intimately mixed with ER in the interphase region of the blends, while the rest mobile PEO and all PPO segregated from the ER network. It is observed that the domain size and long period depend strongly on the PEO fraction in the copolymers, whereas the interphase thickness of the blends is not sensitive to the PEO fraction. These NMR results unambiguously demonstrated that PEO blocks were only partially miscible with cured-ER network. Upon curing, the cross-linked rigid ER formed a separated microphase, while some PEO were locally expelled out of the cured-ER network and forms another microphase with PPO. The residual immobilized PEO were intimately mixed with some partially cured-ER matrix and formed the interphase region.

By adjusting the solution pH value below the isoelectric point (pI) of silk fibroin (SF) protein, the SF was in the cation state and it could interact strongly with unmodified anionic montmorillonite (MMT) surface. In this way, novel SF-MMT nanocomposites with good clay dispersion were successfully obtained, which were confirmed by X-ray diffraction and transmission electron microscopy. Further 1H CRAMPS and 13C CP/MAS NMR experimental results revealed that beta-sheet content of SF was remarkably enhanced for nanocomposite prepared below the pI of SF (SF-MMTA) due to the strong interaction between MMT and SF. In SF-MMTA nanocomposite, clay layers acting as an efficient nucleator could efficiently enhance the beta-sheet crystallization. On the contrary, SF preserved the native random coil conformation in SF-MMTN nanocomposites due to the weak interaction between MMT and SF. A tentative model was suggested and used to explain the mechanism of clay dispersion and conformational transition of silk protein.

Carbon dioxide capture and conversion have attracted extreme enthusiasm from the scientific community owing to global warming and environmental problems. However, conversion of CO under atmospheric pressure is of great challenge because of the inertness of CO. Herein, we present a novel covalent triazine framework (CTF-DCE) prepared via ZnCl-catalyzed ionothermal trimerization reaction of di(4-cyanophenyl)ethyne, which displays a high Brunauer-Emmett-Teller surface area of 1355 m g and an excellent CO capture capacity of 191 mg/g at 273 K/1 bar. More importantly, silver species can be successfully fixed on the CTF matrix to produce a stable CTF-DCE-Ag heterogeneous catalyst for outstanding catalysis in the terminal alkyne carboxylation reactions under atmospheric pressure. CTF-DCE-Ag exhibited over sixfold higher turnover numbers than Ag@MIL-101. The recyclability test of the CTF-DCE-Ag catalyst demonstrated a great potential application in various environmental and energy-related applications.

An azo-linked porous organic framework (Azo-Trip) in which triptycene is incorporated as linkage, has been constructed via a facile Zn-induced reductive homocoulping reaction. The Azo-Trip exhibits selective carbon dioxide uptake and excellent iodine uptake in vapour and liquid phase.

A new heptazine-based polymer network (Cy-pip) with highly rich nitrogen sites has been synthesized via catalyst-free direct coupling of cyameluric chloride (Cy) and piperazine (Pip). Cy-pip exhibits large CO2 uptake capacity (103.4 mg/g, 9.4 wt %, 1 bar/273 K) with high selectivity (117) toward CO2 over N2. Furthermore, this framework with high Lewis basic nitrogen sites has also been exploited as heterogeneous catalyst for Knoevenagel reaction of aromatic and heterocyclic aldehydes with active methylene compounds. Moreover, the catalyst can recycle up to four times with only a minor loss of activity.