Carbomer enhances cosmetic textures through key formulation techniques, with specific types like AC-Carbomer U21 achieving a rapid self-wetting time of just 1.5 minutes for easy dispersion, while providing high viscosity stability at 0.2% concentration and pH 7.5 and effective ion resistance under conditions like 0.1%wt NaCl for stable gels and lotions.

Formulation Technology

The charm of carbomer lies in that it is like magic powder in cosmetic formulations, but the release of its magic entirely depends on precise formulation processes.

Once you master the core technologies from dispersion, neutralization to stability control, you can skillfully handle various complex formulations and create the ideal texture and skin feel.

Its core process can be summarized as a precise "activation" process: first, fully wet the individual powder through efficient dispersion, then extend the molecular chains through accurate neutralization, and finally form a strong three-dimensional network structure.

Dispersion

Carbomer powder is prone to agglomeration when exposed to water, forming insoluble "fish eyes", which will completely destroy the uniformity and final transparency of the formulation.

The key lies in the principle of "dry powder dispersion in water": the carbomer powder must be slowly and evenly sprinkled into the vortex of the aqueous phase (or solvent) while stirring with a high-speed shear mixer (homogenizer).

Insufficient stirring speed or too fast addition speed will lead to agglomeration. For new carbomers such as U20 and U21 with extremely short self-wetting time (only 1.5-3 minutes), their initial dispersion viscosity is low, which greatly reduces the operation difficulty and agglomeration risk, and even small-batch laboratory preparation can be easily carried out.

Traditional 940 and 980 require more careful dispersion operations, but their advantage lies in bringing extremely high viscosity and transparency.

Neutralization

Carbomer has almost no viscosity under acidic conditions. Only when the pH value of the system is adjusted to neutral or weakly alkaline (usually 6.5-7.5), the carboxyl groups on its molecular chains are neutralized and fully extended due to electrostatic repulsion, so that a strong three-dimensional hydrated gel network can be formed instantly, and the viscosity increases exponentially.

Common neutralizers include triethanolamine (TEA) or sodium hydroxide (NaOH) .

Choosing different neutralizers will slightly affect the final skin feel; for example, triethanolamine may bring a more slippery touch.

The key of neutralization operation is to add slowly and drop by drop with continuous stirring to ensure that the local area is not over-alkaline, avoiding bubble generation or damage to the gel structure.

When the neutralizer is added in excess, resulting in excessively high pH, the viscosity will decrease instead, so it is crucial to use a pH meter for endpoint monitoring.

Selection and Process

When your formulation contains electrolytes (such as sunscreens, certain active ingredients or salts), you must give priority to carbomers with strong ion resistance, such as AC-Carbomer U20 or U21.

Ions will compress the electric double layer of carbomer molecular chains, weaken their hydration, and lead to serious viscosity loss.

Under 0.1% NaCl condition, U20 and 980 can maintain relatively higher viscosity.

Therefore, when preparing sunscreen lotions or products containing a large amount of inorganic salts, choosing U20 can ensure the stability of the product during shelf life and use.

For ethanol-containing systems (such as waterless hand sanitizers, hair sprays), AC-Carbomer 940 and 980 are classic choices. They can form crystal clear alcohol gels, but it should be noted that ethanol will accelerate water evaporation, so dispersion operation should be faster to avoid surface film formation.

Texture Enhancemen

The essence of texture improvement lies in understanding and controlling the rheological properties (such as long rheology and short rheology) of different carbomers and their direct correlation with skin feel, so as to tailor the most suitable texture scheme for specific formulations.

Rheological Properties

Carbomers can be roughly divided into two categories: "long rheology" and "short rheology". Long rheology polymers like AC-Carbomer U20 can form a gel structure with elasticity and cohesion.

When you apply it, you will feel a plump, luxurious and thick feeling, and the paste seems to be "pulled up", providing a strong wrapping feeling and moisturizing experience, which is very suitable for high-end night creams or nourishing masks.

On the contrary, AC-Carbomer 940, 981 and U21 belong to short rheology type, and their structure will thin rapidly when subjected to shear force (such as application), and fluidity increases instantly.

This brings an ultimate skin feel of instant water-like texture upon contact, refreshing and non-greasy, with almost no sense of existence after application, which is an ideal choice for summer moisturizing gels, refreshing lotions and serums.

AC-Carbomer 980 is between the two, providing a balanced experience with a little elasticity and smoothness.

Synergistic Effect

Compound use of carbomers with different rheological properties is an advanced skill for senior formulators to "carve" skin feel.

For example, when designing a sunscreen lotion, you can compound long rheology AC-Carbomer U20 with short rheology AC-Carbomer U21.

U20 provides a strong ability to resist electrolyte interference in sunscreens, and lays a rich base texture for the lotion, ensuring the stability of the product;

The added U21 can neutralize the too thick skin feel, inject a touch of refreshment, and further improve ion resistance, finally creating a high-quality product with stable texture, light skin feel, smooth application and no white residue.

This "1+1>2" strategy allows you to jump out of the limitations of a single raw material and create a unique texture level just like blending cocktails.

Select the appropriate carbomer according to the texture target:

Suspension Technology

The three-dimensional network structure of carbomer can not only thicken, but also effectively suspend particles:

• Suspending a touch of pearlescence in serum to add high-end      visual appeal to the product, with pearlescence evenly distributed during      use.

• Firmly "locking" scrub particles in scrub to prevent      them from depositing at the bottom of the tube, ensuring that each use can      squeeze out scrub particles with uniform concentration, thus providing a      stable and effective cleaning and exfoliating experience.

• In products containing petals or plant extracts, these      beautiful decorations are evenly distributed throughout the product to      enhance its shelf appeal. AC-Carbomer 980 and AC-Carbomer 940 are      particularly suitable for such formulations due to their excellent      suspension ability.

Application Scenarios

Precise selection of carbomer model is the key to successful formulation, and its core lies in the precise matching of rheological properties (such as long rheology and short rheology), ion resistance of different models with the physical and sensory requirements of specific products.

In transparent gel products (such as moisturizing gel, hair styling gel), the primary goal of the formulation is to achieve extremely high transparency, refreshing skin feel and fast film-forming property.

AC-Carbomer 940 and AC-Carbomer 980 are classic choices here. They can build a crystal clear gel matrix with very few bubbles, which is highly attractive visually.

AC-Carbomer 940 is especially famous for its "short rheology" characteristic. Its viscosity drops instantly during application, bringing a refreshing feeling of instant water-like texture without stickiness, which is very suitable for summer moisturizing products.

For transparent waterless hand sanitizers or hair sprays containing alcohol, AC-Carbomer 980 shows better compatibility, can stably form alcohol gel, and ensure that the product remains transparent and uniform during storage and use.

When the formulation turns to creams and lotions, the challenge lies in balancing thick moisturizing feeling with light spreadability. Creams pursuing luxurious and plump texture (such as nutritional night cream) can choose AC-Carbomer U20.

Its "long rheology" characteristic endows the cream with excellent elasticity and cohesion. When applied, a distinct thick wrapping feeling can be felt, and the moisturizing effect is long-lasting. For daily lotions that hope for lighter and smoother skin feel, AC-Carbomer 980 can be selected. While providing moderate thickening and suspension capacity, it has a balanced skin feel and will not be too thick.

In these emulsification systems, the strong three-dimensional network structure of carbomer can effectively suspend active ingredients, pigment particles or microbeads, prevent oil phase floating or solid particle sedimentation during storage, and ensure the stability and efficacy consistency of each bottle of product.

Modern sunscreen and functional products put forward higher requirements for carbomers: they must be able to withstand high concentrations of electrolytes and active ingredients.

Many chemical sunscreens in sunscreen are oily ingredients themselves, and the ion strength of the whole system is high, so ordinary thickeners are prone to viscosity collapse. This is the stage where AC-Carbomer U20 and U21 show their talents.

Their excellent ion resistance makes them an ideal choice for sunscreen formulations, which can ensure that the product maintains stable viscosity and delicate cream even when containing a large amount of sunscreen, without water separation or delamination.

Especially AC-Carbomer U21, while providing high ion resistance, it also maintains an extremely refreshing and non-greasy skin feel, which is very suitable for daily protective products that need frequent reapplication or pursue light skin feel.

In personal cleansing products (such as shampoo, body wash), the role of carbomer goes beyond thickening and is more related to conditioning function.

AC-Carbomer U20 and AC-SF-1 are widely used here. They can not only effectively thicken transparent shampoo and body wash, endow the product with plump texture, but also their formed gel network can help suspend pearlescent paste or conditioning factors, make the product appearance more beautiful, and improve the smoothness of hair after washing.

AC-Carbomer U21 is often used in cleansing gel and shower gel due to its excellent dispersibility and refreshing skin feel, which can be easily rinsed off without leaving a greasy feeling.