Hollow carbon nanostructures have inspired numerous interests in areas such as energy conversion/storage, biomedicine, catalysis, and adsorption. Unfortunately, their synthesis mainly relies on template-based routes, which include tedious operating procedures and showed inadequate capability to build complex architectures. Here, by looking into the inner structure of single polymeric nanospheres, we identified the complicated compositional chemistry underneath their uniform shape, and confirmed that nanoparticles themselves stand for an effective and versatile synthetic platform for functional hollow carbon architectures. Using the formation of 3-aminophenol/formaldehyde resin as an example, we were able to tune its growth kinetics by controlling the molecular/environmental variables, forming resin nanospheres with designated styles of inner constitutional inhomogeneity. We confirmed that this intraparticle difference could be well exploited to create a large variety of hollow carbon architectures with desirable structural characters for their applications; for example, high-capacity anode for potassium-ion battery has been demonstrated with the multishelled hollow carbon nanospheres.

Although textile-based triboelectric nanogenerators (TENGs) are highly promising because they scavenge energy from their working environment to sustainably power wearable/mobile electronics, the challenge of simultaneously possessing the qualities of cloth remains. In this work, we propose a strategy for TENG textiles as power cloths in which core-shell yarns with core conductive fibers as the electrode and artificial polymer fibers or natural fibrous materials tightly twined around core conductive fibers are applied as the building blocks. The resulting TENG textiles are comfortable, flexible, and fashionable, and their production processes are compatible with industrial, large-scale textile manufacturing. More importantly, the comfortable TENG textiles demonstrate excellent washability and tailorability and can be fully applied in further garment processing. TENG textiles worn under the arm or foot have also been demonstrated to scavenge various types of energy from human motion, such as patting, walking, and running. All of these merits of proposed TENG textiles for clothing uses suggest their great potentials for viable applications in wearable electronics or smart textiles in the near future.

Self-assembly of synthetic macromolecules, inspired by the organization of biomolecules in nature, is a powerful approach for fabricating novel nanostructures, whose potential applications in nanomedicine are of significant interest. 1,2 Using amphiphilic linear copolymers as building blocks, various supramolecular architectures have been constructed, whose compositions, sizes, and morphologies are all tunable. [3][4][5] In spite of that, those nanostructures, made from synthetic macromolecules, are still primitive compared with those from biomolecules, which exhibit high complexity developed by evolution for millions of years. Our interest to attain nanostructures with higher complexities, approaching those of biological systems, drives our design of more types and sizes of macromolecular and nanoscopic building blocks, extending beyond simple linear block copolymers.Our initial targets are hetero-grafted diblock molecular brushes, 6,7 in which two different types of polymeric side chains are grafted sequentially along a backbone. These structures are designed as nanoscopic molecular frameworks having defined three-dimensional shape and control over the entire compositional profile, to mimic some features of the globular shape and compositional heterogeneities of protein building blocks. Three strategies are often used to synthesize molecular brushes: "grafting from", 8-11 "grafting onto", 12,13 and "grafting through". 14-18 The first two strategies can afford molecular brushes with relatively long and well-defined backbones. In the synthesis of hetero-grafted diblock molecular brushes, [19][20][21][22] for which the block segments of differing compositions are distributed along the primary molecular brush backbone, the "grafting through" strategy has several conveniences and advantages in avoiding many side reactions and providing significant structural control 6 due to the use of presynthesized polymers that are then polymerized to afford the final brush structure. To polymerize the highly diluted chain end groups of the polymers that ultimately become the grafted side chains, ring-opening metathesis polymerization (ROMP) is often applied. 14,15 Herein, by exploiting the orthogonality and livingness of reversible addition-fragmentation chain transfer (RAFT) polymerization 23 and ROMP, 24-26 we have developed a facile and efficient "grafting through" strategy to synthesize hetero-grafted diblock molecular brushes with precisely controlled architecture. These structures were transformed into amphiphilic diblock molecular brushes, which were then investigated as nanoscopic building blocks for the assembly of supramolecular nanostructures in aqueous medium.The amphiphilic hetero-grafted diblock molecular brush was produced by a highly efficient, one-pot "grafting-through" process, involving the sequential ROMP of norbornenylterminated macromonomers, followed by a deprotection reaction (Scheme 1). R-Norbornenyl poly(tert-butyl acrylate) (NB-PtBA) (1) and R-norbornenyl polystyrene (NB-PS) (2) macromonomers were firs...

Polymer flooding characteristics of partially hydrolyzed polyacrylamide (HPAM) solution with the addition of NaOH were examined in homogeneous glass-bead packs. The heavy oil recovery in unconsolidated sandstone formations by applying the alkali-polymer flooding was observed. Experimental results showed that HPAM solution was sensitive to temperature, salinity, and alkali, finding that alkali-polymer solutions are more effective in improving viscosity than conventional polymer solutions. The solution of 0.5 wt % NaOH mixed with 1500 ppm HPAM (12 mol % hydrolysis degree) was found to be the optimal choice, which gives rise to the highest viscosity on the rheological characterization. Flood tests using the alkali-polymer solution showed an increase in oil recovery by 30% over water-flooding when the water-cut reached 95%, indicating that alkali-polymer could be more effective in improving sweep efficiency than polymer flood.

As the most straightforward synthetic strategy for cyclic polymers in theory, the traditional homodifunctional bimolecular ring-closure methods showed limited success for preparing pure cyclic polymers in practice even after several decades of development. A breakthrough was achieved in this paper to develop a successful homodifunctional bimolecular ring-closure method using a self-accelerating double strain-promoted azide− alkyne click reaction as the intermolecular and subsequent intramolecular coupling reactions. Because of the self-accelerating property of coupling reaction, this novel approach eliminated the usage of equimolar quantities between telechelic polymers and small molecule linkers, which was the prerequisite of traditional homodifunctional bimolecular ring-closure methods for pure cyclic polymers. More importantly, this approach could use an excess amount of small linkers to increase the intermolecular coupling reaction rate, further resulting in a significantly enhanced preparation efficiency of cyclic polymers.

Tobacco stalks are an abundant biomass resource which are otherwise treated as waste. In this work, the effect of hydrothermal carbonization temperature and time on the structures, chemical compositions and combustion characteristics of hydrochars obtained from tobacco stalks were evaluated. The carbon content, higher heating value, and energy yield increased with accompanying decrease in hydrogen and oxygen contents with the increase of treatment temperature and time. The evolution of the H/C and O/C atomic ratios indicated dehydration and devolatilization processes occurred during hydrothermal carbonization. The weight loss, combustion range and characteristic temperatures of tobacco stalks were significantly modified after hydrothermal carbonization, resulting in higher ignition temperatures and higher energy density. The kinetics model, Coats-Redfern method revealed the activation energy of hydrochars in zone 2 and 3 were among 43.7-74.8kJ/mol and 46.7-85.8kJ/mol, respectively. Our results show that hydrothermal carbonization reaction can facilitate transforming tobacco stalks into energy-rich solid fuel.

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Triblock copolymer brushes were functionalized with nucleic acid sequences, which allowed the polymers to connect head-to-tail and form supramolecular nanostructures. Two approaches were designed and implemented, using either a palindromic DNA attached to both ends of the polymer or two different DNA sequences attached regiospecifically. Given appropriate conditions, the DNA-brush conjugates self-assembled to form either nanoworms with length up to several microns or cross-linked networks. This process is analogous to the step-growth polymerization of small molecule monomers.