Technical articles

Practical Guide to Carbon Nanotube (CNT) Dispersion: Three Key Knobs, SOP, and Selection Roadmap (Tables A–F)

Clarify the “dispersion target”: debundling + stabilization + dispersion grade


Carbon nanotubes (CNTs, including single-walled SWCNTs and multi-walled MWCNTs) naturally tend to form bundles/agglomerates due to strong tube–tube interactions and entanglement arising from their high aspect ratio. In the lab, “dispersion” typically includes two goals:

1. De-agglomeration / debundling: breaking large agglomerates into smaller bundles, or even individual tubes;

2. Stabilization: using dispersants or medium compatibility to prevent re-agglomeration (via steric hindrance, electrostatic repulsion, solvation, etc.).

 

CNTs often exist as agglomerates/entangled networks. The challenge is not simply “stirring,” but debundling the bundles/agglomerates and keeping them stabilized. Common targets can be grouped into three grades:

1. Macroscopic uniformity: visually homogeneous, no rapid settling (suitable for coatings or slurry pre-processing)

2. Stable dispersion: slow settling over days to weeks with good reproducibility (suitable for characterization and formulation screening)

3. Highly debundled / individualized: as many single tubes as possible (common in SWCNT spectroscopy/separation/device research; typically involves centrifugation-based fractionation)

 

1. The “three knobs” of dispersion: medium × dispersant × energy input


1.1 Medium: viscosity is not one-way—it has a dual effect for “ultrasound vs shear”

Lower viscosity favors ultrasonic cavitation and energy transfer; higher viscosity favors shear stress generation but suppresses ultrasonic cavitation—so the medium must be matched to the processing route.

(a) Low viscosity (water, alcohols, most organic solvents): easier to debundle and achieve initial stabilization via probe/cup sonication, bead milling, etc.; however, at high energy density CNTs can be more prone to shortening/defect generation, so manage with pulsing + temperature control + energy logging.

(b) Medium to high viscosity (resins, polymer solutions, high-solids slurries): better suited to three-roll milling, planetary mixing + grinding media, twin-screw compounding/internal mixing, and other high-shear/kneading routes to break agglomerates and achieve uniform distribution; sonication alone is often inefficient due to limited energy delivery.

(c) Melt polymers (highest viscosity): typically processed via twin-screw extrusion or internal mixing; in the lab, reproducibility often improves by first making a “solution pre-dispersion concentrate / masterbatch,” then introducing it into the melt system.

 

1.2 Dispersant: there is no “universal dispersant,” only “matched mechanisms”

Two major stabilization mechanisms are common:

(a) Electrostatic stabilization: ionic surfactants adsorb on CNT surfaces, increasing the magnitude of zeta potential (ζ) and enhancing repulsion. Zeta potential often correlates well with dispersion quality.

(b) Steric stabilization: polymers/block copolymers “wrap/coat” CNT surfaces, providing steric hindrance; commonly used in resin/organic systems.

(c) Note: a frequently cited “demonstration set” of aqueous dispersants/surfactants includes SDS, SDBS, and bile salts (e.g., sodium cholate).

(d) Reminder: increasing salt/ionic strength screens electrostatic repulsion and makes CNTs more prone to aggregation and settling—especially important in biological/buffered systems.

 

1.3 Energy input: sonication is “effective but can damage tubes”—manage by “energy,” not just “time”

(a) Sonication is the most common lab method for debundling. It can indeed improve dispersion, but excessive energy can shorten CNTs, introduce defects, or alter aspect ratio, thereby affecting final performance such as conductivity, mechanical reinforcement, and rheology.

(b) Studies indicate that compared with “how long you sonicate,” the total ultrasonic energy input better determines the extent of breakage/shortening.

 

2. Choosing equipment: work backward from “target + viscosity”


2.1 Low-viscosity systems (most common: water/alcohol/DMF/NMP, etc.)

(a) Probe sonicator: high energy density and high debundling efficiency; more prone to heating and CNT damage, so pulse mode + cooling are needed.

(b) Cup-type sonicator: more stable energy transfer and avoids direct probe contact; some literature recommends it as an alternative route (often emphasizing temperature control and energy delivery).

(c) Bath sonicator: typically lower energy density; better for pre-wetting/initial dispersion. Achieving high debundling often requires longer times and comparability can be poor (large variability across bath units).

 

2.2 Medium-viscosity systems (resins/high-solids slurries)

(a) Three-roll/two-roll mills, planetary mixing + grinding media, etc., are more reliable;

(b) The target is often “macroscopic uniformity + processability,” and “single-tube individualization” is not necessary.

 

2.3 High-viscosity / polymer melts

(a) Twin-screw extrusion, internal mixing, and other “high shear + kneading” equipment is more appropriate; this falls under materials processing. For lab-scale trials, it is often better to prepare a “solution/master dispersion” first, then transfer into melt processing.

 

3. A lab-ready “aqueous CNT dispersion” SOP (general version)


Use the following as a starting condition, then optimize with a small design matrix.

3.1 Materials and equipment

(a) CNT powder (record: SWCNT/MWCNT, diameter/length, functionalization, batch number)

(b) Deionized (DI) water

(c) Dispersant

(d) Magnetic stirring / shear pre-mixing tools

(e) Sonication device (probe or cup-type preferred)

(f) Temperature control (ice bath / recirculating chiller)

(g) Centrifuge (optional, for removing large agglomerates)

 

3.2 Suggested formulation starting points

(a) CNT concentration: start low (e.g., 0.01–0.2 mg/mL range). First establish a working dispersion, then increase solids.

(b) Dispersant concentration: screen within a range that “covers CNT surfaces” but does not introduce excessive foaming or interfere with the intended application.

(c) Why start low? Higher solids promote secondary networks and re-agglomeration; the required sonication energy increases sharply, and it becomes harder to tell whether “debundling is insufficient” or “re-agglomeration is driven by high concentration.”

 

3.3 Procedure

1. Prepare dispersant solution first: after the dispersant fully dissolves in water, measure and record pH and conductivity (or ionic strength/background electrolyte concentration), then add CNTs (to avoid clumping from “powder wrapping”).


2. Slowly add CNT and pre-wet: add while stirring until no powder floats on the surface.


3. Sonicate (pulse mode + temperature control)

(a) Use pulse mode (e.g., on/off cycles) and control temperature throughout to avoid overheating.

(b) Record total input energy, or at minimum record power setting, pulse duty cycle, total time, and volume—because energy input is more comparable than time alone.

(c) If surfactants are present, stable foam may form during sonication. Foam contacting the probe can interfere with/weaken energy transfer. If foam appears, pause sonication and remove it or wait for it to dissipate before continuing. Pulse mode and a longer “off” time can reduce foaming risk.

(d) Long-duration/high-energy probe operation may cause tip erosion (metal particle contamination), which is particularly critical for device/biological experiments. Consider cup-type/indirect sonication, maintain the probe, and include a blank control.


4. Defoaming: foam reduces effective sonication. If needed, stop briefly, stir, or apply vacuum to remove bubbles.


5. Centrifuge to remove agglomerates (optional; recommended for consistency)

(a) Low-to-medium-speed centrifugation can sediment large agglomerates; retain the supernatant as the “usable dispersion.”

(b) When removing large agglomerates by centrifugation, describe conditions using RCF (×g) rather than rpm (more reproducible; rpm depends on rotor radius).


6. Storage and re-check: protect from light, seal tightly, store at 4 °C if needed; record settling after 24 h / 7 d and re-dispersibility.

 

4. “How dispersed is good enough?”

4.1 Visual inspection and settling

(a) Uniform color; no obvious black particles;

(b) Slow settling; consistent supernatant over time.

 

4.2 Spectra / absorbance

(a) Compare UV–Vis(-NIR) absorbance at a fixed dilution factor. Under the same batch/conditions, higher absorbance and smaller drift usually indicate better dispersion (commonly used for SWCNT systems).

(b) Literature often uses absorption/spectral features to evaluate debundling and fractionation.

(c) Scattering/baseline reminder: CNT dispersions often show a combination of “absorption + scattering,” and scattering can raise the baseline. For UV–Vis(-NIR) comparisons, fix cuvette path length and dilution factor, and perform blank subtraction/baseline correction. For SWCNT systems, it is preferable to compare the E11/E22 feature peak groups by peak area, peak shape, or peak-to-baseline ratio, rather than relying only on a single-point absorbance.

 

4.3 Zeta potential / size-related methods

(a) Zeta potential (ζ) can be a quick screening metric for aqueous electrostatically stabilized systems, but correlation weakens for steric-dominated systems; it is best judged together with settling behavior, UV–Vis (peak shape), and centrifugation fractionation results.

(b) Note: CNTs have a high aspect ratio—interpret DLS and similar methods with caution.

 

5. Common issues and countermeasures

1. “More sonication is always better?” Not necessarily. Over-sonication can shorten/damage CNTs and reduce conductivity network formation or mechanical reinforcement. Manage with energy input + temperature control, and judge by the target performance.


2. Sudden deterioration in buffered/salt systems: increased ionic strength accelerates aggregation and settling. Consider switching to steric dispersants, reducing salt, or preparing a master dispersion in DI water and then gradually exchanging the medium.


3. Too much foam: foam “absorbs” sonication energy. Prefer pulse mode, lower surfactant concentration, sonicate in segments, or pre-wet before sonication.


4. Large batch-to-batch variability: record key CNT parameters (diameter, length, functionalization, metal residues) and process parameters (power/duty cycle/volume/temperature/centrifugation conditions) to improve reproducibility.


5. Application performance “below expectation”: residual dispersant may affect interfaces, conductive contacts, or curing. Consider whether washing/exchange/post-treatment is needed.

 

6. Safety and Operating Environment

CNT powders and aerosols may pose potential respiratory hazards. NIOSH has issued recommended exposure limits (RELs) for CNT/CNF (expressed as an 8-h TWA of respirable elemental carbon) and recommends minimizing exposure as much as reasonably achievable.

 

Laboratory recommendations:

1. Perform powder weighing/transfer as much as possible inside a fume hood or under local exhaust ventilation.

2. Wear appropriate respiratory protection, gloves, and safety goggles.

3. During sonication, prevent aerosol escape (cover with film / seal the vessel / use cup-type sonication, etc.).

4. Dispose of CNT-containing waste liquids according to the laboratory’s nanomaterial waste procedures.

 

7. Product Navigation Table | CNT Dispersion and Selection Guide (corresponding to Tables A/B/C/D/F)

 

Target / scenario (dispersion-related)

Recommended route (choose “form” first, then “medium/additives”)

Which table to check first

Recommended Aladdin catalog No. (examples)

Why this choice (key points & cautions)

Getting started / want the fastest “workable dispersion”

Prioritize pre-dispersed slurries/dispersion liquids to validate the process first, then return to powder optimization

D + F

C139955 (aqueous slurry 9–10%); Water: W433885

Pre-dispersed products typically offer better stability and lot-to-lot consistency—ideal for “get it working first, then optimize.” Water quality affects ionic strength and settling; prioritize high-purity water.

Waterborne coatings / water-based conductive slurries / aqueous composite pilot tests

Option A: use aqueous slurry directly; Option B: use short MWCNT powder + aqueous surfactant/dispersing aid

D or A + F

Option A: C139955; Option B: C140997 (short MWCNT) + S432158 (SDS) / S161419 (sodium cholate) + Water W433885

Short tubes disperse more easily and enable low-viscosity processing. SDS/sodium cholate are commonly used aqueous dispersing aids. Note: surfactant residues may affect conductivity and subsequent curing/interface behavior.

Need CNTs that are “easier to disperse / more hydrophilic” (reduced reliance on surfactants)

Prefer functionalized CNTs (-COOH/-OH/-NH/PEG), which are generally easier to handle in polar systems

C + F

C475964 (MWCNT-COOH) / C139828 (MWCNT-OH) / C306012 (MWCNT-NH) / C463008 (SWCNT-PEG)

Functionalization often improves wetting/compatibility in polar media, lowering the dispersion barrier; however, it may also alter conductive networks and interfacial reactions—verify against the intended application.

Biological / aqueous systems (more sensitive to mild dispersion and compatibility)

Mild aqueous surfactants + functionalized CNTs (COOH/PEG) / low-metal SWCNT; prioritize low-salt conditions

C + D + F

C463008 (SWCNT-PEG) / C463015 (SWCNT-COOH) / C139949 (ultra-high-purity SWCNT water dispersion) + S161419 (sodium cholate)

PEG/COOH facilitate aqueous stability and downstream conjugation; ultra-high-purity dispersions suit studies sensitive to metal residues. Salt/buffers can weaken electrostatic stability—recommend establishing a master dispersion in DI water first.

Battery electrodes (PVDF/NMP slurry making)

Prefer NMP slurries or composite conductive additive formulations to reduce powder-dispersion variability

D + F

C139959 (NMP slurry 9–10%) / C409458 (Li-ion CNT composite conductive additive) + M119668 (NMP)

Electrode slurry making emphasizes consistency and conductive network formation. Using NMP slurries/composite additives is more process-friendly. NMP purity and water content can affect reproducibility.

Solvent dispersion / film-forming precursor (DMF system)

Option A: DMF solvent + dispersing aid; Option B: directly use DMF dispersion liquid/slurry

F + D

Option A: D119450 (DMF); Option B: C141006 (SWCNT-DMF dispersion)

DMF is a polar aprotic solvent commonly used for solvent dispersion and film-forming. Control water and impurities to reduce variability.

Devices / transparent conductive films / sensors: need high-performance conductive networks (percolation at low loading)

Prefer high-SSA/long-tube SWCNT powders or high-purity SWCNT dispersions; choose aqueous vs organic based on process

A + D + F

C140995 (high-SSA SWCNT) / C434681 (low-metal SWCNT) / C139949 (water dispersion) / C141008 (toluene dispersion)

SWCNTs more readily form high-performance conductive networks; low-metal/high-purity grades are more device-friendly. Different media (water/toluene) match different film-forming routes.

“Ready-to-use” conductive coatings (don’t want to formulate)

Directly choose finished functional coatings / conductive inks

D

C397868 (conductive coating) / C139977 (transparent antistatic conductive coating) / C487605 (water-based conductive ink)

Finished formulations eliminate dispersion/formulation tuning—ideal for rapid prototyping and process validation. Note: match resin system, viscosity window, and curing method to the substrate.

Resin/epoxy systems: want a low-barrier way to introduce CNT into resin

Prefer pre-dispersed resin formulations, or choose “reactive/compatible” functionalized MWCNTs (NH/OH)

D + C

C196567 (modified epoxy resin with 1–2% CNT); or C306012 (MWCNT-NH) / C139828 (MWCNT-OH)

Pre-dispersion into epoxy significantly lowers agglomeration risk. NH/OH can improve compatibility or react with matrices (epoxy/PU, etc.), but evaluate impacts on curing and electrical performance.

High thermal conductivity / thermal management / environmental durability: prioritize crystallinity and stable heat/electrical conduction

Choose graphitized MWCNT, then follow solvent dispersion or resin compounding depending on the system

A (+ F)

C401691 (graphitized MWCNT)

Graphitization increases crystallinity and stabilizes conductive/thermal performance—useful for thermal management and harsh environments; dispersion and interface still require formulation/process control.

Electrocatalysis / energy storage / higher surface activity: want “more reactive surface chemistry”

Choose doped/special-morphology CNTs; start dispersion trials using a “short-MWCNT route” with a small screening matrix

B (+ F)

C752296 (N-doped CNT) / C736561 (cross-slit CNT)

Doping/special morphologies often change wetting and interfacial behavior; dispersion windows may differ from standard MWCNT—optimize via small DOE screening.

Structured device research: arrays/sheets are not a “dispersion problem,” but “direct integration”

Choose arrays/sheets directly; focus on cleanliness, transfer, and electrode-contact processes

B (+ F for cleaning)

C434680 (MWCNT array) / C476381 (CNT sheet) + I112023 (IPA) / A399740 (acetone)

Arrays/sheets are for device integration and do not require dispersing CNT into liquids; solvents are mainly for substrate cleaning/surface preparation (observe safety and regulatory compliance).

Want to detect/quantify dispersant residues or run methodological controls

Use standard solutions for calibration; if needed, use adsorbents to remove free surfactants/impurities to reduce background

F

S117593 (SDBS standard solution); C284072 (activated carbon)

QC/method development needs standard references. Activated carbon can adsorb and purify, but may also adsorb target components—verify recovery.

 

A | Base CNT Powders

 

Category

Aladdin catalog No.

Product name

CAS No.

Specification / purity

Key features / applications

MWCNT powder (general grade)

C313046

Multi-walled carbon nanotubes

308068-56-6

≥95%, OD: 8–15 nm, Length: ~50 μm, SSA: >140 m²/g

General-purpose MWCNT powder with high specific surface area; suitable for conductive/thermal and reinforced composites, and also for adsorption/interface-related studies.

MWCNT powder (short)

C140997

Short multi-walled carbon nanotubes

308068-56-6

≥98%, OD: 20–30 nm, Length: 0.5–2 μm

Short tubes disperse more easily and support low-viscosity processing; a process-friendly option for uniform conductive fillers in coatings/inks/composites.

Industrial-grade MWCNT powder

C139876

Industrial-grade multi-walled carbon nanotubes

308068-56-6

≥90%, OD: 8–15 nm, Length: 30–50 μm

Better aligned with scale applications and cost balance; suitable for antistatic, conductive composites, coatings/plastics modification, etc.

Graphitized MWCNT powder

C401691

Graphitized multi-walled carbon nanotubes

308068-56-6

≥99.9% metals basis, outer diameter: 10–20 nm, length: 5–30 μm

Graphitization improves crystallinity and stabilizes electrical/thermal conductivity; suitable for high-conductivity/high-thermal-conductivity composites, thermal management, and aging-resistant systems.

SWCNT powder (structural raw material)

C434681

Single-walled carbon nanotubes

308068-56-6

Low metal content

Lower metal residues suit electronics/optoelectronics and precision devices; used in transparent conductive films, sensors, and high-performance conductive networks.

SWCNT powder (high specific surface area)

C140995

High specific surface area single-walled carbon nanotubes

308068-56-6

≥95%, OD: 1–2 nm, Length: 5–30 μm, Floating catalyst

High SSA + long tubes enable percolation at low loading; suitable for high-performance conductive films, sensors, electrodes, and transparent conductive network research.

Few-walled CNT powder

C485346

Carbon nanotubes, few-walled

308068-56-6

≥95%, D×L 2.5–3 nm × 2–6 μm

Between SWCNT and MWCNT in structure; balances performance and cost; suitable for conductive/thermal composites and sensing materials.

Double-walled CNT powder (structural raw material)

C432589

Double-walled carbon nanotubes

308068-56-6

Short; ≤10% metal oxides (TGA)

DWCNTs combine features of SWCNT and MWCNT; suitable for conductive/thermal and reinforced composites, and more favorable for purity/metal-sensitive scenarios.

 

B | Special Structures / Doped Morphologies + Structured Forms (Arrays / Sheets)

 

Category

Aladdin catalog No.

Product name

CAS No.

Specification / purity

Key features / applications

Doped CNT powder

C752296

Nitrogen-doped carbon nanotubes

≥95%, OD: 30–50 nm, Length: 10–30 μm

N-doping tunes electrical properties and surface chemistry activity; used for electrocatalyst supports, energy-storage electrodes, sensors, and interfacial functionalization research.

Special-morphology CNT powder

C736561

Cross-slit carbon nanotubes

308068-56-6

≥95%, Diameter: 20–40 nm, Length: 5–15 μm

“Cross/slit” morphology promotes multi-point junctions and robust networking; suitable for stable conductive pathways, reinforced composites, and EM absorption/conductive application exploration.

Aligned/array/structured CNT

C434680

Multi-walled carbon nanotube array

308068-56-6

Vertically aligned on silicon substrate

Vertical arrays support field emission, microelectrodes, interfacial electrochemistry, and device-oriented studies.

Aligned/sheet/film CNT

C476381

Carbon nanotube sheet

308068-56-6

Aligned, size × thickness 50 mm × 50 mm × 1–5 μm

Aligned sheets simplify device integration; used for conductive films, flexible electrodes, sensing/heating films, and interface research.

 

C | Functionalized CNTs

 

Category

Aladdin catalog No.

Product name

CAS No.

Specification / purity

Key features / applications

Functionalized CNT (carboxylic acid)

C475964

Carbon nanotubes, multi-walled, carboxylic acid functionalized

Thin; functionalization range: >8% carboxyl groups, avg. diameter × L 9.5 nm × 1.5 μm

-COOH improves dispersion in polar media and strengthens CNT–matrix interfacial bonding; suitable for aqueous/polar solvent dispersion, composite bonding enhancement, and further conjugation/modification.

Functionalized MWCNT (hydroxyl)

C139828

Hydroxylated multi-walled carbon nanotubes

308068-56-6

≥95%, -OH Functionalized, OD: 20–30 nm, Length: 10–30 μm

-OH improves dispersion and interfacial interactions in polar systems; used in resins/aqueous systems, surface modification, and composite reinforcement.

Functionalized MWCNT (amine)

C306012

Aminated multi-walled carbon nanotubes

308068-56-6

≥95%, outer diameter: 8–15 nm, length: ~50 μm

-NH improves reactivity/compatibility with epoxy/PU matrices; suitable for composite interface enhancement and downstream coupling/modification.

Functionalized SWCNT (carboxylic acid)

C463015

Carbon nanotubes, single-walled, carboxylic acid functionalized

≥90% carbon basis, D×L 4–5 nm × 0.5–1.5 μm, bundle dimensions

-COOH supports conjugation and dispersion in water/polar media; used for bioconjugation, composite interface strengthening, and electrode/sensor surface chemistry.

Functionalized SWCNT (PEG)

C463008

Carbon nanotubes, single-walled, poly(ethylene glycol) functionalized

≥80% carbon basis, D×L 4–5 nm × 0.5–0.6 μm, bundle dimensions

PEGylation improves dispersion stability and favors hydrophilicity/biocompatibility; suitable for aqueous processing, bio-related systems, and anti-aggregation applications.

 

D | Dispersions / Slurries / Inks + Application Formulations (Coatings / Batteries / Resins) + Composite Slurries

 

Category

Aladdin catalog No.

Product name

CAS No.

Specification / purity

Key features / applications

Dispersion/slurry (aqueous)

C139955

Carbon nanotube aqueous slurry

308068-56-6

9–10 wt% in water

High-solids water-based slurry for coating/slurry processing; used in waterborne coatings, conductive slurries, electrode coating, and aqueous composite workflows.

Dispersion/slurry (NMP)

C139959

Carbon nanotube NMP slurry

308068-56-6

9–10 wt% in NMP

NMP systems are common for battery electrode slurries; compatible with PVDF systems to build conductive networks.

DMF dispersion liquid

C141006

Mixed Plasma SWCNT DMF dispersion

≥98%

Pre-dispersed SWCNT in DMF (plasma-treated, mixed type): suitable for solvent dispersion and film-forming precursor liquids; avoids powder wetting/debundling steps and improves reproducibility. Used for vacuum filtration/coating/spin-coating and other film-forming processes. Recommend controlling water/impurities; gently mix and dilute as needed before use.

Ultra-high-purity SWCNT (aqueous dispersion)

C139949

Ultra-high-purity SWCNT water dispersion

308068-56-6

0.2 wt% in water

Ultra-high-purity SWCNT aqueous dispersion; suitable for device/sensor/optoelectronic research sensitive to metal residues and for building advanced conductive networks.

Semiconducting SWCNT dispersion (toluene)

C141008

Semiconducting HiPCO SWCNT toluene dispersion

≥99.9%

HiPCO-derived semiconducting SWCNT; suitable for high-mobility films, device studies, and film formation via organic-solvent processing.

Conductive ink (water-based, SWCNT)

C487605

Carbon nanotubes, single-walled, water-based conductive ink, SWCNT 0.2 mg/mL

Ready-to-use aqueous conductive ink; suitable for inkjet/screen printing/coating to fabricate flexible electrodes, sensor traces, and rapid prototypes.

Functional coating (conductive formulation)

C397868

CNT conductive coating

Resistivity (Ω·cm) 0.1

Low-resistivity conductive coating formulation; used for antistatic, shielding, conductive primers/functional coatings.

Functional coating (transparent antistatic conductive)

C139977

CNT transparent antistatic conductive coating

Transparent + antistatic conductivity; for displays/optical windows/transparent substrates requiring both transmittance and surface resistivity.

Battery conductive additive / network (formulation)

C409458

CNT composite conductive additive for Li-ion batteries

308068-56-6

d50 50–80 nm, tube length 10–15 μm, SSA 80 m²/g, pH < 9

Designed for Li-ion electrode conductive network construction; commonly used to reduce internal resistance and improve rate/cycling (often compounded with carbon black/graphite, etc.).

Resin/matrix composite (formulation)

C196567

CNT-modified epoxy resin

CNT content: 1–2 wt%

Pre-dispersed in epoxy to reduce agglomeration barrier; used to improve conductivity/thermal conductivity and mechanical performance; convenient for direct formulation and curing applications.

Graphene/CNT composite slurry

G139808

Industrial-grade nano graphene platelet + CNT composite aqueous slurry

7782-42-5

GNP + CNTs: 1–5 wt%, GNP:CNTs = 1:1, dispersant: 0.2–1.0 wt%

GNP + CNT synergistically build conductive/thermal networks; aqueous slurry suits coating, slurry systems, conductive coatings, and composite formulations.

 

Table F | Representative Chemicals for CNT Dispersion and Pre-treatment (Selection Guide)

 

Category

CAS No.

Aladdin catalog No.

Product name

Specification / purity

Key features / applications

Aqueous medium (solvent/dispersion medium)

7732-18-5

W433885

Water

MS grade, UltraPureChrom™, UHPLC grade

High-purity water reduces ionic/organic background; suitable for preparing CNT aqueous dispersions, surfactant solutions, and analytical/testing solvents.

Surfactant (anionic; common for aqueous CNT dispersion)

151-21-3

S432158

Sodium dodecyl sulfate (SDS)

For electrophoresis, anionic

Classic anionic surfactant; stabilizes CNT aqueous dispersions via micelles/adsorption. Electrophoresis grade is often used when impurities matter more (remove free surfactant thoroughly to avoid impacting conductivity/background).

Surfactant/dispersant (anionic; formulation dispersion)

69669-44-9

S161241

Sodium dodecylbenzenesulfonate (soft type)

≥95% (T)

Anionic aryl sulfonate surfactant; used in aqueous CNT dispersion and coatings/slurry formulations (“soft type” is often associated with processing/handling characteristics; validate against application targets).

Surfactant/dispersant (anionic; standard for quantification)

25155-30-0

S117593

Sodium dodecylbenzenesulfonate standard solution (SDBS)

Analytical standard, 1000 μg/mL in water

Used for quantitative calibration of SDBS-related methods; suitable for analytical controls/QC on dispersant residues and formulation concentrations.

Bio-surfactant (bile salt; mild dispersion)

361-09-1

S161419

Sodium cholate

Moligand™, ≥98%

Mild bile-salt surfactant; commonly used to stabilize CNT dispersion under biological/aqueous conditions; may be preferable for protein/cell-sensitive systems (still evaluate residue effects).

Polar aprotic solvent (solvent dispersion/film-forming)

68-12-2

D119450

N,N-Dimethylformamide (DMF)

Anhydrous, ≥99.8%

Strong polar solvent; commonly used for CNT dispersion in organic systems and precursor solutions compatible with polymers/resins (anhydrous grade helps reduce variability in moisture-sensitive systems).

Polar aprotic solvent (electrode slurry/coating systems)

872-50-4

M119668

N-Methyl-2-pyrrolidone (NMP)

Anhydrous, ≥99.5%

Common solvent for electrode slurries (typical for PVDF systems); suitable for dispersing CNT conductive additives and battery electrode coating processes (anhydrous grade supports consistency).

Organic solvent (alcohol; cleaning/dispersion aid)

67-63-0

I112023

Isopropanol (IPA)

Prep chromatography grade, ≥99.8%

Fast-evaporating and good wetting; used for cleaning and solvent exchange, and can be used for CNT alcohol-based slurries/film precursors (miscible with water for easy transitions).

Organic solvent (alcohol; cleaning/dispersion aid)

64-17-5

E111989

Ethanol

AR grade, water ≤0.3%

Common alcohol solvent; used for cleaning, solvent exchange, and alcohol–water dispersion/coating (water-content spec helps reproducibility).

Organic solvent (cleaning/exchange/pre-treatment; dispersion aid)

67-64-1

A399740

Acetone (regulated precursor)

Histology grade, ≥99.5%

Low-boiling strong solvent; commonly used for degreasing/decontaminating labware/substrates, pre-cleaning, and solvent exchange (observe flammability and regulatory compliance).

Adsorbent (purification/removal of impurities)

7440-44-0

C284072

Activated carbon

For APIs

High-SSA adsorbent; used for solution purification, decolorization, and removal of organic impurities; can also remove some surfactants/impurities to reduce background.

 

Note: The above are representative Aladdin products. For additional specifications, please refer to the product list at the end of the article or search by product name/CAS on the Aladdin website.

 

Categories: Technical articles
Explore topics: Carbon Nanotube

Da — when not otherwise indicated, molecular weight units are daltons.   Mw — weight-average molecular weight.   Mn — number-average molecular weight.

Products are supplied for research and development use only. Not for use in humans, animals, diagnosis, or therapy.

Cite this article

Aladdin Scientific. "Practical Guide to Carbon Nanotube (CNT) Dispersion: Three Key Knobs, SOP, and Selection Roadmap (Tables A–F)" Aladdin Knowledge Base, updated Jan 18, 2026. https://www.aladdinsci.com/us_en/faqs/practical-guide-to-carbon-nanotube-cnt-dispersion-en.html
Was this article helpful? Yes No 1 out 2 found this helpful

Shall we send you a message when we have discounts available?

Remind me later

Thank you! Please check your email inbox to confirm.

Oops! Notifications are disabled.