This progress report provides an overview on recent advances in bioapplications of carbon nanotubes including the chemical modification of carbon nanotubes, targeting specifically their covalent and noncovalent conjugations with a variety of biological and bioactive species (proteins and peptides, DNAs/RNAs, and carbohydrates). Furthermore, the significant recent development and progress in the use of carbon nanotubes for biosensors, drug and other delivery systems, bioimaging, etc. and in the understanding of in vivo biodistribution and toxicity of carbon nanotubes are reported.

A new synthesis method for the preparation of high-performance PtRu electrocatalysts on multiwalled carbon nanotubes (MWCNTs) is reported. In this method, bimetallic PtRu electrocatalysts are deposited onto 1-aminopyrene (1-AP)-functionalized MWCNTs by a microwave-assisted polyol process. The noncovalent functionalization of MWCNTs by 1-AP is simple and can be carried out at room temperature without the use of expensive chemicals or corrosive acids, thus preserving the integrity and the electronic structure of MWCNTs. PtRu electrocatalysts on 1-AP-functionalized MWCNTs show much better distribution with no formation of aggregates, higher electrochemically active surface area, and higher electrocatalytic activity for the electrooxidation of methanol in direct methanol fuel cells as compared to that on conventional acid-treated MWCNTs and carbon black supported PtRu electrocatalysts. PtRu electrocatalysts on 1-AP-functionalized MWCNTs also show significantly enhanced stability.

Abstract:To develop functional sustainable epoxy resins, we report a novel epoxy resin (DEU-EP) with high net biobased content (70.2 wt%) derived from renewable eugenol. We comparatively study DEU-EP with a commercial bisphenol A epoxy resin (DGEBA) in the presence of a most representative aromatic diamine curing agent, 4,4'-diaminodiphenyl methane (DDM).Differential scanning calorimetry reveals that DEU-EP can be sufficiently cured by DDM at a slower rate than DGEBA. By applying an autocatalytic reaction model, we adequately simulate the curing rate of DEU-EP/DDM, and reveal its detailed kinetic mechanisms from model-free isoconversional analysis. Dynamic mechanical analysis shows that DEU-EP/DDM takes higher storage modulus up to ~97 o C than DGEBA/DDM with the glass temperature of 114 o C. Nanoindentation and thermogravimetric analysis demonstrate that compared with DGEBA/DDM, DEU-EP/DDM exhibits a 20%, 6.7% and 111% increase in Young's modulus, hardness and char yield, respectively. Microscale combustion calorimetry data show that DEU-EP/DDM expresses 55% and 38% lower heat release rate and total heat release than DGEBA/DDM, respectively.Macroscopically, the horizontal burning test approves DEU-EP/DDM can self-extinguish in a short time. Our results demonstrate that the eugenol building blocks and their arrangement greatly affect the cure behaviors of DEU-EP/DDM, and contribute significantly to its enhanced mechanical properties, high-temperature charring ability and chain motions at glass state, as well as the reduced flammability. To summarize, DEU-EP exhibits a high promise as a new sustainable epoxy monomer for fabricating high biobased content, high rigid and low flammable epoxy materials.

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Novel azido-functionalized POSS were synthesized, which could serve as nanoprecursors for higher-order molecular construction of organic-inorganic hybrids via"click" chemistry.

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Pt and Au nanoparticles with controlled Pt : Au molar ratios and PtAu nanoparticle loadings were successfully self-assembled onto poly(diallyldimethylammonium chloride) (PDDA)-functionalized graphene (PDDA-G) as highly effective electrocatalysts for formic acid oxidation in direct formic acid fuel cells (DFAFCs). The simultaneously assembled Pt and Au nanoparticles on PDDA-G showed superb electrocatalytic activity for HCOOH oxidation, and the current density associated with the preferred dehydrogenation pathway for the direct formation of CO(2) through HCOOH oxidation on a Pt(1)Au(8)/PDDA-G (i.e., a Pt : Au ratio of 1 : 8) is 32 times higher than on monometallic Pt/PDDA-G. The main function of the Au in the mixed Pt and Au nanoparticles on PDDA-G is to facilitate the first electron transfer from HCOOH to HCOO(ads) and the effective spillover of HCOO(ads) from Au to Pt nanoparticles, where HCOO(ads) is further oxidized to CO(2). The Pt : Au molar ratio and PtAu nanoparticle loading on PDDA-G supports are the two critical factors to achieve excellent electrocatalytic activity of PtAu/PDDA-G catalysts for the HCOOH oxidation reactions.