Multi-walled Carbon Nanotube Fibers Research Articles

Leveraging Oriented Lateral Walls of Nerve Guidance Conduit with Core-Shell MWCNTs Fibers for Peripheral Nerve Regeneration.

Peripheral nerve regeneration and functional recovery rely on the chemical, physical, and structural properties of nerve guidance conduits (NGCs). However, the limited support for long-distance nerve regeneration and axonal guidance has hindered the widespread use of NGCs. This study introduces a novel nerve guidance conduit with oriented lateral walls, incorporating multi-walled carbon nanotubes (MWCNTs) within core-shell fibers prepared in a single step using a modified electrohydrodynamic (EHD) printing technique to promote peripheral nerve regeneration. The structured conduit demonstrated exceptional stability, mechanical properties, and biocompatibility, significantly enhancing the functionality of NGCs. In vitro cell studies revealed that RSC96 cells adhered and proliferated effectively along the oriented fibers, demonstrating a favorable response to the distinctive architectures and properties. Subsequently, a rat sciatic nerve injury model demonstrated effective efficacy in promoting peripheral nerve regeneration and functional recovery. Tissue analysis and functional testing highlighted the significant impact of MWCNT concentration in enhancing peripheral nerve regeneration and confirming well-matured aligned axonal growth, muscle recovery, and higher densities of myelinated axons. These findings demonstrate the potential of oriented lateral architectures with coaxial MWCNT fibers as a promising approach to support long-distance regeneration and encourage directional nerve growth for peripheral nerve repair in clinical applications.

Wet spinning of multi-walled carbon nanotube fibers

For the commercialization of macroscopic fibers of carbon nanotubes (CNTs), it is important to achieve solution processing using inexpensive commercial multi-walled carbon nanotubes (MWCNTs). However, so far, the solution processing of CNTs has been limited to single-walled CNTs (SWCNTs). Here, we report wet spinning of MWCNT fibers using a high-concentration MWCNT/surfactant dispersion in water for the first time. We established the phase diagram of MWCNT/surfactant dispersion by varying the mass ratio of surfactants and MWCNTs. The phase diagram successfully accounts for the phase behavior based on the balance between depletion-induced attraction from surfactant micelles and electrostatic repulsion from adsorbed surfactants on MWCNTs. Following the phase diagram, we obtained a homogeneous MWCNT dispersion with high concentration (1.4 wt%), which enabled us to fabricate MWCNT fibers by wet spinning.

Development of single‐polypropylene composites interleaved with MWCNT‐doped melt‐blown fine fiber mats

AbstractIn this article, we demonstrate fabricating polypropylene (PP)/multiwalled carbon nanotube (MWCNT) nanocomposite fiber veils and use them as interleaves in single‐polymer composites (SPCs) to enhance their thermal and mechanical properties. With this regard, we produced a hierarchical composite structure made of a film, a woven fabric and a fine fiber mat made of the same polymer. The nanocomposite fiber mats were generated by melt‐blowing. Results implied that incorporating MWCNT increased the viscosity of the melt blowing grade PP resin. Increasing MWCNT content increased the average fiber diameter and pore size by 2.1‐fold and 2.5‐fold, respectively. Incorporating MWCNT enhanced the melt‐blown (MB) fiber mat's specific strength by 78% and improved the thermal stability. We generated multiscale SPCs by film‐stacking, for which we applied a PP film as a matrix, a PP‐woven fabric as the primary reinforcement, and the MB fiber mats as interleaves. The SPC's tensile modulus was improved by 37% by the interleaving. Our findings implied that the MWCNT‐doped PP fiber mat interleaving provides a robust interfacial adhesion and higher damage tolerance under tensile load. Master curves were constructed from dynamic mechanical analysis frequency sweep tests based on the time–temperature superposition principle. The storage modulus increased by 33%, while the tanδ decreased around 10% with PP/MWCNT fiber mat interleaving. The developed multiscale SPC with MWCNT fiber mat interleaving veils may be easily integrated into engineering composite applications due to its cost‐efficiency, fair recycling, straightforward processing, enhanced stiffness, and interfacial adhesion.

Effect of fly ash cenospheres on properties of multi-walled carbon nanotubes and polyvinyl alcohol fibers reinforced geopolymer composites

This article proposes a lightweight engineered geopolymer composite (LW-EGC) that combines functionalized multi-walled carbon nanotubes (MWCNTs) and polyvinyl alcohol (PVA) fibers, with fly ash cenospheres (FAC) used as lightweight filling materials. The tensile and bending properties of LW-EGC were studied using a uniaxial tensile test and four-point bending test. The relationship between ultimate tensile strain and mid-span displacement was discussed. The crystal composition and chemical bond of raw materials and LW-EGC were characterized by X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FT-IR), and the micromorphology was analyzed via field emission scanning electron microscopy (FESEM). The test results showed the following: (1) When 10% mass fraction of FAC was added, LW-EGC-10% had a compressive strength of 33.7 MPa, a density of 1522 kg/m3, a flowability of 255 mm, and a tensile strain capacity of 6.03%. (2) The crack width of LW-EGC was generally less than 90 μm, and the crack spacing was generally less than 2 mm with the introduction of FAC, which indicates excellent crack control ability. (3) The XRD spectra indicated that the production of new crystal images was not significant in the geopolymerization, and the FT-IR spectra showed that the reaction products were mainly new aluminosilicate phases. (4) During the extraction of MWCNT and PVA fibers, large extrusion deformation occurred, leaving a large number of broken matrix and FAC fragments on the fiber surface, which made the LW-EGC have excellent tensile strain capacity. The results show that FAC is a promising material for the production of ductility and lightweight structural components with potential for correct processing and efficient recovery of FAC.

Nonmonotonic piezoresistive fibers tuned towards biomechanical sensing

Tuning nonmonotonic piezoresistive materials to detect motions within certain strain limits remains an open challenge. In addition, the origin of this unusual form of piezoresistance is still not properly understood especially for semi conducting polymer nanocomposites containing carbon nanotubes. In this work, we report wet spun nanocomposite fibers based on Poly (ether-block-amide) (PEBA) and multiwalled carbon nanotubes (MWCNT) that show differential sensitivity under uniaxial loading. This nonmonotonic piezoresistance is triggered by yielding of polymer segments which later influences the interaction between the embedded MWCNT at higher draw ratios. We confirmed this observation by correlating the stress – strain curve with the resistance – strain response and further studied its influence on the strain sensing phenomena of PEBA / MWCNT fibers. Moreover, pre-stretched fibers at draw ratios slightly above the yield point produced stable and reproducible sensing signals after applying them as biomechanical sensors for motions associated with small bending radii such as finger-wagging.

Synergistic Effect of MWCNT and Carbon Fiber Hybrid Fillers on Electrical and Mechanical Properties of Alkali-Activated Slag Composites

Herein, we investigated the synergistic effect of multi-walled carbon nanotube (MWCNT) and carbon fiber (CF) hybrid fillers on electrical and mechanical characteristics of alkali-activated slag (AAS) composites. Many studies on AAS composites have been conducted in the past; however, not much progress has been made regarding characteristics of AAS composites with hybrid conductive fillers. The specimens with different mix proportions were fabricated in the present study, and numerous material characteristics, including flowability, electrical resistivity, and compressive strength of AAS composites were measured. In addition, the synergistic effects were investigated through scanning electron microscopy and thermogravimetric analysis. It was found that the 0.5 wt.% of MWCNTs and CFs lead the effects of the bridging and reducing crack propagation, thereby improving its electrical and mechanical performances. The filler exceeding a percolation point improved the electrical performance of the AAS composites; however, it interfered with the hydration process during the curing period, and caused a decrease in compressive strength of AAS composites.

Morphological and Electrical Properties of Multi-Walled Carbon Nanotube-based Fiber Using General Wet-spinning and Alkaline Post-treatment Methods

In this study, we report the structural features and electrical properties of a multi-walled carbon nanotube (MWCNT)-based fibers, composed entirely of MWCNTs or a large fraction of MWCNTs, using traditional fiber-manufacturing techniques inspired from classical methods applied in the creation of polyester or nylon microfibers. To obtain the MWCNT-based fibers used in this study, as-spun fibers designed to achieve 20 wt% poly(ethylene glycol)-functionalized MWCNTs and 80 wt% alkali-soluble elastomeric copolyester were prepared using a conventional wet-spinning process, and the copolyester was then sequentially removed from the as-spun fiber through an alkaline post-treatment process. As a result, we obtained a final unique MWCNT-based fiber with a MWCNT content of close to 80 wt%. The results of a morphological characterization show clearly that the surface of the fiber is mostly composed of MWCNTs with a compact structure. In addition, the MWCNT-based fiber exhibited an improved electrical conductivity of 1.9×102 S/cm, which is similar to the results of the pure or neat MWCNT-based fibers that we previously investigated. Overall, it was confirmed that the traditional approach for MWCNT-based fibers on this study have a significant potential for producing MWCNT-based fibers close to pure or neat MWCNT fibers even when using general fiber-manufacturing techniques.

Diamond-graphite nanocomposite synthesized from multi-walled carbon nanotubes fibers

Creation of the hybrid nanostructures with superior properties that combine the advantages of hardest diamond and flexible graphite remains challenging in experiment. Here we report a new strategy for the synthesis of diamond-graphite hybrid nanocomposite from multi-walled carbon nanotubes fibers by laser heating diamond anvil cell. A combined theory experiment approach confirms the formation of diamond-graphite hybrid structure with the coherent interface consisted of covalent bonds between diamond and graphite. This opens an avenue for the synthesis of diamond-graphite hybrid structure, which may be extended to generate new carbon nanocomposites using other suitable carbon precursors by high pressure.

Electrochemistry of Controlled-Diameter Carbon-Nanotube Fibers at the Cross Section and Sidewall

Electrochemistry at open ends and sidewalls of carbon nanotubes (CNTs) has been under debate, with opposing viewpoints as to which sites are more electro-chemically active. A particular challenge in this field has been the ability to conduct electrochemical studies at the open ends of CNTs, without measuring contributions from the sidewalls. Among the detailed studies on CNT electrochemistry by various research groups, no reports show a direct comparison between the electrochemistry of open ends and sidewalls. That is to say, electrochemical studies at open ends have always had some contribution from sidewalls. Multiple research groups have reported electrochemistry at CNT sidewalls and close ends, although there are no reports that examine the electron transfer rate at open ends exclusively. In cases where rapid electron transfer at open ends has been reported, this has been on either defective dispersed CNTs at an electroactive surface, or on vertically aligned CNTs which are inherently porous. More interestingly, it was also observed that the electrochemical response at CNT modified electrode surfaces could be dominated by thin layer cell behavior, which arises due to the change in diffusional regime or mass transport. Therefore, in such electrode assemblies, we cannot completely assign the electrochemical response to open ends since sidewalls also contributed significantly to the measured current. In this work, we report on electrochemical measurements taken from the sidewall and the cross-section (i.e., open ends) of highly densified multi-walled carbon nanotube fiber (HD-CNTfs) embedded in a polymer matrix. The cross section of the HD-CNTfs was exposed to reveal only open ends to the electrolyte interface and this platform allowed us to compare electrochemistry at the open ends and sidewalls of HD-CNTfs. Cyclic voltammetry was employed to examine the electrochemical properties of HD-CNTfs using a conventional bulk electrochemical cell and micro-capillary electrochemical measurements. The cross sections and side walls of HD-CNTfs are shown to promote similar electron transfer kinetics with reversible redox behavior. However, side walls of HD-CNTfs also showed large capacitive background current which was found to increase in proportional to CNT fiber diameter. Figure 1

Transformation of carbon dioxide into carbon nanotubes for enhanced ion transport and energy storage.

The synthesis of carbon nanotubes (CNTs) from CO2 is an attractive strategy to reduce CO2 emission, but involves extreme reaction conditions and has low scalability. This work introduces continuous chemical vapor deposition for the conversion of CO2 to CNTs using the NaBH4 reductant and NiCl2 catalyst. Multi-walled CNT fibers were synthesized from gaseous CO2 under mild conditions (500-700 °C and 1 atm). Based on in situ analyses, the proposed mechanism behind the formation of CO2-derived CNTs (CCNTs) is CO2 activation and subsequent hydroboration for the generation of methane, which can induce the growth of CCNTs on the catalyst. Their intrinsic properties give rise to an enhanced capacitive performance. The boron and oxygen of CCNTs provide a pseudo-capacitance of 302 F g-1 at a low charging rate of 0.1 A g-1 in 1 M TEABF4/acetonitrile. The mesoporous networks between CCNT fibers enhance ion transport at a high current density of 205 A g-1, leading to an outstanding energy density of 13 W h kg-1 at a high power density of 115 kW kg-1. A well-developed graphitized structure of CCNTs contributes to the reduction of the electrochemical resistance and leads to their superior stability at 65 °C during 10 000 cycles.

Effective stress transferring interface and mechanical property enhancement of poly(l-lactide)/multi-walled carbon nanotubes fibers

The poly(l-lactide) grafted multi-walled carbon nanotubes (MWNT-g-PLLA) was firstly prepared, and a maximum grafting amount of 31 wt% was obtained by optimizing grafting reaction conditions. Then the PLLA/MWNT-g-PLLA composite fibers were fabricated by melt spinning, and showed significant enhancement of tensile strength and elongation at break, comparing with the unmodified PLLA/MWNTs or pure PLLA ones. Structure analysis of as-spun fibers revealed uniform dispersion of MWNT-g-PLLA in PLLA matrix on account of good interfacial compatibility, which could prevent premature interface damage and ensure the continuous deformation of fibers under stress. The crystal morphology of strain hardening before unbroken fibers were expressly observed, suggesting a possible stretching induced formation of nano-hybrid shish-calabash similar to structure in which the PLLA lamellae growing onto the MWNT-g-PLLA axis. This interface crystallization greatly improved the interfacial stress transferring between PLLA and MWNT-g-PLLA, thus resulted in notable promoted tensile strength and elongation at break.

Structures, electrical and mechanical properties of epoxy composites reinforced with MWCNT-coated basalt fibers

We report the structures, electrical and mechanical properties of a series of epoxy composites reinforced with multi walled carbon nanotube (MWCNT)-coated basalt fibers. For the purpose, MWCNT-coated basalt fibers were obtained by cyclic dip-dry coating process of neat basalt fibers in an aqueous MWCNT dispersion containing sodium dodecyl sulfate (SDS) surfactant, and they were composited with epoxy resin by hand lay-up method. The FT-IR and Raman spectroscopic analyses revealed the presence of the specific interactions between MWCNT and basalt fibers via SDS surfactant. Accordingly, the content of MWCNT coated on basalt fibers was measured to increase with the dip-dry coating cycle from 0 to 10. The electrical conductivity of the epoxy composites with MWCNT-coated basalt fibers increased significantly from 3.25 × 10−9 S/cm to 1.44 × 10−1 S/cm with increasing the dip-dry coating cycle. The composites with MWCNT-coated basalt fibers fabricated by above 2 cycles of dip-dry coating exhibited excellent electric heating performance in terms of rapid temperature responsiveness, high steady-state maximum temperature, high electric power efficiency, and stable operational stability under applied voltages. In addition, the epoxy composites with MWCNT-coated basalt fibers fabricated by one or two dip-dry coating cycle were found to have highly improved flexural mechanical properties, compared to the epoxy composite reinforced with neat basalt fibers.

Photo-thermal conversion properties of hybrid CuO-MWCNT/H2O nanofluids for direct solar thermal energy harvest

Water-based hybrid nanofluids with CuO and multi-walled carbon nanotube (MWCNT) were prepared and well dispersed. The optical absorption properties and photo-thermal conversion performance of hybrid CuO-MWCNT/H2O nanofluids at different concentration mixing ratios (CMRs) were experimentally tested and compared to evaluate the solar thermal energy harvest capability. The mixture of CuO-MWCNT nanofluids significantly enhanced solar energy spectral absorption as compared with individual CuO or MWCNT nanofluids, and the extinction coefficients of hybrid nanofluids were mostly equal to the sum of individual components. At appropriate CuO/MWCNT CMRs, the solar weighted absorption fractions of hybrid nanofluids are almost 100% at an optical penetration distance of 1 cm. Besides, the photo-thermal conversion performance of hybrid nanofluids was largely superior to individual nanofluids but highly dependent on the CMR, and an excessive addition of individual component could lower the performance. At a CuO/MWCNT CMR of 0.15 wt%/0.005 wt%, a maximum terminal temperature rise of 14.1 °C was achieved with respect to DI water after a light irradiation time duration of 45 min. The coexistence and interaction of CuO nanoparticles and MWCNT fibers in the aqueous suspension at evaluated temperatures were took into account to explain the optical absorption behavior and then the photo-thermal conversion properties. This study suggests that hybrid CuO-MWCNT/H2O nanofluids at appropriate CMRs provide a potential alternative in direct solar thermal energy harvest.

Persistent Pleural Lesions and Inflammation by Pulmonary Exposure of Multiwalled Carbon Nanotubes.

Translocation of multiwalled carbon nanotubes (MWCNTs) from the lung to the pleural cavity, deposition of the fibers in the pleural tissue, induction of pleural fibrosis, and mesothelial proliferation have been found inrodents administered MWCNTs by different pulmonary exposure methods. However, whether the translocation and deposition and the subsequent pleural inflammation are associated with the pleural lesions is unclear. In the present study, male F344 rats were given 250 μg of two types of MWCNTs, with crocidolite as a positive control, 2 times/week for 4 weeks by intratracheal spraying. At 24 h and at 3 months after the last spraying, the rats were sacrificed for histological examination of the lung and chest wall; pleural cavity lavage was also collected at sacrifice for observation of pleural inflammatory reactions. The results indicated that intratracheally sprayed MWCNTs, like crocidolite fibers, translocated into the pleural cavity, deposited in the pleura, and induced persistent infiltration of immune cells into the pleural cavity, persistent pleural fibrosis, and mesothelial proliferation. The number of MWCNT fibers detected in the pleural cavity lavage was parallel to the number of infiltrating immune cells, which were mainly composed of macrophages. Analysis of cytokines in the fluids of the pleural cavity lavages by suspension array indicated that levels of IL-2, IL-18, and IP-10 were significantly increased both at 24 h and at 3 months after the last spraying. In vitro proliferation assays revealed that a mixture of IL-2, IL-18, and IP-10, but not any of these cytokines alone, promoted cell proliferation of human fibroblasts and mesothelial cells. These results suggest that translocated and deposited MWCNTs induce subsequent pleural inflammation and that increased IL-2, IL-18, and IP-10 synergistically promote the development of pleural fibrosis and mesothelial proliferation.

Carcinogenicity of multi-walled carbon nanotubes: challenging issue on hazard assessment.

Objectives: This report reviews the carcinogenicity of multi-walled carbon nanotubes (MWCNTs) in experimental animals, concentrating on MWNT-7, a straight fibrous MWCNT. Methods: MWCNTs were administered to mice and rats by intraperitoneal injection, intrascrotal injection, subcutaneous injection, intratracheal instillation and inhalation. Results: Intraperitoneal injection of MWNT-7 induced peritoneal mesothelioma in mice and rats. Intrascrotal injection induced peritoneal mesothelioma in rats. Intratracheal instillation of MWCNT-N (another straight fibrous MWCNT) induced both lung carcinoma and pleural mesothelioma in rats. In the whole body inhalation studies, in mice MWNT-7 promoted methylcholanthrene-initiated lung carcinogenesis. In rats, inhalation of MWNT-7 induced lung carcinoma and lung burdens of MWNT-7 increased with increasing concentration of airborne MWNT-7 and increasing duration of exposure. Conclusions: Straight, fibrous MWCNTs exerted carcinogenicity in experimental animals. Phagocytosis of MWCNT fibers by macrophages was very likely to be a principle factor in MWCNT lung carcinogenesis. Using no-observed-adverse-effect level-based approach, we calculated that the occupational exposure limit (OEL) of MWNT-7 for cancer protection is 0.15 μg/m3 for a human worker. Further studies on the effects of the shape and size of MWCNT fibers and mode of action on the carcinogenicity are required.

Electrodes of carbonized MWCNT-cellulose paper for supercapacitor

A flexible composite paper of multi-walled carbon nanotube (MWCNT) and cellulose fiber (CF) were fabricated by traditional paper-making method. Then, the MWCNT/CF papers were carbonized at high temperature in vacuum to remove organic component. The carbonized MWCNT/CF (MWCNT/CCF) papers are consisted of MWCNT and carbon fiber. The papers were characterized by scanning electron microscope (SEM), X-ray diffraction (XRD), and four-point probe resistance meter. The electrochemical performances of the supercapacitors were tested by cyclic voltammetry and galvanostatic charge/discharge >with 1 moL/L LiPF6 as electrolyte. The MWCNT/CCF electrode yielded a specific capacitance of 156F/g at a current density of 50 mA/g by galvanostatic charge/discharge measurement, which is 1.29 times higher than MWCNT/CF electrode of 68F/g. The MWCNT/CCF electrodes also displayed an excellent specific capacitance retention of 84% after 2000 continuous charge/discharge cycles at a current density of 400 mA/g. The increase of specific capacitance can be attributed to enhanced electrical conductivity of MWCNT/CCF papers and improved contact interface between electrolyte and electrodes.

Stromelysin-2 (MMP-10) facilitates clearance and moderates inflammation and cell death following lung exposure to long multiwalled carbon nanotubes.

Multiwalled carbon nanotubes (MWCNTs) are nanomaterials composed of multiple layers of graphene cylinders with unique properties that make them valuable for a number of industries. However, rising global production has led to concerns regarding potential occupational exposures to them as raw materials during handling. This is especially true for long MWCNT fibers, whose aspect ratio has been posited to initiate pathology similar to that of asbestos. Matrix metalloproteinases (MMPs) are a class of extracellular endopeptidases that control various processes related to tissue repair, inflammation, and more. Stromelysin-2 (MMP-10) has roles in modulating macrophage activation and function, and hence, we used an MMP-10 null (Mmp10−/−) mouse model to assess its role in controlling lung responses to inhaled long MWCNTs. Oropharyngeal aspiration of long MWCNTs (80 µg/mouse) by wild-type mice induced expression of Mmp10 mRNA, which was accompanied by a robust inflammatory response characterized by elevated expression of Tnfa, Il6, and Il1b. In Mmp10−/− mice, we found that absence of MMP-10 led to impaired pulmonary clearance of MWCNTs and reduced macrophage cell survival. Exposure of wild-type bone marrow-derived macrophages (BMDMs) and alveolar macrophages to MWCNTs caused a rapid, dose-dependent upregulation of Mmp10 mRNA expression, which was accompanied by expression of pro-inflammatory products (Il6 and Il1b). These products were further enhanced in Mmp10−/− macrophages, resulting in increased caspase-3-dependent cell death compared with wild-type cells. These findings indicate that MMP-10 facilitates the clearance of MWCNTs and moderates the pro-inflammatory response of exposed alveolar and infiltrated macrophages.

Flexible, Low Cost, and Platinum-Free Counter Electrode for Efficient Dye-Sensitized Solar Cells.

A platinum-free counter electrode composed of surface modified aligned multiwalled carbon nanotubes (MWCNTs) fibers was fabricated for efficient flexible dye-sensitized solar cells (DSSCs). Surface modification of MWCNTs fibers with simple one step hydrothermal deposition of cobalt selenide nanoparticles, confirmed by scanning electron microscopy and X-ray diffraction, provided a significant improvement (∼2-times) in their electrocatalytic activity. Cyclic voltammetry and electrochemical impedance spectroscopy suggest a photoelectric conversion efficiency of 6.42% for our modified fibers, higher than 3.4% and 5.6% efficeincy of pristine MWCNTs fiber and commonly used Pt wire, respectively. Good mechanical and performance stability after repeated bending and high output voltage for in-series connection suggest that our surface modified MWCNTs fiber based DSSCs may find applications as flexible power source in next-generation flexible/wearable electronics.

Electrospun Poly(lactic-co-glycolic acid)/Multiwalled Carbon Nanotube Nanofibers for Cardiac Tissue Engineering

Many conductive scaffolds were fabricated to mimic the topography of the cardiac microenvironment in vitro in order to improve the performance of engineered cardiac tissues. This study fabricated aligned poly(lactic-co-glycolic acid)/multiwalled carbon nanotube fibers by electrospinning. The Young's modulus and conductivity were significantly greater on poly(lactic-co-glycolic acid) fibers with 3% multiwalled carbon nanotubes compared to others. Topographical cues and conductivity were applied to investigate the combined effect on cardiomyocyte behavior. Neonatal rat cardiomyocytes cultured on the conductive fibers maintained their viability, induced cell elongation, and enhanced sarcomeric α-actinin and troponin I production in cardiomyocytes. The results indicate that poly(lactic-co-glycolic acid)/multiwalled carbon nanotube composite fibers have great potential for cardiac tissue engineering.

Templated CaCO3 Crystallization by Submicrometer and Nanosized Fibers.

Electrospun submicrometer-sized poly(ε-caprolactone) (PCL) meshes and nanosized multiwalled carbon nanotubes (MWCNTs) were used as a template for preparing porous and interconnected inorganic-organic hybrid materials composed of CaCO3. Herein, we describe the proportion and incorporation method of submicrometer-sized plasma-treated PCL meshes over areas >1 mm(2) with CaCO3 using three crystallization methods including the use of poly(acrylic acid) (PAA). We found that flexible and rigid acid-functionalized MWCNTs showed a clear capacity and effects to penetrate calcite particles. MWCNTs interacted differently with the individual growth planes of CaCO3, indicating that fibers can undergo changes depending on sulfonate or carboxylate groups, adopt different orientations in solution, and thereby elicit changes in CaCO3 morphology. In summary, the use of PCL and acidic MWCNT fibers as an additive for substrate templates and experimental crystallization provides a viable approach for studying various aspects of biomineralization, including the production of controlled particles, control of porosities, and defined morphologies at microscale and nanoscale levels.