Resin Nanotubes Research Articles

Handedness Inversion of Chiral 3‐Aminophenol Formaldehyde Resin Nanotubes Mediated by Metal Coordination

AbstractPrecise adjustment of microstructure and handedness of chiral nanomaterials is important to regulate their properties and performance. Herein, helical 3‐aminophenol formaldehyde resin (APF) nanotubes and corresponding carbonaceous nanotubes with controllable handedness and optical activity were obtained via an external metal ion‐mediated supramolecular co‐templating method in an enantiomerically pure template system, in which an appropriate amount of Mn2+ (Co2+ or Ni2+) with moderate coordination abilities can reverse the spatial arrangement of the phenylglycine‐based amphiphilic template molecules through metal coordination. Different stacking modes of coordination complexes in disparate metal ion systems lead to diverse helical senses (diameter and pitch) of the obtained helical APF. In addition, this coordination mode of metal intervention can be applied to other amine‐based helical polymer synthesis systems, which paves the way for the design of high‐quality chiral nanomaterials with satisfactory physical parameters and properties.

Handedness Inversion of Chiral 3-Aminophenol Formaldehyde Resin Nanotubes Mediated by Metal Coordination.

Precise adjustment of microstructure and handedness of chiral nanomaterials is important to regulate their properties and performance. Herein, helical 3-aminophenol formaldehyde resin (APF) nanotubes and corresponding carbonaceous nanotubes with controllable handedness and optical activity were obtained via an external metal ion-mediated supramolecular co-templating method in an enantiomerically pure template system, in which an appropriate amount of Mn2+ (Co2+ or Ni2+ ) with moderate coordination abilities can reverse the spatial arrangement of the phenylglycine-based amphiphilic template molecules through metal coordination. Different stacking modes of coordination complexes in disparate metal ion systems lead to diverse helical senses (diameter and pitch) of the obtained helical APF. In addition, this coordination mode of metal intervention can be applied to other amine-based helical polymer synthesis systems, which paves the way for the design of high-quality chiral nanomaterials with satisfactory physical parameters and properties.

Left-handed helical polymer resin nanotubes prepared by using N-palmitoyl glucosamine.

Although the preparation of single-handed helical inorganic and hybrid organic-inorganic nanotubes is well developed, approaches to the formation of single-handed organopolymeric nanotubes are limited. Here, left-handed helical m-phenylenediamine-formaldehyde resin and 3-aminophenol-formaldehyde resin nanotubes were prepared by using N-palmitoyl glucosamine that can self-assemble into left-handed twisted nanoribbons in a mixture of methanol and water. In the reaction mixture, the helical pitch of the nanoribbons decreased with increasing reaction time. The resin nanotubes were obtained after removing the N-palmitoyl glucosamine template, and circular dichroism spectroscopy indicated that the organopolymeric nanotubes had optical activity. Carbonaceous nanotubes were then prepared by carbonization of the 3-aminophenol-formaldehyde resin nanotubes.

Self nitrogen-doped carbon nanotubes as anode materials for high capacity and cycling stability lithium-ion batteries

The great demand for high-power lithium-ion batteries has spurred extensive research on carbonaceous electrode materials. Herein, we reported a facile way of preparing novel carbon nanotubes with high nitrogen doping. Helical and straight 3-aminophenol formaldehyde resin nanotubes were first prepared based on the self-assembly of the chiral amphiphiles, which were then used as carbon sources to fabricate self nitrogen-doped carbon nanotubes via pyrolysis process. When the resins were carbonized at 600°C, carbon nanotubes with a high nitrogen-content of 9.6wt% were obtained, which maintained the original morphology of the resins. The electrochemical tests disclosed that the carbon nanotubes exhibited excellent Li storage capacity and superior cycling stability. A high reversible specific capacity of 1056mAhg−1 at 0.1Ag−1 was obtained after 300cycles, which is greatly higher than that of graphite and most of polymer derived carbonaceous materials. The research data implied that the nitrogen doping content plays an important role in the electrochemical performance of the carbon nanotubes.

Effect of Processing Conditions on the Mechanical Behavior of Amino Functionalized Nanotube Modified Glass Fiber Epoxy Composites

In the present study ply glass fiber epoxy composites were prepared with amino functionalized carbon nanotubes using Vacuum assisted resin infusion molding VARIM technique The focus is to evaluate the different processing techniques used to uniformly disperse nanotubes in resin and their effect on mechanical properties In addition the dispersion and mechanical performance by incorporating amino nanotubes in curing agent vis agrave vis epoxy resin is also studied Lastly the mechanical behavior of composites on increasing the resin infusion temperature prior to its fabrication is also investigated The mechanical results along with SEM and TEM images validate the proposed processing methodology and use of higher infusion temperature

Synthesis of in-situ high nitrogen-doped helical carbonaceous nanofibers toward high-performance lithium-ion batteries

The great demand for high-power lithium-ion batteries (LIBs) has spurred extensive research on carbonaceous electrode materials. In this work, a novel high nitrogen-doped helical carbonaceous nanofiber derived from pyrolytic resins was fabricated. Helical m-phenylenediamine-formaldehyde resin nanotubes were prepared via a sol-gel duplication method using a chiral amphiphile as the template. Then, the obtained resin nanotubes were subject to carbonize at 600°C under Ar atmosphere, forming helical carbonaceous nanofibers with N content of 12.4wt%. The inner tunnels were disappeared owing to the thermal contraction. Wide angle X-ray diffraction and Raman spectrum analysis verify that the obtained nanofibers were amorphous carbon predominantly. The electrochemical characterization reveals that the in-situ nitrogen-doped carbonaceous nanofibers exhibit high specific capacity, together with long cycle time and excellent rate capability.

Preparation of single-handed helical and C-shaped 3-aminophenol-formaldehyde resin nanotubes and single-handed helical carbonaceous nanotubes

Single-handed helical and C-shaped 3-aminophenol-formaldehyde resin nanotubes were prepared via a supramolecular templating approach. The chiral templates and 3-aminophenol were initially organized into helical nanoribbons, followed by the adsorption of formaldehyde onto the surfaces of the helical nanoribbons. Subsequent to polymerization and further thermosetting of the resin oligomers, 3-aminophenol-formaldehyde resin nanotubes were obtained after removing the templates. When low amounts of 3-aminophenol were added, straight C-shaped 3-aminophenol-formaldehyde resin nanotubes were obtained. Increasing the amount of added 3-aminophenol led to the formation of single-handed helical nanotubes instead. When the single-handed helical resin nanotubes were carbonized at 900 °C under Ar, single-handed helical carbonaceous nanotubes were obtained. Raman spectrum indicates that this carbon is predominantly amorphous. Circular dichroism spectra illustrate that both the helical resin nanotubes and the carbonaceous nanotubes exhibit optical activity. This work indicates that the added amount and the edge-adsorption mode of the precursors on the templates determine the final morphology and chirality of the products.

Single-handed helical carbonaceous nanotubes prepared using a pair of cationic low molecular weight gelators

We design a facile route to obtain enantiopure carbonaceous nanostructures, which have potential application as chiral sensors, electromagnetic wave absorbers, and asymmetric catalysts. A pair of cationic low molecular weight gelators was synthesized, which were able to self-assemble into twisted nanoribbons in ethanol at a concentration of 20gL−1 at 25°C. Single-handed helical 3-aminophenol-formaldehyde resin nanotubes with optical activity were prepared using the self-assembly of the low molecular weight gelators as templates. After carbonization, single-handed helical carbonaceous nanotubes were obtained and characterized using circular dichroism, wide-angle X-ray diffraction, field-emission scanning electron microscopy, transmission electron microscopy, and Raman spectroscopy. The results indicate that the walls of the nanotubes are amorphous carbon. Moreover, the left- and right-handed helical nanotubes exhibit opposite optical activity.

The effect of MWNTs on the microstructure of resin carbon and thermal conductivity of C/C composites

Multi-walled nanotubes were added into furan resin. Unidirectional carbon/carbon preforms were densified with the nanotube-doped furan resin by impregnation–carbonization cycle. The effects of Multi-walled nanotubes on the microstructure of resin carbon and thermal conductivity of carbon/carbon composites were investigated. The results show that Multi-walled nanotubes can induce the ordered arrangement of planar carbon microlites in resin carbon during high-temperature treatment and enhance the graphitization degree of resin carbon. Small amount of Multi-walled nanotubes in resin carbon can enhance the thermal conductivity of C/C composites evidently, especially the thermal conductivity vertical to the direction of fiber axis, due to the improvement of microstructure of resin carbon. Excess Multi-walled nanotubes in resin are disadvantageous to the enhancement of thermal conductivity instead, because they are difficult to disperse and easy to agglomerate, resulting thermal resistances in carbon matrix.

Preparation of well-aligned carbon nanotubes by pyrolysis of phenolic resin in anodic alumina pores

Well-aligned carbon nanotubes (CNTs) of high quality were synthesized by pyrolysis of phenolic resin at 800 °C in anodic alumina oxide (AAO) pores under argon protection. The innocuous source materials and safe operational conditions permit this method to synthesize well-aligned CNTs in large-scale and low cost. The formation mechanism of the synthesized CNTs is also proposed in this work by a series of visual sketches and is proved with obvious evidence. Firstly, phenolic resin nanotubes form in the template pores through the evaporation of solvent. Heat treatment then transfers these tubes into CNTs.