The Core Balance in Conductive Inks: Percolation Networks, Printability, and Mechanical Reliability

Introduction

A typical phenomenon is often observed in conductive ink experiments:

When common insulating resins, elastomers, or binders are used as the matrix, the continuous polymer phase usually lacks an effective pathway for electron transport. After a small amount of graphene, carbon nanotubes, or carbon black is added, the material still remains close to insulating. As the conductive filler content continues to increase, the resistance suddenly drops sharply near a certain loading level, and the material begins to show clear electrical conductivity. However, when the filler content continues to increase further, more problems also appear: the ink viscosity rises, ink delivery becomes more difficult, the risk of agglomeration increases, nozzles are more likely to clog, dimensional changes caused by drying, curing, or solvent evaporation become more obvious, the continuous polymer phase may be disrupted, the material may become brittle, internal stress in the printed pattern or structure may increase, and cracking, delamination, or resistance drift may occur after bending.

This shows that the core issue in conductive inks is not “the more filler, the better.” Instead, three questions must be answered at the same time:

1. Has a conductive network formed?

2. Can the ink still be printed stably?

3. Does the formed material have sufficient mechanical reliability?

Together, these three questions form the triangular balance in conductive ink design.

Balance target	Core question	Main evaluation indicators
Conductive network	Has the conductive filler formed an effective pathway that runs through the whole material?	Resistance, sheet resistance, electrical conductivity, multi-point resistance
Printability	Can the ink flow, deposit, form a film, or be shaped stably?	Viscosity, rheological behavior, nozzle clogging, line width, film thickness, edge quality
Mechanical and service reliability	Can the pattern or structure withstand post-treatment and actual use?	Shrinkage, adhesion, cracks, resistance change after bending, tensile or compressive stability

Conductive ink experiments should not only pursue the “lowest resistance.” A reliable formulation should meet the requirements for conductivity, printing, shaping, post-treatment, and service stability at the same time.

1. Why does an insulating polymer become conductive after conductive fillers are added?

An insulating polymer itself lacks a continuous pathway for charge transport. When only a small amount of conductive filler is added, the fillers are far apart from one another, and most of them remain isolated. Current cannot travel from one end of the material to the other. When the filler content increases to a certain level, the fillers begin to contact one another, or the spacing between them becomes small enough to allow effective electron transport. At this point, a conductive pathway that runs through the whole material forms inside the material. This critical state is called electrical percolation.

From the perspective of microstructure, the conductivity transition usually goes through three stages:

Stage 1: Insufficient filler.

The fillers are isolated from one another, the overall material remains close to insulating, and the resistance is very high.

Stage 2: Near the percolation threshold.

Local conductive pathways begin to connect. The resistance becomes highly sensitive to filler content, dispersion state, and processing conditions, and a rapid drop in resistance is often observed.

Stage 3: Above the percolation threshold.

A continuous network forms inside the material, electrical conductivity increases significantly, and the decline in resistance tends to level off. The material “suddenly becoming conductive” does not mean that the chemical nature of the polymer has suddenly changed. It means that the conductive fillers inside the material have changed from an isolated state to a connected state.

2. Why is the percolation threshold not a fixed number?

The percolation threshold refers to the critical filler content required for a material to change from an insulating state to a clearly conductive state. It is not a fixed value determined only by the filler. Instead, it is jointly affected by filler morphology, size, dispersion state, polymer matrix, and processing method.

Reviews on carbon nanotube/polymer composites have shown that the type of carbon nanotube, treatment method, polymer type, and dispersion method all affect the percolation threshold, conductive behavior, and maximum electrical conductivity. Modeling studies on graphite nanoplatelet-reinforced polymers have also shown that platelet thickness, diameter, and three-dimensional random distribution can affect the percolation threshold.

In conductive inks, the percolation threshold must be understood in relation to processing conditions. At the same filler content, ultrasonication, shear mixing, ball milling, extrusion, drying, annealing, and compaction may all change the spacing, orientation, and contact state between fillers, thereby changing the final resistance. Therefore, in experiments, one should not simply say that “a certain filler will definitely become conductive at a certain loading.” Instead, the key question is whether a conductive network has truly formed under the current resin, solvent, dispersion method, printing method, and post-treatment conditions.

It should also be noted that filler content in literature and product formulations may be expressed as either mass fraction or volume fraction. Different fillers and different polymer systems cannot be compared only by weight percentage. Density, platelet packing, effective volume fraction, and dispersion state should also be considered.

3. How does the percolation network determine the electrical performance of conductive composites?

A percolation network is a continuous conductive pathway formed by conductive fillers in an insulating matrix. It determines whether current can pass through the entire material and whether the resistance remains stable. In graphene, carbon nanotube, and carbon black composite systems, current transport mainly depends on two types of pathways:

1) Direct contact pathways.

The fillers are in direct contact with one another, and current is transported through contact points. Such pathways are usually favorable for reducing resistance, but they are also easily affected by filler dispersion, compaction degree, and interfacial state.

2) Short-distance tunneling and interface-assisted transport pathways.

The fillers are not in complete direct contact but are separated by a very thin polymer layer, dispersant layer, or interfacial layer. When the spacing is small enough and the interfacial resistance is acceptable, electron transport may still occur. For carbon nanotube composites, simulation studies have shown that tunneling resistance may play an important role in the overall electrical conductivity, especially when filler contact is not completely ideal.

The percolation network affects the following results:

1. Electrical conductivity: the more continuous the network, the higher the electrical conductivity usually is.

2. Resistance uniformity: the more uniform the network, the smaller the resistance fluctuation at different positions.

3. Bending reliability: the better the network can withstand deformation, the more stable the resistance remains after bending.

4. Batch-to-batch reproducibility: the more controllable the network formation is, the smaller the differences between repeated experiments.

5. Sensor response: the closer the network is to the critical state, the more sensitive it is to small structural changes.

Near the percolation threshold, the resistance of the material is highly sensitive to small structural changes. This state is suitable for strain, pressure, or deformation sensors, because external force can change the conductive pathways and produce a clear resistance change. However, if the target is a stable electrode, flexible conductor, or conductive interconnect, being too close to the percolation threshold may instead lead to resistance drift, unstable cycling, and batch-to-batch differences.

4. What factors determine whether a conductive network can form?

A conductive network is not determined by filler content alone. At the same content, different filler morphologies, sizes, orientations, and dispersion states can lead to different electrical results.

4.1 Key variables affecting conductive network formation and processing risks

Variable	Effect on the conductive network	Risk to printing or shaping	Priority observations in experiments
Filler content	Determines whether there is an opportunity to form a through-network	Excessively high content increases viscosity, clogging, and embrittlement risks	Resistance drop region, continuous ink delivery, cracking
Aspect ratio or platelet diameter-to-thickness ratio	High-aspect-ratio carbon nanotubes and high-diameter-to-thickness-ratio platelets favor network connection at low loading	Risks of entanglement, agglomeration, orientation, and sedimentation increase	Dispersion morphology, viscosity change, network uniformity
Platelet size or tube length	Under controlled dispersion and compatible nozzle conditions, larger dimensions help bridge longer distances	Excessive size may clog the nozzle or produce rough lines	Nozzle matching, line edge quality, sedimentation stability
Orientation	Can improve conductivity in a specific direction	Through-thickness or interlayer conductivity may be insufficient	In-plane resistance, through-thickness resistance, interlayer connection
Dispersion state	Determines whether the network is uniformly connected or locally agglomerated	Agglomeration causes clogging; excessive insulating dispersant increases interfacial resistance	Multi-point resistance, microscopic morphology, batch reproducibility
Polymer matrix	Affects filler distribution, interfacial interactions, and film-forming strength	Excessive binder may hinder filler contact	Resistance, adhesion, flexibility
Post-treatment conditions	Can improve filler contact and remove residual solvent or dispersant	Excessively high temperature or excessive shrinkage may cause cracking	Resistance before and after post-treatment, cracks, adhesion

One-dimensional carbon nanotubes and two-dimensional graphene platelets usually form conductive networks more easily than ordinary particulate fillers, because they have high aspect ratios or high platelet diameter-to-thickness ratios and can bridge longer distances at lower loading levels. However, this does not mean that larger dimensions are always better. Larger graphene platelets or longer carbon nanotubes help build long-distance connections, but they also increase the risks of sedimentation, entanglement, agglomeration, and clogging.

Dispersion state is equally important. Severe agglomeration can cause local conductivity but poor overall uniformity, leading to nozzle clogging, rough lines, and resistance fluctuation. Conversely, excessive insulating dispersant or overly thick polymer coating may improve apparent dispersion stability, but it can increase the distance between fillers and the interfacial resistance, resulting in higher resistance.

What conductive inks need is a dispersion state that avoids large agglomerates while still preserving opportunities for filler-to-filler contact.

5. Why is more conductive filler not always better?

Increasing conductive filler content usually increases the number of conductive pathways, but beyond a certain range, ink processing and material reliability deteriorate rapidly. The main costs of high filler loading include:

1) Increased viscosity.

Interactions between solid particles become stronger, ink delivery becomes difficult, and printing pressure increases.

2) Nozzle clogging.

More agglomerates form, and excessively large platelets or tube bundles may cause broken lines, clogged nozzles, or jet misdirection.

3) Narrower printing window.

Flow, deposition, drying, and curing become harder to control at the same time, and line-width stability decreases.

4) Greater dimensional and pore-structure changes.

In some solvent-based or high-solid-content systems, the solvent ratio may need to be adjusted to maintain printability. Drying, curing, or solvent evaporation may also cause shrinkage, warping, or pore-structure changes.

5) Material embrittlement.

The continuous polymer phase is interrupted by excessive filler, making the material more prone to cracking during bending or stretching.

6) Reduced adhesion.

Internal stress and interfacial defects increase, which may cause delamination, warping, or peeling.

5.1 Case study: PLA/multi-walled carbon nanotube 3D-printable composites

Multi-walled carbon nanotube content	Electrical performance	Mechanical and dimensional performance
5 wt%	Electrical conductivity of approximately 39.7 S/m	Elongation at break is significantly lower than that of neat PLA
10 wt%	Electrical conductivity continues to increase	Tensile strength remains higher than that of neat PLA
20 wt%	Electrical conductivity of approximately 1206 S/m	Elongation at break decreases sharply, tensile strength is lower than that of neat PLA, and maximum diameter shrinkage is approximately 52%

This case shows that when the multi-walled carbon nanotube content increases from 5 wt% to 20 wt%, electrical conductivity increases significantly, mainly because interactions between fillers increase and the number of conductive pathways increases. The article also points out that further increasing the multi-walled carbon nanotube content may further improve electrical conductivity, but the increased viscosity would make the printing process significantly more difficult. This case illustrates that increasing filler content can improve conductivity, but it may also sacrifice printing stability, dimensional accuracy, and mechanical toughness.

6. How should the triangular balance among conductivity, printability, and mechanical performance be understood?

In conductive ink experiments, many failures are not caused by one indicator being completely unacceptable. Instead, one indicator is over-optimized and disrupts the others.

For example, increasing filler content can improve electrical conductivity, but it may also increase viscosity, increase clogging, and make the material brittle. Reducing viscosity can make printing smoother, but if the solid content decreases, the film may become thinner and the resistance may increase. Increasing the polymer binder can improve adhesion and film formation, but it may also reduce filler contact and decrease conductivity.

6.1 Network state and formulation focus for different application targets

Application target	Required network state	Formulation and process focus	Issues to avoid
Stable conductive electrode	Above the percolation threshold, with a relatively sufficient network	Reduce resistance and improve film uniformity and adhesion	Resistance drift caused by being too close to the percolation region
Flexible conductor	A sufficient network that can also withstand bending	Control filler contact, binder flexibility, and substrate adhesion simultaneously	Brittle film, cracking after bending
Strain sensor	Close to the percolation region, with resistance sensitive to deformation	Control the critical network state and cycling response	Excessive resistance drift, irreversible cycling behavior
Large-area conductive coating	Uniform network and stable film thickness	Control dispersion, coating stability, and drying process	Local agglomeration, uneven film thickness
Three-dimensional conductive scaffold	Network running through the whole structure, with interlayer connection	Control shaping stability, interlayer connection, and shrinkage	Collapse, shrinkage, interlayer separation
Electromagnetic shielding material	High filler connectivity and sufficient thickness	Control continuous conductive network, pore structure, and thickness	Insufficient filler connectivity, insufficient thickness, pore structure interrupting conductive pathways
Microelectrode	Controllable line width, film thickness, and low resistance at the same time	Nozzle matching, edge quality, and post-treatment conditions	Clogging, edge spreading, cracking after post-treatment

Therefore, experimental evaluation should not only ask, “Which formulation has the highest electrical conductivity?” It should also ask:

1. Can this formulation be printed stably?

2. Are the dimensions of the pattern or structure controllable?

3. Does cracking or delamination occur after post-treatment?

4. Does the resistance remain stable after bending, stretching, or compression?

5. If the material batch is changed or the experiment is repeated, are the results still similar?

A truly valuable conductive ink is not necessarily the formulation with the highest electrical conductivity. It is the formulation that can simultaneously meet the requirements for conductivity, printing, shaping, post-treatment, and service reliability.

7. How should an experimental matrix be designed for conductive ink studies?

Conductive ink experiments should not only follow the approach of “gradually increasing filler content and then measuring resistance.” A more effective method is to divide the experiment into three stages: first identify the percolation region, then determine the printable range, and finally verify reliability.

Printability also cannot be judged by viscosity alone. Different printing methods require attention to different indicators. Extrusion or direct ink writing systems should focus on shear thinning, yield stress, and thixotropic recovery. Inkjet systems should focus on surface tension and the matching between particle or agglomerate size and nozzle size. Doctor blading, screen printing, and gravure printing also require attention to leveling, edge retention, and drying rate. In graphene ink development, solid content, viscosity, surface tension, and evaporation dynamics all need to be adjusted according to the specific printing technology.

7.1 Conductive ink experimental matrix: From the percolation region to application reliability

Experimental stage	Purpose	Core variables	Required measurements	Criteria for moving forward
Identify the percolation region	Determine whether the filler begins to form a conductive network	Filler content, filler type, dispersion method, binder ratio	Resistance, sheet resistance, electrical conductivity, multi-point resistance	A clear resistance drop appears, and reproducibility is acceptable
Identify the printable range	Determine whether the ink can be deposited or shaped stably	Viscosity, rheological behavior, solid content, nozzle size, pressure, speed, drying conditions	Continuous ink delivery, clogging, line width, film thickness, edge quality	Continuous printing is possible, and dimensional and film-thickness fluctuations are controllable
Verify film or structure quality	Determine whether the pattern or structure is complete	Drying rate, substrate temperature, number of layers, film thickness, solvent ratio	Surface morphology, pores, cracks, shrinkage, adhesion, interlayer bonding	The pattern does not crack or delaminate, and dimensional changes are predictable
Verify post-treatment compatibility	Determine whether annealing, washing, or compaction improves the network	Temperature, time, atmosphere, washing conditions, compaction conditions	Resistance before and after post-treatment, cracks, adhesion, film-thickness change	Resistance decreases or remains stable, and the structure is not damaged
Verify service reliability	Determine whether the material is suitable for the target application	Bending, stretching, compression, cycling, storage conditions	Resistance change after bending, cycling drift, mechanical properties, storage stability	Performance changes remain within the allowable range for the application

8. How can one judge whether a formulation is worth further optimization?

In conductive ink experiments, some formulations have high electrical conductivity but are not suitable for further development. Other formulations may not have the highest conductivity, but they are closer to the requirements of real applications.

8.1 Evaluation of whether a conductive ink formulation is worth further optimization

Evaluation direction	Specific observation	Recommended action
Worth further optimization	Resistance is close to the target, and printing is stable	Continue fine-tuning filler content, binder, and post-treatment conditions
Worth further optimization	Electrical conductivity is relatively high, while viscosity remains controllable	Further optimize solid content, solvent ratio, and printing parameters
Worth further optimization	Good flexibility, with stable resistance after bending	Suitable for continued validation in flexible electronics or sensor applications
Worth further optimization	Low shrinkage and good dimensional reproducibility	Suitable for structured devices or multilayer pattern development
Worth further optimization	Stable performance after post-treatment	Indicates that the process conditions have a basis for further scale-up
Worth further optimization	Small batch-to-batch variation	Indicates that the dispersion and preparation process is reproducible
Not suitable for continued development along the original formulation direction	High electrical conductivity but frequent clogging	The processing window is too narrow; prioritize adjustment of filler size, dispersion, and nozzle matching
Not suitable for continued development along the original formulation direction	Low initial resistance but failure after bending	Flexible reliability is insufficient; rebalance filler and binder
Not suitable for continued development along the original formulation direction	Severe shrinkage after printing	Dimensions are not controllable; adjust solid content, solvent, and drying process
Not suitable for continued development along the original formulation direction	High filler loading causes obvious embrittlement	Mechanical performance is not suitable for use; reduce filler content or change the matrix
Not suitable for continued development along the original formulation direction	Large batch-to-batch differences	Dispersion and preparation process are not controllable and are not suitable for direct scale-up
Not suitable for continued development along the original formulation direction	Pattern cracks or delaminates after post-treatment	The formulation is incompatible with the post-treatment conditions

9. Product Table Navigation for Conductive Ink Percolation Networks, Printability, and Mechanical Reliability

Research or experimental goal	Recommended table to consult first	Why start with this table	Recommended related tables	Navigation notes
Directly carry out conductive patterning experiments by inkjet printing, screen printing, gravure printing, spin coating, spray coating, or 3D printing	Table 1	Table 1 focuses on ready-to-use graphene inks and directly printable systems, allowing initial verification of ink delivery, pattern transfer, film formation, and resistance changes after post-treatment	Tables 2 and 3	First use ready-to-use inks to confirm whether the target process is feasible, then return to slurry and powder-level formulation adjustment based on clogging, line width, film thickness, resistance, or cracking issues
Compare the effects of different printing methods on conductive network formation	Table 1	Table 1 covers inkjet printing, screen printing, gravure printing, flexographic printing, spin coating, spray coating, and 3D printing, making it useful for comparing how process conditions affect pattern quality and resistance stability	Table 2	Focus on viscosity, solid content, drying process, film thickness, and post-treatment method; platelet packing and conductive pathways formed under different processes are not the same
Develop a graphene conductive ink formulation from scratch	Table 2	Table 2 includes graphene slurries, dispersions, and composite slurries, which can be used to build an initial formulation around solvent system, dispersant content, graphene content, and dispersion stability	Tables 3 and 4	First use slurries or dispersions to establish a processable system, then select platelet powders, reduced graphene oxide, or functionalized materials for further optimization based on resistance and film quality
Study the effect of dispersant content on conductive contact and resistance	Table 2	Multiple slurries in Table 2 specify graphene content and dispersant content, making them suitable for comparing the balance between dispersion stability and platelet contact	Table 4	Dispersants help stabilize the system but may also increase the spacing between platelets; functionalized graphene can be considered to evaluate whether interfacial modification can reduce reliance on dispersants alone
Study the effects of graphene platelet diameter, thickness, and specific surface area on the percolation threshold	Table 3	Table 3 focuses on powder, microsheet, and nanoplatelet conductive fillers, with specifications including platelet size, thickness, specific surface area, or conductivity	Table 2	First compare how different platelet structures affect conductive network formation, then verify their dispersion, viscosity, and film-forming behavior in actual ink systems through slurry formulations
Determine whether large-diameter graphene is suitable for the target printing method	Table 3	Table 3 includes large-diameter chemically reduced graphene and large-diameter thin-layer graphene powder, which can be used to evaluate long-distance bridging and processing risks	Tables 1 and 2	Large-diameter platelets help build continuous pathways, but sedimentation, line roughness, nozzle clogging, and film uniformity must also be examined
Build a synergistic conductive network from graphene platelets and carbon nanotubes	Table 2	Table 2 includes an aqueous composite slurry of graphene platelets and carbon nanotubes, which can be directly used to study platelet bridging and tubular bridging	Table 6	If comparison of tube length, tube diameter, hydroxylation, and graphitization effects on the network is needed, the multi-walled carbon nanotube products in Table 6 can be used together
Study dispersion stability, wetting, and resistance changes in aqueous conductive inks	Table 2	Table 2 includes aqueous graphene slurries, aqueous dispersions, and surfactant-containing dispersion systems, making it suitable for initial screening of aqueous formulations	Tables 4 and 6	Aqueous systems require simultaneous attention to dispersion stability, substrate wetting, drying shrinkage, and the influence of residues on conductive contact
Build a conductive network through a graphene oxide film-forming and post-reduction route	Table 4	Table 4 includes graphene oxide, reduced graphene oxide, and sulfonated reduced graphene oxide, making it suitable for studying aqueous dispersion, film formation, and post-reduction processes	Tables 2 and 3	Graphene oxide facilitates aqueous dispersion and film formation, but final conductivity must be evaluated together with reduction degree, platelet contact, and residual oxygen-containing groups
Improve polymer matrix compatibility, substrate adhesion, and bending reliability	Table 4	Table 4 includes silane-modified, carboxylated, and sulfonated reduced graphene oxide, which can be used for interfacial bonding and dispersion-control studies	Tables 5 and 6	Interfacial modification can help improve adhesion and composite stability, but it is also necessary to evaluate whether platelet contact is hindered and whether resistance drifts after bending
Study three-dimensional conductive structures, interlayer connectivity, and compression stability	Table 5	Table 5 includes 3D graphene and graphene nanoplatelet/polypropylene pellets, which are suitable for understanding through-conductive networks from the perspective of structural materials	Tables 1 and 6	Three-dimensional conductive structures require attention to shaping stability, interlayer connection, resistance changes after compression or bending, and the influence of the polymer matrix on mechanical performance
Reproduce experimental cases or study the triangular balance in polymer conductive composites	Table 6	Table 6 includes multi-walled carbon nanotubes, polylactic acid, and carbon reference fillers, corresponding to the relationship among filler content, percolation network, printability, and mechanical properties	Tables 2 and 3	Suitable for comparative experiments around polymer matrix, carbon nanotube aspect ratio, graphene platelets, and carbon black particles
Compare graphene, carbon nanotubes, and carbon black as conductive fillers	Table 6	Table 6 provides tubular, particulate, and mesoporous carbon materials, which can serve as references for graphene systems	Table 3	Starting from filler morphology, compare platelet, tubular, and particulate fillers in terms of percolation threshold, viscosity, clogging risk, and mechanical impact
Troubleshoot high resistance, clogging, cracking, or batch-to-batch variation in conductive inks	Table 2	Table 2 allows formulation problems to be examined from the perspectives of slurry concentration, dispersant, solvent, and dispersion stability	Tables 1, 3, and 4	High resistance can be checked through platelet contact and dispersant residue; clogging can be checked through platelet size, agglomeration, and nozzle matching; cracking can be checked through solid content, binder system, post-treatment, and interfacial bonding
Establish a complete experimental pathway from material screening to application validation	Table 1	Table 1 can first confirm the target printing method and application scenario, avoiding excessive raw-material combination screening at the beginning	Tables 2, 3, 4, 5, and 6	First use ready-to-use inks to verify process feasibility, then use slurries, powders, functionalized materials, structural materials, and reference carbon fillers to gradually identify the limiting factors for conductivity, printing, and mechanical reliability

Table 1 | Ready-to-Use Graphene Inks and Direct Printing Systems

Category	CAS No.	Aladdin Cat. No.	Name	Specification or Purity	Product Features and Applications
3D-printing graphene ink	—	D487607	3D printing graphene ink	—	Used for 3D-printed conductive structures; suitable for evaluating extrusion continuity, interlayer connectivity, shaping shrinkage, and structural resistance stability
Spin-coating/spray-coating post-treatment ink	—	G485796	Graphene ink for spin/spray coating photonically annealable	For spin coating, spray coating, and photonic annealing	Used in spin coating, spray coating, and photonic annealing processes; suitable for evaluating how post-treatment affects platelet contact, film resistance, and cracking risk
High-solid-content graphene ink	—	G485891	Graphene	Ink, solid content 40%, 100 g, viscosity 5.5 Pa·s	Clear information on solid content and viscosity; suitable for studying the balance among solid content, flowability, ink delivery stability, and conductive network formation
Aqueous inkjet graphene ink	—	G477895	Graphene ink in water	Inkjet printing	Used in inkjet printing systems; suitable for evaluating jetting stability, nozzle matching, line-width control, and film resistance
Multi-process aqueous printing ink	—	G478442	Graphene ink in water	Flexographic/gravure/screen printing	Suitable for comparing deposition stability, film-thickness control, drying process, and conductive continuity under different printing methods
Screen-printing graphene ink	—	G485792	Graphene ink	For screen printing; contains ethyl cellulose and terpineol; screen-printable	Used for screen-printed conductive patterns; suitable for evaluating how binder, solvent evaporation, film thickness, and platelet contact affect sheet resistance
Gravure-printing graphene ink	—	G485653	Graphene ink	For gravure printing; contains ethyl cellulose and terpineol; gravure-printable	Used for gravure-printed conductive films; suitable for evaluating pattern transfer, edge quality, drying shrinkage, and resistance uniformity
Inkjet/photonic annealing ink	—	G485279	Graphene ink	Suitable for inkjet printing; can undergo photonic annealing	Used for inkjet printing and photonic annealing studies; suitable for evaluating how post-treatment affects resistance reduction, film integrity, and substrate tolerance

Table 2 | Graphene Slurries, Dispersions, and Composite Conductive Slurries

Category	CAS No.	Aladdin Cat. No.	Name	Specification or Purity	Product Features and Applications
Organic-solvent nanoplatelet slurry	7782-42-5	G139807	Industrial Graphite Nanoplatelet NMP Paste	Industrial-grade graphene nanoplatelet content: 1–5 wt%; dispersant content: 0.2–1.0 wt%	Dispersant content is specified; suitable for studying how dispersant ratio affects platelet contact, slurry viscosity, and film resistance
Aqueous nanoplatelet slurry	7782-42-5	G492369	Industrial Graphite Nanoplatelet Aqueous	Industrial-grade graphene nanoplatelet content: 5 wt%; dispersant content: 0.15 wt%	Aqueous graphene nanoplatelet slurry; can be used for aqueous conductive inks, coating film formation, and conductive-contact studies under low dispersant content
Graphene platelet/carbon nanotube composite slurry	7782-42-5	G139808	Graphite Nanoplatelet Carbon Nanotubes Aqueous Paste	GNP and CNT content: 1–5 wt%; GNP:CNT = 1:1; dispersant content: 0.2–1.0 wt%	Graphene nanoplatelet and carbon nanotube composite system; suitable for studying platelet bridging, tubular bridging, and low-loading conductive network construction
Organic-solvent graphene slurry	—	G494546	Graphene DMF slurry	≥98%; thickness: 0.55–3.74 nm; diameter: 0.5–3 μm; number of layers: <10	Clear information on platelet thickness, diameter, and number of layers; suitable for studying the effects of platelet size on percolation threshold, film resistance, and dispersion stability
Conventional organic graphene slurry	7782-42-5	G139801	Graphene NMP Paste	Graphene content: 1–1.5 wt%; dispersant content: 0.2–0.3 wt%	Can be used for initial screening of conductive ink formulations; suitable for comparing the relationship among graphene content, dispersant content, and film resistance
Alcohol-based graphene slurry	—	G494548	Graphene ethanol slurry	≥98%; thickness: 0.55–3.74 nm; diameter: 0.5–3 μm; number of layers: <10	Can be used to study dispersion stability in alcohol media, substrate wetting, solvent evaporation, and film-forming shrinkage
High-concentration graphene dispersion	—	G466335	Graphene dispersion	10 mg/mL, dispersed in NMP	Suitable for thin-film preparation, formulation dilution, and dispersion-stability evaluation; can be used to examine how concentration changes affect film resistance
Aqueous surfactant-containing dispersion	—	G466037	Graphene dispersion	0.5–1.0 mg/mL aqueous solution, containing a nonionic surfactant	Contains a nonionic surfactant; suitable for studying aqueous dispersion stability, wettability, and the influence of surfactant residues on conductive contact

Table 3 | Graphene Powders, Microsheets, and Nanoplatelet Conductive Fillers

Category	CAS No.	Aladdin Cat. No.	Name	Specification or Purity	Product Features and Applications
Large-diameter reduced graphene	7782-42-5	G196552	Large diameter chemical reduction graphene	Diameter: 1–100 μm	Large-diameter platelets favor long-distance bridging; suitable for studying low-loading network formation, sedimentation, coating roughness, and nozzle clogging risk
Thin-layer physical-method graphene powder	—	G196540	Physical method of graphene powder	≥99%; thickness: <1.7 nm; diameter: 8 × 8 μm	Clear thickness and lateral-size information; suitable for evaluating how the platelet diameter-to-thickness ratio affects percolation networks, viscosity changes, and processability
Large-diameter thin-layer graphene powder	—	G196543	Physical method of graphene powder	≥99.7%; thickness: <3 nm; diameter: 80 × 80 μm	Represents large-size thin-layer platelets; can be used to study long-distance conductive pathways, film roughness, sedimentation, and process compatibility
Conductive graphene powder	1034343-98-0	G476622	Graphene	Powder, conductivity >10³ S/m	Can be used as a conductive filler reference for comparing powder conductivity, dispersion state, and composite-film resistance
Graphene microsheets	1034343-98-0	G758170	Graphene microsheets	2–10 nm thick, 5 µm wide	Clear size information; suitable for studying the effects of medium platelet size and platelet thickness on film conductivity, surface morphology, and mechanical integrity
High-specific-surface-area graphene nanoplatelets	7782-42-5	G434035	Graphene nanoplatelets	Surface area 750 m²/g	High-specific-surface-area platelets can be used to study the relationship among interfacial interactions, viscosity increase, dispersion difficulty, and conductive contact
Medium-to-large particle-size graphene nanoplatelets	7782-42-5	G742459	Graphene nanoplatelets	Particle size 10–30 μm; specific surface area 30–80 m²/g	Represents medium-to-large particle-size platelets; suitable for comparing particle size, specific surface area, coating packing, and percolation network formation

Table 4 | Oxidized, Reduced, and Functionalized Graphene Materials for Interfacial Control

Category	CAS No.	Aladdin Cat. No.	Name	Specification or Purity	Product Features and Applications
High single-layer-ratio graphene oxide solution	7782-42-5	I489798	Industrial-grade graphene oxide solution	Single-layer ratio >95%, 0.8–1.2 nm	Suitable for studying aqueous dispersion, uniform film formation, and post-reduction construction of conductive networks; final resistance should be evaluated together with the reduction treatment
Aqueous reduced graphene oxide dispersion	—	R485644	Reduced graphene oxide	10 mg/mL, dispersed in H₂O	Aqueous reduced graphene oxide dispersion; can be used for aqueous conductive films, platelet connectivity, and resistance stability after film formation
Sulfonated reduced graphene oxide	—	S477872	Sulfonated reduced graphene oxide	Sodium salt	Sulfonated structure helps aqueous dispersion and interfacial control; can be used to compare the balance between dispersion stability and conductive contact
Silane-modified graphene	—	G477237	Graphene	Silane-modified	Used for interfacial bonding studies in polymer matrices, inorganic substrates, or oxide surfaces; suitable for evaluating adhesion, bending resistance, and resistance stability
Small-size carboxylated graphene	7782-42-5	G196556	Carboxylated graphene (small size)	Diameter: 50–200 nm; single-layer ratio: >98%; carboxyl ratio: 8.0 wt%	Small-size carboxylated platelets are suitable for studying dispersion stability, interfacial interactions, and the effects of functional groups on platelet contact and conductivity changes

Table 5 | Structured Conductive Networks and Polymer Composite Systems

Category	CAS No.	Aladdin Cat. No.	Name	Specification or Purity	Product Features and Applications
Three-dimensional graphene structural material	—	G494572	3D graphene	—	Can be used to study through-conductive networks, three-dimensional connectivity, compression stability, and structural resistance changes
Graphene/polymer composite pellets	—	G487609	Graphene nanoplatelets/Polypropylene pellet	—	Used for polymer conductive composite studies; suitable for evaluating the balance among filler content, percolation threshold, molding processability, and mechanical properties

Table 6 | Carbon Nanotubes, Polymer Matrix, and Reference Carbon Fillers

Category	CAS No.	Aladdin Cat. No.	Name	Specification or Purity	Product Features and Applications
Long multi-walled carbon nanotube conductive filler	308068-56-6	C313046	Carbon nanotube, multi-walled	≥95%; OD: 8–15 nm; length: ~50 μm; SSA: >140 m²/g	High aspect ratio; can be used to build bridging-type conductive networks and is suitable for studying percolation connectivity at low filler loading, viscosity increase, and entanglement risk
Large-diameter multi-walled carbon nanotube conductive filler	308068-56-6	C139870	Carbon nanotube, multi-walled	≥70%; outer diameter: 30–60 nm; length: 1–10 μm	Can be used to compare the effects of tube diameter, length, and bundle morphology on conductive networks, dispersion stability, and processing flowability
Hydroxylated multi-walled carbon nanotube interfacial-control filler	308068-56-6	C139883	Carbon nanotube, multi-walled	>90%; inner diameter: 5–10 nm; outer diameter: 10–30 nm; length: 10–30 μm	Hydroxylated surfaces help dispersion in polar systems and interfacial bonding; suitable for studying improved dispersion, filler contact, and mechanical reliability of composites
Short multi-walled carbon nanotube processing reference filler	308068-56-6	C140997	Carbon nanotube, short multi-walled	≥98%; outer diameter: 20–30 nm; length: 0.5–2 μm	Short-tube structure is suitable for studying the effect of tube length on percolation threshold, nozzle clogging, line continuity, and composite-film resistance
Short hydroxylated multi-walled carbon nanotube interfacial-control filler	308068-56-6	C139844	Carbon nanotube, multi-walled	≥95%; -OH functionalized; ID: 5–15 nm; OD: >50 nm; length: 0.5–2 μm	Combines short-tube dimensions with hydroxylated surfaces; can be used to study dispersion stability, interfacial interactions, and conductive-contact changes in aqueous or polar systems
Graphitized multi-walled carbon nanotube high-purity conductive filler	308068-56-6	C293523	Carbon nanotube, multi-walled	≥99.9% metals basis; graphitized; OD: 30–50 nm; length: ≤10 μm	Graphitization treatment and metal impurity control are specified; suitable for high-purity conductive networks, impurity-effect studies, and resistance-stability evaluation
Polylactic acid matrix material	26100-51-6	P169115	Polylactic acid	Mw ~60,000	Can serve as a thermoplastic polymer matrix for reproducing or extending studies on filler content, printability, and mechanical-property balance in PLA/multi-walled carbon nanotube conductive composites
Particulate conductive carbon black filler	1333-86-4	C742510	Acetylene carbon black	Lithium-ion battery electrode material	Particulate conductive carbon material; can serve as a reference filler for graphene and carbon nanotube systems to compare percolation differences among particulate, platelet, and tubular fillers
Graphitized carbon nanopowder	1333-86-4	C431910	Carbon, mesoporous	≥99.95% metals basis, nanopowder, graphitized, <500 nm particle size (DLS)	Graphitized nanocarbon powder can be used as a conductive-filler reference; suitable for studying particle size, graphitization degree, metal impurity control, and film resistance
Mesoporous carbon filler	1333-86-4	C431911	Carbon, mesoporous	≥99.95% metals basis, average pore diameter 100 ± 10 Å typical	Porous carbon material can be used to study pore structure, particle packing, liquid absorption, and the influence of conductive ink rheology on film-forming performance

Note: The above are representative Aladdin products. More product specifications can be searched on the Aladdin website by product name, CAS number, or catalog number.

References

[1] Bauhofer W., Kovacs J. Z. A Review and Analysis of Electrical Percolation in Carbon Nanotube Polymer Composites. Composites Science and Technology, 2009, 69(10): 1486–1498. DOI: 10.1016/j.compscitech.2008.06.018.

[2] Li J., Kim J. K. Percolation Threshold of Conducting Polymer Composites Containing 3D Randomly Distributed Graphite Nanoplatelets. Composites Science and Technology, 2007, 67(10): 2114–2120. DOI: 10.1016/j.compscitech.2006.11.010.

[3] Li C., Thostenson E. T., Chou T. W. Dominant Role of Tunneling Resistance in the Electrical Conductivity of Carbon Nanotube-Based Composites. Applied Physics Letters, 2007, 91: 223114. DOI: 10.1063/1.2819690.

[4] Li J., Ma P. C., Chow W. S., To C. K., Tang B. Z., Kim J. K. Correlations Between Percolation Threshold, Dispersion State, and Aspect Ratio of Carbon Nanotubes. Advanced Functional Materials, 2007, 17(16): 3207–3215. DOI: 10.1002/adfm.200700065.

[5] Hughes V., Tabiai I., Chizari K., Therriault D. 3D Printable Conductive Nanocomposites of PLA and Multi-walled Carbon Nanotubes. Sigma-Aldrich / Merck Technical Article.

[6] Secor E. B., Hersam M. C. Emerging Carbon and Post-Carbon Nanomaterial Inks for Printed Electronics. Journal of Physical Chemistry Letters, 2015, 6: 620–626. DOI: 10.1021/jz502431r.

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