Carbon Nanofiber Composites: From Innovative R&D to Commercial Reality. Carla L. Lake, PhD Applied Sciences Inc 141 W. Xenia Ave Cedarville, Ohio

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1 Carbon Nanofiber Composites: From Innovative R&D to Commercial Reality Carla L. Lake, PhD Applied Sciences Inc 141 W. Xenia Ave Cedarville, Ohio

2 Outline Carbon / Nano carbon Carbon Nanofibers Carbon Nanofibers vs. Carbon Nanotubes Applications Anode Material for Li-ion Batteries Multi-Functional CNF Reinforced Polymers Composites Dispersion of CNF / Dispersion Analysis Environmental, Health and Safety 2

3 Nano Carbon Carbon Nanotubes Carbon Nanofibers Fullerenes Nano graphene

4 Pyrograf-III Carbon Fiber Carbon Nanofibers (CNF) CNF Nested Conic Morphology is Unique Trade name: Pyrograf-III. Diameter: ~ nanometers Provides electrical, structural, and thermal/ ablative properties. Current status: Pilot scale production, intermediate cost. Uses: Conductive polymers, EMI shielding, lightning protection, structural enhancement, ablatives. Potential market: >1500 TpY

5 Carbon Nanofibers Carbon nanofibers (CNF) are a unique form of vapor-grown carbon fiber that bridges the gap in physical properties between larger, conventional PAN or pitch-based carbon fibers (5 10 µm) and smaller single-wall and multi-wall carbon nanotubes (1 10 nm)

6 CNF vs CNT MWCNT CNF Exposed edges along the fiber Benefits of using CNF over CNT Easier to disperse Easier to process Easier to functionalize Simultaneous provides electrical and mechanical property enhancements Lower overall cost of use 6

7 Carbon Nanofibers Structural and transport properties: Diameter: nm Length: > 50 μm Electrical conductivity 1,2 : 1x x10-4 Ohm.cm Tensile strength 1,3 : GPa Surface energy 2 : mj/m 2 PS LHT HHT Heat treatment Temperature/ Surface energy/conductivity 1 M. Endo et al. Carbon 39, p1287, Ozkan et al. Carbon 48, p239, 2010

8 CNF Product forms Powder Diameter Length Surface properties Sheet CNF mat 100 % CNF paper Dispersions Thermoset Thermoplastic masterbatches Tapes Thin films Nanofluids

9 Applications Defense Sporting and electronic goods Automotive

10 Carbon Nanofiber Applications Technical Readiness Level TRL 9 TRL 8 TRL 7 TRL 6 TRL 5 Aerospace Structural Components Anti-Corrosion/Erosion Coatings Conductive Inks Thermally Conductive Grease ESD Components Conductive thin films Li-ion batteries ESD Carpets/Fabrics Electronic Device Shielding Fire Retardant Foam Automotive Panels Conductive Thin Films Multi-functional/Structural Composites Sporting Goods Audio Equipment TRL 4 TRL 3 Biosensors/Smart Composites Solar Cells Biomedical Applications TRL 2 TRL 1 Continuous Filaments For Non-metallic Cable & Wiring Space Elevator 10

11 High Capacity, High Power Anode Materials for Energy Storage

12 Anode Materials for Li-ion Batteries Automotive Wang C.M. et al. Nano Letters 2012

13 Anode Materials for Li-ion Batteries Defense

14 Anode Materials for Li-ion Batteries Four Times Greater Charge Capacity for Silicon Coated Carbon Nanofiber Anode (C-Si) compared to graphite (LiC 6 ) 14 MN8277, Charge-Discharge efficiency of C-Si Capacity (mah/g)/ C-Si LiC Cycle number

15 Anode Materials for Li-ion Batteries TEM image of CNF coated with a thin layer of silicon prior to electrochemical cycling. TEM image of silicon coating after 100 electrochemical cycles. These images clearly show that the silicon has expanded but is still chemically bonded, and electrically connected, to the CNF after 100 charging/discharging events.

16 Multi-Functional CNF Reinforced Polymer Composites

17 Advantages of Carbon Nanofibers Functional and morphological merits of CNFs for polymeric applications: High aspect ratio (l/d) Thermal conductivity up to 5 x copper Electrical conductivity overlaps metals Multi-functionality Easier to disperse than CNTs 1 Higher chemical reactivity Recyclability Reduced linear thermal expansion dimension stability Available in high volumes at a competitive price High quality 1 M.Nyden,Polymer, 49: p. 635, (2008).

18 Tailorable Electrical Conductivity CNF LOADING Lightning strike protection EMI/RF Shielding < 10 Ω.cm Antistatic clean rooms, fuel lines > 10 6 Ω-cm Electrostatic painting automobiles Ω-cm 18

19 Electrostatic painting Benefits of using CNFs Achieve electrostatic conductivity at low loading levels Smooth surface finishes No primer required Online painting Higher transfer efficiency Environmental friendly Van Hattum et al. in Plast., Rubber Compos.: Macromol. Eng., vol. 35, 6/7 (200 6) 19

20 ESD/Wear pulleys Material: PP/CNF;Pa6/CNF;PEEK/CNF Benefits of using CNFs Multifunctionality Achieve ESD conductivity at low loading levels 3 wt% CNF translates into a 4 fold improvement on wear Lower coefficient of friction Reported 20% energy savings in conveyor systems From: Tribology of Polymeric Nanocomposites Klaus Friedrich Elsevier

21 Direct part manufacturing CNF have been identified as a strategic material to be used as reinforcements and electrical conductive additives in thermoplastic polymers for direct part manufacturing Benefits of using CNFs Multifunctionality Isotropy Reduced filler loading Achieve ESD conductivity at low loading levels Mechanical reinforcement Decreased energy density

22 Direct part manufacturing Voids = Loss of mechanicals in the Z direction Fillers help with consolidation. B.P. Rice, DPM Workshop, Fairborn, OH, March 2011 R.D. Goodridge et al., Polymer Testing 30 (2011) L. Folgar. Laser sintering of nanocomposites DPM Workshop, Fairborn, OH, March 2011.

23 Challenges At a nanoscale: Surface effects dominate and Van der Waals forces become important! Dispersion CNF cohesion: geometry; surface chemistry and energy Resin chemistry and viscosity Highly dependent on processing conditions

24 Challenges Processing/Mixing Mixing conditions have the highest impact on the properties that rely on a network formation: electrical resistivity, thermal stability and on the melt flow properties of the nanocomposites. Volume resistivity [Ohm.cm] Mixing energy/deformation CNF loading [wt%]

25 Solutions Understanding and monitoring DISPERSION of CNF is KEY to overcome these challenges and improve the fidelity of its nanocomposites! Determine the effect of processing conditions (i.e. shear history, residence time, deformation) on the dispersion of CNF in polymeric resins. Modeling the effect of CNF dispersion on properties like electrical conductivity and mechanical reinforcement. Product solutions that supersede agglomeration tendency of nano carbons. 25

26 Product Solutions MASTERBATCHES 5 20 wt% PP, HDPE, PS; NANOMAT PA6, PA12, PC; TPU PEEK, PEI, PEKK PRE-DISPERSIONS EPOXY VINYL ESTHERS BMI 26

27 Carbon Nanomaterials Dispersion Analysis Method

28 How can we monitor dispersion in nanocomposites? Same filler, same loading Klaus Friedrich HDPE/ 5wt%CNF Masterbatches 50 µm 3 different processing conditions 3 different dispersion levels 3 different composites Most methods used for assessing fiber dispersion are subjective, non-reproducible and with a limited sampling area 28

29 Dispersion vs Mixing Energy Increase in dispersion with mixing energy 29

30 Dispersion vs CNF Fiber Length 2.5 lb/ft lb/ft lb/ft lb/ft µm 30

31 Dispersion vs CNF Fiber Length Improved dispersion with shorter fibers (up to 4.5lb/ft 3 ) 5000 Variance [-] lb/cu.ft 3.5 lb/cu.ft 4.5 lb/cu.ft 6.0 lb/cu.ft Length scale [µm] 31

32 Multi-scale image analysis (MSIA) Use: Quality control tool Define processing conditions Compare fiber types/grades Compare fiber lengths Compare between polymer matrices

33 Environmental Health and Safety

34 PPI s Proactive Approach to EH&S NIOSH is continually performing air quality assessments at PPI NIOSH results assisted PPI in selecting appropriate PPE (see MSDS) and safe manufacturing methods When mutually agreed upon, PPI will ship CNF product in containers that connect directly with customer s on-site storage container or processing equipment Shipping containers will be returned to PPI and re-used 34

35 Consent Order Requirements Imported or domestically manufactured nanomaterials used in commercial products must be listed under The Toxic Substances Control Act (TSCA) Section 8(e) CO specifies personal protective equipment (PPE) for PPI workers and customers, recordkeeping, and specialized testing required for compliance CO enables the use of all PPI s CNF products to be included in domestic, commercial applications CO covers all milled and non-milled PR-19 and PR-24 CNF types in all three grades (PS, LHT, HHT) 35

36 PPE Requirements Respiratory Protection NIOSH certified air-purifying, tight-fitting full-face respirator equipped with N-100, P-100, or R-100 filter with an APF of 50 or greater Dermal Protection gloves impervious to PMN substances full body clothing impervious to PMN substances (demonstrated by ASTM F739) PPE should be used with appropriate engineering controls 36

37 Contact information Questions? Contact info: Dr. Carla Leer-Lake Applied Sciences Inc Ph: ext 134 Also visit: