Water-Based Colloidal Exfoliation Techniques for the Production of Graphene Nanoplatelets

By AZoNano.com Staff Writers

Topics Covered

Introduction
LUMiSizer and STEP Technology
About Grafen Chemical Industries
About LUM GmbH

Introduction

Grafen Co. (Turkey) and LUM (Germany) began a joint research on water-based colloidal exfoliation processes to produce graphene nanoplatelets in bulk scale. The innovative method, liquid phase, direct chemical exfoliation enables industrial manufacturing of graphene with a green approach at a low cost. The initial phase of the research has been completed giving substantial results and future plans call for larger work to gain technological understanding.

The Founder and Chief Science Officer of Grafen Co stated that he looked forward to working together with LUM as the knowledge and expertise of LUM in colloidal chemistry, physics and characterization of liquid suspensions, emulsions and other complex liquids perfectly complement decade-long experience of Grafen Co. in carbon nanomaterials.

Liquid phase direct chemical exfoliation is a potential research direction in the field of graphene production aiming direct conversion of large volumes of raw graphite powder into the final graphene product with nearly pristine crystal structure and physical properties unlike any other graphene synthesis techniques. Graphen Co makes use of aqueous surfactant solutions as exfoliation media that target specifically to avoid toxicity of those organic solvents.

LUMiSizer and STEP Technology

LUM shares its expertise in colloidal stability of complex fluids to study the graphene production process developed by Grafen Co. Stability of graphene suspensions is characterized by cutting-edge LUMiSizer® systems from LUM GmbH. LUMiSizer® using STEP-Technology® as seen in Figure 1 is an industry standard for consistent and fast determination of stability of colloids. Conventionally, stability analysis of graphene suspensions to decide best formulations for exfoliation is a tedious job; however, LUMiSizer® allows extremely rapid implementation of the experiments. 

Figure 1. LUMiSizer® and STEP-Technology® from LUM GmbH.

The right surfactant types for bulk production are revealed by initial phase research on time-dependent sedimentation velocity of graphene nanoplatelets as seen in Figure 2. Graphene can be more stable in non-ionic surfactants that is in agreement with the scientific literature. Those findings will guide the direction of the next step in this research collaboration. Colloidal stability may also provide new insights into graphene exfoliation mechanism in liquids and help to improve industrial manufacturing technology.

Figure 2. Sedimentation velocity of graphene suspensions developed by Grafen Co.Left, transmission profile of the graphene suspension in Tween 80 solution, 2 hours centrifugation at 36 g 20°C (every 10th profile displayed, red – first profiles, green – last profiles).Right, comparison of kinetics of clarification, 36 g, 20°C (transmission averaged over the sample range 115 – 125 mm).

About Grafen Chemical Industries

Grafen Chemical Industries (GCI) is a leader in the fabrication and application of carbon nanomaterials, novel family of broad range of materials with miraculous electrical, mechanical, chemical and thermal properties. Products offered by GCI include advanced carbon nanomaterials, particularly graphene and carbon nanotubes, as well as cutting-edge technologies based on carbon based nanodevices.

Works in GCI, in addition to nanomaterial manufacturing, focus on industrial organic electronics, high performance materials and green chemistry. Under these titles, our team has developed electrically conductive plastics, electromagnetic shielding paints, nanocomposite ballistic protection textiles, low- permeability active packaging films, phytochemical antimicrobials, self-cleaning coatings and toxic waste management processes.

About LUM GmbH

LUM GmbH is the leading company in the field of accelerated dispersion and stability analysis and testing of composite materials. They offer innovative solutions for real-time and accelerated analysis in the following fields:

  • dispersion analysis
  • stability analysis
  • separation analysis
  • particle sizing
  • material testing

LUM instruments are found in international chemical, food, cosmetics, pharmaceutical and most other industrial branches.

LUM GmbH also offers analytical services in the fields mentioned above.

Date Added: Nov 28, 2013 | Updated: Dec 3, 2013
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