An Experimental Evaluation of Thermal Conductivity of Colloidal Suspension of Carbon-Rich Fly Ash Microparticles and Diamond-Nano Powder (DNP) in Jet-A Fuel

At a Glance

Metadata	Details
Publication Date	2025-07-01
Journal	Proceedings of the … International Conference on Fluid Flow, Heat and Mass Transfer
Authors	Ahmed Aboalhamayie
Analysis	Full AI Review Included

Technical Documentation & Analysis: Diamond Nanopowder for Enhanced Thermal Conductivity in Jet-A Fuel

This document analyzes the findings of “An Experimental Evaluation of Thermal Conductivity of Colloidal Suspension of Carbon-Rich Fly Ash Microparticles and Diamond-Nano Powder (DNP) in Jet-A Fuel” to provide technical specifications and align 6CCVD’s advanced MPCVD diamond capabilities with the research requirements.

Executive Summary

This research validates the use of Diamond Nano Powder (DNP) as a high-performance additive for enhancing the thermal conductivity of Jet-A fuel, a critical parameter for aerospace and energy applications.

Core Achievement: A 2 wt.% concentration of Diamond Nano Powder (DNP) successfully increased the thermal conductivity of Jet-A fuel by 2.023%.
Performance Benchmark: The final thermal conductivity reached 1.015 W/m·°C at 2 wt.% DNP, demonstrating the material’s intrinsic thermal superiority over the baseline fuel (0.995 W/m·°C).
Material Properties: DNP utilized was characterized by an ultra-fine particle size (3-10 nm) and an extremely high specific surface area (SSA) of approximately 280 m²/g.
Methodology: Colloidal suspensions were stabilized using a hybrid two-step method involving Span 80 surfactant addition and 45 minutes of sonication (30% power).
Key Challenge: The high SSA of DNP resulted in rapid agglomeration, limiting colloidal stability to approximately 38 minutes at 2 wt.%, underscoring the need for advanced surface functionalization.
Future Research Alignment: The study recommends further investigation into viscosity, surface tension, and combustion residue analysis, areas where high-purity diamond materials are essential for advanced sensor and substrate development.

Technical Specifications

The following table summarizes the critical material properties and performance metrics extracted from the experimental data concerning Diamond Nano Powder (DNP).

Parameter	Value	Unit	Context
Particle Type Analyzed	Diamond Nanopowder (DNP)	N/A	Used as a high-thermal-conductivity additive.
DNP Particle Size Range	3-10	nm	Ultra-fine nano-scale particles.
DNP True Density	3.05-3.30	g/cm³	High density compared to Carbon Fly Ash (CFA).
DNP Specific Surface Area (SSA)	~280	m²/g	High SSA contributes to agglomeration and stability challenges.
Baseline Thermal Conductivity (Jet-A)	0.995	W/m·°C	Thermal conductivity of pure fuel (0 wt.%).
Peak DNP Concentration Tested	2	wt.%	Concentration yielding 2.023% enhancement.
Thermal Conductivity Enhancement (DNP)	2.023	%	Increase achieved at 2 wt.% DNP concentration.
Final Thermal Conductivity (2% DNP)	1.015	W/m·°C	Measured value at peak DNP concentration.
Required Minimum Stability Time	20	minutes	Necessary duration for accurate thermal measurement.
Measured Stability Time (2% DNP)	38	minutes	Stability time before significant phase separation occurred.
Thermal Layer Thickness (Δx)	0.325	mm	Thickness of the fuel sample layer in the Hilton Ltd H470 apparatus.
Heat Flux Voltage Settings	100, 120, 140	V	Used to administer a trio of distinct, constant heat fluxes.

Key Methodologies

The experimental success relied on a hybrid two-step stabilization process and precise thermal measurement techniques.

Surfactant Preparation: A 3 wt.% solution of Span 80 surfactant was prepared in Jet-A fuel using magnetic stirring for 30 minutes.
Particle Dispersion: DNP particles were added to the solution and stirred for an additional 10 minutes to achieve initial homogeneity.
Ultrasonic Stabilization: Samples were sonicated in an Elmasonic S10H ultrasonic bath at 30% power for 45 minutes to prevent particle agglomeration and ensure colloidal stability.
Stability Assessment: Colloidal stability was evaluated using both visual inspection (flashlight) and a custom-built apparatus featuring an IR laser and IR receiver to detect phase separation.
Thermal Conductivity Apparatus: Thermal conductivity (k) was determined using a Hilton Ltd H470 device, applying Fourier’s law of heat conduction.
Heat Flux Control: A known resistance (R) connected to a transformer allowed voltage (V) adjustment (100 V, 120 V, 140 V) to ensure a constant heat rate (Q = V²/R).
Temperature Measurement: Two Type-K thermocouples were used to measure the temperature difference (ΔT) across the thin fuel layer (Δx = 0.325 mm) until thermal equilibrium was reached.

6CCVD Solutions & Capabilities

The research highlights the critical role of diamond materials in advanced thermal management and fuel technology. While the study focused on Nanopowder (DNP), future research, particularly in sensor integration, microfluidics, and high-power thermal dissipation, requires the high-purity, engineered diamond substrates provided by 6CCVD.

Research Requirement / Challenge	6CCVD Solution & Capability	Applicable Materials & Specifications
Extreme Thermal Management: Need for substrates or heat spreaders capable of handling high heat flux in related aerospace/electronic systems.	6CCVD provides MPCVD Single Crystal Diamond (SCD) and Polycrystalline Diamond (PCD) with the highest thermal conductivity available, ideal for integrating high-power components.	Thermal Grade SCD (Type IIa): Thickness up to 500 µm. High-Purity PCD: Wafers up to 125 mm diameter.
Surface Functionalization Studies: Optimizing DNP stability or integrating diamond sensors requires ultra-smooth, clean surfaces for chemical modification.	We offer industry-leading polishing services, ensuring minimal surface defects crucial for reliable chemical bonding and functionalization studies.	Optical Grade SCD: Surface roughness (Ra) < 1 nm. Inch-Size PCD: Ra < 5 nm.
Electrochemical Analysis & Sensing: Proposed residue analysis and future fuel cell/sensor integration require conductive diamond electrodes (Ref [11, 12]).	6CCVD specializes in synthesizing highly conductive Boron-Doped Diamond (BDD) films and wafers, essential for robust electrochemical sensing and analysis in harsh environments.	Heavy Boron-Doped Diamond (BDD): Custom thickness (0.1 µm - 500 µm).
Custom Apparatus Integration: Replicating or extending the experimental setup (e.g., microfluidic channels, custom sensors) requires specific diamond geometries.	We provide full customization services, including precise laser cutting, shaping, and custom substrate thicknesses up to 10 mm.	Custom Dimensions: Plates/wafers up to 125 mm.
Device Integration & Contacting: Future DNP research may involve integrating diamond materials with metal contacts for heating elements or sensors (e.g., Type-K thermocouple integration).	6CCVD offers comprehensive in-house metalization capabilities, ensuring reliable electrical and thermal contacts for complex device architectures.	Metalization Options: Au, Pt, Pd, Ti, W, Cu.

6CCVD is the trusted global supplier for engineers and scientists requiring high-quality, customized MPCVD diamond solutions. Our materials are engineered to meet the stringent demands of advanced thermal, optical, and electrochemical research.

For custom specifications or material consultation, visit 6ccvd.com or contact our engineering team directly.

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Original Source

DOI: https://doi.org/10.11159/ffhmt25.227