Three-dimensional and morphology-tunable superstructures were produced by engineering the interactions among functional groups in organic thin films, adsorbed precursors and the formed metal nanoparticles. The type and amount of functional groups take a leading role over controlling the superstructure shape. This approach is general and promising for fabricating various metal superstructures.

•PE21F was chosen to study the impact of substituent on epitaxial crystallization.•Kebab-like and rod-like thinner crystals formed on CNT and RGO, respectively.•Crystallizable sequence length and crystal structure of PE21F remained unchanged.•SC CO2 can accelerate the lateral growth of lamellae formed on nanofillers.Crystallization of well-defined precision polyethylene with fluorine substituent on every 21st backbone carbon (PE21F) induced by low-dimensional carbonaceous nanofillers (carbon nanotube (CNT) and reduced graphene oxide (RGO)) via solution crystallization and supercritical CO2 assisted solution crystallization were investigated. Transmission electron microscopy was used to investigate the morphology of carbonaceous nanofiller-induced PE21F crystals. The kebab-like and rod-like crystals formed on the CNT and RGO, respectively. Selected area electron diffraction (SAED) pattern revealed that the c-axis of polymer chain is parallel to the surface of the RGO. Differential scanning calorimetry (DSC) revealed the melting temperatures (Tm) of PE21F lamellae nanocomposites increased with crystallization temperature increasing. The X-ray diffraction (XRD) results showed that the incorporation of nanofillers did not influence the crystal structure of PE21F. The chemical composition of the PE21F nanocomposites measured by X-ray photoelectron spectra (XPS) confirmed substituent F as a defect of chain was accommodated into the crystal lattice.

•Ethylene-co-aryl ether polymers have been successfully synthesized via ADMET.•Crystalline polymers exhibit a sequence of melting/crystallization phenomenon.•Reducing the density of aryl ether units could alter the crystallization behavior.•Incorporation of aryl ether units has improved the thermal stability of polymers.A new family of polyolefins containing various aryl ether units have been designed and synthesized, and their thermal properties were studied. We prepared six acyclic diene monomers di(undec-10-enyloxy)aryl ether by a two-step approach and the corresponding homopolymers and copolymers with 1,9-decadiene by ADMET. Subsequent hydrogenation gave the corresponding ethylene-co-aryl ether polymers. The structures of these polymers were confirmed by 1H NMR, 13C NMR and FT-IR. Additionally, crystallization behaviors and thermal properties were investigated by differential scanning calorimetry (DSC), X-ray diffraction and thermal gravimetric analysis (TGA). The results show that incorporation of these aryl ether units has improved the thermal stability of polymers. And these polymers show a tendency of semicrystallinity to amorphous state with the insertion of more rigid phenyl rings in functional sites of polymers' main chain. Interestingly, DSC analysis reveals that a sequence of melting/crystallization phenomenon occurs in the crystalline saturated homopolymers.

Construction of superstructures with controllable morphologies from NPs is of great scientific and technological importance. A one-step method for simultaneous synthesis and assembly of Ag NPs to three-dimensional (3D) nanoporous superstructures is demonstrated. By varying the adsorption time of Ag precursors, an array of well-defined Ag superstructures with different morphologies are harvested. A “hot spot”-rich substrate for surface-enhanced Raman spectroscopy is established, which exhibits high sensitivity in trace detection of molecules. It is believed that the presented 3D nanoporous Ag superstructures hold great potential for various uses, such as novel multifunctional sensing and monitoring chips or devices.Keywords: polymer brushes; self-assembly; SERS; superstructures; three-dimension; tunable morphology

The present paper deals with the crack growth behavior of vulcanized natural rubber under fatigue loading. Our research focuses on the crack tip morphology evolution and its relationship with the crack growth rate. For this purpose, an original real-time monitoring method is applied to capture the crack tip morphology during standard fatigue testing. This method involves the use of a high speed microscopic camera and a dynamic mechanical analyzer with a crack growth testing unit. The tear energy (T) dependence of the crack tip morphology is discussed. It is revealed that there are two characteristic cracking morphologies: at T < 600 J m−2, the power law slope of dc/dn versus T is 6. Surface buckling and peeling at the crack-front surface occur, which result in the appearance of secondary cracks; at T > 600 J m−2, the power law slope of dc/dn versus T is 2. A ligament break-up mechanism dominates. This work gives us new opportunities to study the crack growth mechanism of rubbers from the viewpoint of real-time crack tip morphology investigation.

[3-t-Bu-2-O-C6H3CHN(C6F5)]2TiCl2 catalyst (FI catalyst) was immobilized on disilanolisobutyl POSS to synthesize disentangled ultra-high molecular weight polyethylene (UHMWPE)/POSS nanocomposites during ethylene in situ polymerization. The presence of POSS significantly influenced the polymerization properties of the FI catalyst active centers. It was shown that the characteristic of “living” polymerization of the FI catalyst was retarded. Furthermore, disilanolisobutyl POSS is dispersed uniformly in the UHMWPE matrix with particles size of only several tens nanometers. Interestingly, the incorporation of the POSS into nascent UHMWPE matrix led to a strong interaction between the POSS particles and the UHMWPE chains, resulting in an increased density of entangled chains, as reflected by rheological test. Moreover, the crystallinity and the lamellae thickness of nascent UHMWPE increased upon increasing POSS loading, as observed by differential scanning calorimetry. It suggested that the POSS particles would be presented as a nucleating agent. Finally, the thermal stability and the hydrophilic property of the nanocomposites were improved due to the incorporation of POSS particles.

Real time synchrotron wide angle and small angle X-ray scattering (WAXS and SAXS, respectively) were used to characterize the stretch induced structural evolution of α trans-1,4-polyisoprene (trans-PI). 2D WAXS results indicated two ensembles of crystalline modifications with distinctive orientation modes coexisted during stretching. Stretching transformed part of the monoclinic α phase into highly oriented orthorhombic β phase at strain ε = ~0.4. The β phase had rather high orientational degree with polymer chains parallel to the stretching direction, while the orientational degree of α phase was much lower. Complemented by qualitative 2D SAXS analysis, it was found that amorphous layer deformation and intralamellar chain slip dominated at different stretching stage. The melt and recrystallization process of α phase which led to the formation of β phase was also investigated. Formation of two interpenetrating networks of crystalline skeleton (constructed by residual α and β crystals) and amorphous entanglement accounted for the stress-hardening in the late stage.