Why Are Daily Chemical Products Prone to Viscosity Thinning in Summer? Core Mechanisms, Troubleshooting Methods, and Solutions

1. Identifying the Nature of the Problem Based on the Symptoms of Viscosity Thinning

When daily chemical products show a decrease in viscosity during summer, the issue should not simply be attributed to “high temperature.” An increase in temperature does reduce the viscosity of most liquid systems, but the extent of viscosity thinning mainly depends on whether the thickening structure in the formulation remains stable.

In products such as shampoos, shower gels, dishwashing liquids, hand soaps, conditioners, creams, and lotions, viscosity usually comes from surfactant micellar networks, hydrated and entangled polymer structures, or lamellar gel structures formed by fatty alcohols and emulsifiers. Fragrances, solubilizers, and nonionic surfactants often affect product viscosity by altering micellar structure, dissolution behavior, cloud point, and phase equilibrium. High summer temperatures, temperature fluctuations during storage and transportation, and raw material variations may weaken or alter these structures, causing the product to become thinner, show reduced wall-clinging ability, and flow more easily. In severe cases, turbidity, syneresis, phase separation, or abnormal odor may also occur.

Therefore, the first step in solving viscosity thinning is to determine which type of thinning has occurred.

1.1 Reversible Thermal Thinning

Reversible thermal thinning refers to a situation in which a product becomes thinner at high temperature, but its viscosity can largely recover after the product is returned to around 25°C and left standing for a period of time. This type of thinning usually indicates that the formulation structure is temperature-sensitive, but the system has not undergone obvious permanent damage. Common causes include weakened micellar entanglement, changes in polymer hydration state, changes in the dissolution state of nonionic surfactants, and weakening of fatty alcohol lamellar structures at high temperature.

1.2 Irreversible Viscosity Loss

Irreversible viscosity loss refers to a situation in which a product becomes thinner after high-temperature storage and the viscosity cannot recover even after the product returns to room temperature. This type of problem is usually not caused by temperature alone. It may involve microbial contamination, polymer degradation, pH drift, phase changes, abnormal raw material batches, or production process issues. Systems containing polymeric thickeners such as hydroxyethyl cellulose (HEC), sodium carboxymethyl cellulose (CMC-Na), xanthan gum, and guar gum should pay particular attention to preservation and production hygiene. If enzymes produced by microorganisms degrade polymer molecular chains, the viscosity loss is usually difficult to reverse by cooling.

1.3 Phase-Instability-Related Thinning

If viscosity thinning is accompanied by turbidity, syneresis, phase separation, precipitation, flocculent matter, or abnormal odor, the product may already have developed phase instability. This type of problem is common in high-salt systems, high-active-content systems, concentrated systems, systems containing relatively high levels of fragrance or solubilizers, and creams or hair care systems containing fatty alcohols and emulsifiers. Phase instability cannot be solved simply by adding more thickener. Instead, formulation compatibility, high-temperature stability, and production process conditions should be re-examined.

2. The Essence of Viscosity Thinning: Reduced Stability of the Thickening Structure

Product viscosity is not determined by a single raw material alone, but by the combined structures within the formulation. The essence of summer viscosity thinning is the reduced stability of these structures under the influence of high temperature, electrolytes, fragrance, pH, microorganisms, or processing conditions.

Thickening Structure	Common Systems	Risk of Summer Viscosity Thinning
Surfactant micellar structure	AES/SLES, CAPB, NaCl systems	Changes in salt level, temperature, surfactant ratio, fragrance, and electrolytes may weaken effective micellar entanglement.
Hydrated and entangled polymer structure	HEC, HPMC, CMC-Na, xanthan gum systems	Temperature-related viscosity decrease, insufficient hydration, electrolyte effects, and microbial enzyme degradation.
Micellar/phase structures affected by fragrances, solubilizers, and nonionic surfactants	AEO, fatty alcohol polyoxyethylene ethers, fragrance solubilization systems	Increased temperature, salt content, fragrance composition, and solvent environment may change cloud point, transparency, micellar structure, and phase equilibrium, causing viscosity fluctuation or turbidity.
Fatty alcohol lamellar gel structure	Conditioners, creams, lotion systems	High temperature, cooling process, fatty alcohol ratio, and emulsifier ratio affect the strength of the lamellar structure.

3. Common Causes of Summer Viscosity Thinning

3.1 Salt Curve Issues: More Salt Does Not Always Mean Higher Viscosity

In cleansing daily chemical products, alcohol ether sulfate (AES) systems are very common. Among them, sodium laureth sulfate (SLES) is a common type of AES anionic surfactant. SLES is often used together with cocamidopropyl betaine (CAPB) and sodium chloride (NaCl) to form a salt-thickened system.

The viscosity change of this type of system follows a typical salt curve. At low salt levels, NaCl can screen the electrostatic repulsion between anionic surfactant head groups, making it easier for micelles to form longer structures and generate effective entanglement, thereby increasing system viscosity. When the salt level reaches an appropriate range, viscosity reaches a relatively high level. If the salt level continues to increase, micellar structure and intermicellar interactions may change, effective entanglement may weaken, and viscosity may decrease instead. Possible mechanisms include changes in micellar morphology, increased branching, phase changes, or an increased tendency toward salting-out.

For salt-thickened systems, summer viscosity thinning often occurs because the formulation is already close to the peak of the salt curve or is within a sensitive range at room temperature. Increased temperature, fragrance addition, changes in the salt content naturally carried by raw materials, or an increase in other electrolytes may all shift the salt curve position, change micellar morphology and phase equilibrium, and move the system away from its optimal thickening range. This may appear as viscosity loss at high temperature, turbidity, or reduced stability.

If salt is blindly added to this type of formulation, it may lead to misjudgment during small-scale trials or local mixing stages. However, after high-temperature storage, temperature cycling, or scale-up production, the system is more likely to develop viscosity thinning, turbidity, or phase instability.

3.2 Improper Surfactant Ratio and Electrolyte Load

The ratio of SLES to CAPB affects micellar morphology and salt-thickening efficiency. CAPB does more than support foaming and improve mildness; it also works together with anionic surfactants to influence micellar structure. When the ratio is appropriate, the system is more likely to form effective entanglement. When the ratio deviates from the optimal range, viscosity becomes more sensitive to salt level and temperature.

At the same time, electrolytes in the formulation do not come only from added NaCl. Sodium citrate, EDTA salts, pH adjusters, preservative salts, plant extracts, functional additives, the salt naturally carried by AES/SLES or CAPB raw materials, and water hardness can all change the ionic strength of the system.

For salt-thickened systems, changes in electrolytes may shift the salt curve. For polymer systems, electrolytes may reduce thickening efficiency. For nonionic surfactant systems, electrolytes may change the cloud point and dissolution state. The specific effect depends on the type of salt, surfactant structure, fragrance, and solvent system.

3.3 Fragrances, Solubilizers, and Nonionic Surfactants Affect Micellar Structure

Fragrances, solubilizers, oils, silicone oils, ethanol, propylene glycol, and small polyethylene glycol molecules do more than provide odor or improve solubility. They may enter the micellar interior or change the solvent environment of the aqueous phase, thereby affecting micellar length, degree of entanglement, and the position of the salt curve.

In some formulations, the base system remains stable without fragrance, but viscosity thinning occurs at high temperature after fragrance is added. This indicates that the problem is not necessarily caused by SLES or salt, but may be due to the fragrance and solubilization system altering the micellar structure.

Fatty alcohol polyoxyethylene ethers, also known as alcohol ethoxylates (AEO), and most other ethoxylated nonionic surfactants are temperature-sensitive. As temperature increases, the hydration ability of polyoxyethylene chains decreases. When the system approaches the cloud point, turbidity, phase changes, or viscosity fluctuations may occur. AEO-9 or similar nonionic surfactants are not unusable, but their dosage, degree of ethoxylation, salt content, fragrance system, and storage and transportation temperature should be evaluated comprehensively.

3.4 Insufficient Polymer Hydration or Polymer Degradation

Low-active cleansing products often use polymeric thickeners such as HEC, hydroxypropyl methylcellulose (HPMC), CMC-Na, and xanthan gum to increase viscosity. Their thickening effect depends on the hydration, extension, and entanglement of polymer molecular chains.

If the polymer is not sufficiently dispersed, the hydration time is insufficient, or the addition sequence is unreasonable, the initial viscosity of the product may be unstable, and viscosity fluctuations may easily occur later. As temperature increases, the viscosity of the aqueous phase decreases and interactions between polymer chains weaken, which can also cause a certain degree of thermal thinning.

Systems containing natural or semi-natural polymeric thickeners should pay attention to preservation. If the preservative system is insufficient, production hygiene is poor, or microorganisms are introduced through raw materials, high summer temperatures may accelerate microbial growth. Enzymes produced by microorganisms can degrade polymer molecular chains, causing irreversible viscosity loss. In this case, increasing the cellulose dosage can only temporarily improve apparent viscosity and cannot solve the root cause.

3.5 High-Salt, High-Active, and Concentrated Systems Are More Prone to Viscosity Fluctuations

In high-salt, high-active, and concentrated systems, the proportion of the aqueous phase is lower, and interactions among surfactants, salts, fragrances, and solvents become more concentrated. Small changes in salt level, fragrance, pH, or raw material batches may cause changes in viscosity, transparency, or phase state.

These systems cannot simply copy the thickening methods used in ordinary low-active formulations. Salt addition and cellulose thickening methods that are effective in low-active systems may cause turbidity, precipitation, phase separation, or high-temperature viscosity thinning in concentrated systems. For high-active and concentrated systems, formulation adjustment should focus on improving stability under high temperature, low temperature, and temperature cycling conditions.

3.6 Fatty Alcohol Lamellar Gel Structures Are Affected by High Temperature and Processing Conditions

In conditioners, creams, and lotions, fatty alcohols such as cetyl alcohol, stearyl alcohol, and cetearyl alcohol often form lamellar gel structures with emulsifiers and water. This structure can increase system viscosity, improve sensory feel, and enhance the stability of oil-water systems.

If the fatty alcohol ratio, emulsifier ratio, cooling rate, stirring intensity, or addition temperature is inappropriate, the lamellar gel structure may not form sufficiently. High temperature may weaken the lamellar gel network or promote changes in crystal form and phase state, causing the product to become softer, lose viscosity, undergo syneresis, or separate. This type of system should not rely solely on aqueous-phase thickeners to restore viscosity. Instead, the structural strength jointly formed by fatty alcohols, emulsifiers, and processing conditions should be optimized.

3.7 Production Process and Raw Material Batch Variations

When the same formulation is stable in small-scale trials but becomes thinner during mass production, the common cause is often not the formulation ratio itself, but production process conditions and raw material variations. Insufficient hydration of cellulose can lead to incomplete viscosity build-up. Adding salt all at once or too quickly may create locally high salt concentrations and disrupt the micellar structure. Excessively long high-speed shearing may affect polymers or lamellar structures. Adding fragrance at an overly high temperature may change the solubilization state. Changes in the salt naturally carried by raw materials, active matter content, pH, and water hardness can also alter the final viscosity. Product viscosity is formed during production, so process control has a direct impact on the risk of viscosity thinning.

4. Troubleshooting and Verification of Viscosity Thinning

Viscosity thinning should be investigated step by step. Formulation adjustments should be avoided before the cause is clear.

4.1 Determine Whether the Viscosity Thinning Is Reversible

Take the thinned sample, return it to around 25°C, leave it standing for 24 hours, then remeasure viscosity and observe appearance, odor, pH, and phase separation.

Observation	Preliminary Judgment
The product becomes thinner at high temperature and largely recovers after cooling.	Mostly reversible thermal thinning.
The product becomes thinner at high temperature and does not recover after cooling.	Microorganisms, polymer degradation, pH drift, or raw material abnormalities should be investigated.
The product becomes thinner and is accompanied by turbidity, syneresis, phase separation, or precipitation.	Treat as phase instability.
Abnormal odor or color change occurs.	Focus on microorganisms, preservation, and raw material stability.

Viscosity testing should be performed after the sample has been fully equilibrated at the target temperature. The instrument, spindle, speed, shear history, and reading time should be kept consistent to avoid misjudgment caused by differences in testing conditions.

4.2 Establish Salt Curves at 25°C and 40°C

For SLES + CAPB + NaCl systems, the salt curve should be re-established. It is recommended to add salt stepwise to the same base formulation using increments of 0.1% or 0.2%, and to test viscosity at both 25°C and 40°C.

If viscosity continues to increase after salt addition, the system may be in the front section of the salt curve. If viscosity decreases after salt addition, the system may already have entered the descending section of the salt curve. If a small change in salt content causes a large viscosity fluctuation, the formulation is too sensitive to production error and storage or transportation temperature. Salt-thickened systems should use a suitable salt range that remains relatively stable at high temperature.

4.3 Conduct Control Tests for Fragrance, Solubilizer, and AEO

For products that show obvious viscosity thinning after fragrance is added, control samples should be prepared:

Sample	Purpose of Evaluation
Base system without fragrance	Determine whether the main system is stable.
Base system with fragrance	Determine whether the fragrance affects viscosity.
Base system with solubilizer or AEO	Determine whether the solubilization system affects the structure.
Base system with both fragrance and solubilizer	Determine the combined effect of the two.

If the base system is stable but viscosity thinning occurs after fragrance or solubilizer is added, priority should be given to adjusting the fragrance, solubilizer, and the type and dosage of AEO.

4.4 Check pH, Electrolytes, Microorganisms, and Raw Material Batches

Thinned samples should be tested simultaneously for pH, active matter content, NaCl content, appearance, odor, and microbial indicators. Batch changes in SLES, CAPB, cellulose, fragrance, preservatives, solubilizers, and process water should also be checked. If the formulation has not changed but one batch of product shows viscosity thinning, priority should be given to checking the salt naturally carried by raw materials, active matter content, pH, water hardness, microorganisms, and addition process.

4.5 Conduct High-Temperature and Temperature Cycling Verification

Viscosity thinning should not be judged only by the viscosity immediately after production. Product stability should be confirmed through high-temperature and temperature cycling tests. Recommended test items include:

Test Item	Purpose of Evaluation
Initial viscosity	Confirm the basic state after production is completed.
Viscosity at 25°C	Serve as the room-temperature control.
Viscosity at 40°C or 45°C	Evaluate viscosity retention at high temperature.
Viscosity after high-temperature storage and recovery to 25°C	Determine whether viscosity thinning is reversible.
pH	Determine whether acid-base changes affect the system.
Appearance	Check for turbidity, syneresis, phase separation, and precipitation.
Odor	Evaluate fragrance changes or microbial risk.
Microbial indicators	Determine whether contamination or insufficient preservation is present.
Centrifugal stability	Evaluate phase stability.
High-low temperature cycling	Simulate temperature fluctuations during storage and transportation.

If viscosity decreases at high temperature but largely recovers after returning to room temperature, the issue can be improved by optimizing the salt curve, combining thickening systems, or adjusting the fragrance solubilization system. If viscosity remains significantly low after returning to room temperature, microorganisms, preservation, pH, raw material batches, and production process should be investigated. If turbidity, syneresis, phase separation, or precipitation occurs, the issue should be treated as phase instability rather than being addressed only by adding thickener.

5. Solutions for Different Systems

5.1 SLES + CAPB + NaCl Salt-Thickened Systems

The key solution is to adjust the salt level and surfactant ratio based on the salt curve, and to avoid relying solely on NaCl to increase viscosity.

Adjustment Direction	Function
Determine the appropriate salt level based on salt curves at 25°C and 40°C	Avoid placing the formulation in the descending section of the salt curve.
Optimize the ratio of SLES to CAPB	Improve micellar entanglement and salt response.
Reduce dependence on single-salt thickening	Reduce the impact of temperature, electrolytes, and batch variation on viscosity.
Combine with suitable polymers or associative thickeners	Improve viscosity retention at high temperature.
Control the dosage of fragrance, solubilizers, and other electrolytes	Reduce interference with micellar structure.
Optimize the salt addition sequence and addition rate	Reduce structural fluctuations caused by locally high salt concentrations.

This type of system should not be evaluated only by initial viscosity. Greater attention should be paid to viscosity changes after high-temperature storage and to reproducibility during scale-up production.

5.2 Low-Active Polymer-Thickened Systems

The key solution is to improve the stability of the polymer thickening structure while controlling preservation, hydration, pH, and electrolyte effects.

Adjustment Direction	Function
Select cellulose or gum thickeners suitable for the system	Improve aqueous-phase viscosity and storage stability.
Appropriately adjust polymer dosage or viscosity grade	Improve the consistency of low-active systems.
Ensure sufficient dispersion and hydration	Reduce viscosity fluctuations after production.
Control pH and electrolyte content	Reduce the loss of polymer thickening efficiency.
Optimize the preservative system and production hygiene	Reduce the risk of irreversible viscosity loss caused by microbial enzyme degradation.
Control process water quality	Reduce the impact of hardness, microorganisms, and impurities on system stability.

5.3 High-Salt, High-Active, and Concentrated Systems

The key solution is to reduce the system’s sensitivity to fluctuations in salt, electrolytes, and fragrance, and to avoid focusing only on room-temperature viscosity.

Adjustment Direction	Function
Reduce excessively high salt levels	Reduce the risk of entering the descending section of the salt curve.
Optimize the surfactant combination	Improve system compatibility and viscosity stability.
Use thickening systems with better electrolyte tolerance	Improve viscosity retention under high-salt conditions.
Control the dosage of fragrance, solvents, and nonionic surfactants	Reduce phase changes and viscosity fluctuations.
Adjust active matter concentration and aqueous-phase ratio	Improve system flowability and storage stability.
Pay attention to appearance changes such as turbidity, precipitation, and phase separation	Avoid judging stability by viscosity alone.

5.4 Systems Containing Relatively High Levels of AEO, Fragrance, and Solubilizers

The key solution is to improve the compatibility and stability of fragrances and nonionic surfactants, and to reduce their impact on micellar structure and transparency.

Adjustment Direction	Function
Adjust the AEO type or degree of ethoxylation	Improve temperature sensitivity and dissolution behavior.
Optimize fragrance type and dosage	Reduce interference of fragrance with micellar structure.
Adjust the type and dosage of solubilizer	Improve fragrance solubilization and transparency stability.
Control salt and other electrolyte contents	Reduce their impact on the dissolution state of nonionic surfactants.
Adjust the formulation based on fragrance control test results	Reduce viscosity thinning caused by fragrance or solubilizers.

5.5 Fatty Alcohol Lamellar Gel Systems

The key solution is to improve the stability of the lamellar structure jointly formed by fatty alcohols, emulsifiers, and processing conditions.

Adjustment Direction	Function
Optimize the ratio of cetyl alcohol, stearyl alcohol, and cetearyl alcohol	Improve the strength of the lamellar gel structure.
Adjust the type and ratio of emulsifiers	Improve the integrity of the emulsified structure.
Control cooling rate and stirring intensity	Promote stable formation of the lamellar structure.
Adjust the ratio of oil phase to structuring fatty alcohols	Improve high-temperature consistency and reduce the risk of syneresis.
Combine with aqueous-phase thickeners when necessary	Help improve system consistency and suspension stability.

6. Representative Chemical Classification List for Mechanism Studies and Small-Scale Verification of Summer Viscosity Thinning in Daily Chemical Products

Table 1. Products Related to Surfactants, Solubilizers, and Salt Thickening

Category	CAS No.	Aladdin Cat. No.	Name	Specification or Purity	Product Features and Applications
Anionic surfactant - sulfate type	151-21-3	S432157	Sodium dodecyl sulfate (SDS)	Anhydrous, ACS, ≥99%	Used for control experiments on micelle formation, surfactant concentration, salt response, and rheology of cleansing systems.
Anionic surfactant - ether sulfate type	9004-82-4	S196294	Sodium polyoxyethylene lauryl ether sulfate	≥25%	Used for studies on salt curves, micellar entanglement, synergistic thickening with amphoteric surfactants, and high-temperature viscosity thinning.
Anionic surfactant - sulfonate type	25155-30-0	S592217	Sodium dodecylbenzenesulfonate (SDBS)	Anion Active Matter, 85%	Used for studies on micellar behavior, foam performance, salt response, and high-active systems in household cleaning and detergent formulations.
Anionic surfactant - olefin sulfonate type	68439-57-6	S304377	Sodium α-olefin sulfonate	≥92%	Used for studies on foam, detergency, salt-thickening response, and high-temperature viscosity changes in cleansing systems.
Anionic surfactant - amino acid type	137-16-6	N476195	Sodium N-lauroylsarcosinate	UltraBio™, molecular biology grade, ultrapure grade, ≥99% (HPLC)	Used for control studies on mild cleansing systems, foam performance, pH effects, and salt sensitivity.
Amphoteric surfactant - betaine type	61789-40-0	C665446	Cocamidopropyl betaine	Actives content 28%-32% in water	Used for studies on synergistic thickening with anionic surfactants, salt curve adjustment, foam stabilization, and mildness.
Nonionic foam stabilizer/thickener - fatty acid amide type	68603-42-9	C304384	N,N-Bis(2-hydroxyethyl)cocamide	Model: 6501 (1:1)	Used for foam stabilization, auxiliary thickening, micellar structure adjustment, and salt-thickened formulation studies in cleansing systems.
Nonionic surfactant - alkyl glucoside type	58846-77-8	D112862	Decyl glucopyranoside	Biochemical reagent	Used for studies on mild cleansing systems, nonionic compatibility, transparency, cloud point, and high-temperature viscosity changes.
Nonionic surfactant - alkyl glucoside type	68515-73-1	T476404	Decyl glucoside (APG)	Moligand™, 60% in H₂O	Used for studies on mild cleansing systems, compounding with anionic surfactants, salt response, and transparency stability.
Nonionic surfactant - alkyl glucoside type	110615-47-9	L196324	Dodecyl glucoside	≥40%	Used for studies on mild cleansing systems, fragrance solubilization compatibility, foam performance, and high-temperature transparency.
Nonionic solubilizer - polyoxyethylene sorbitan ester type	9005-64-5	T274277	Polyoxyethylene sorbitan fatty acid ester	Reagent grade	Used for solubilizing fragrances and oily components; suitable for studying the effects of solubilization systems on cloud point, transparency, and viscosity.
Nonionic solubilizer - hydrogenated castor oil polyether type	61788-85-0	P1520025	PEG-60 hydrogenated castor oil	Cosmetic grade, HLB 14.0	Used for fragrance solubilization, transparent cleansing systems, high-temperature cloud point changes, and comparative studies on viscosity thinning.
Nonionic associative thickener - polyether fatty acid ester type	9005-08-7	P196301	PEG-150 distearate	Melting point: 55-58°C	Used for auxiliary thickening, rheology adjustment, reducing dependence on single-salt thickening, and improving high-temperature viscosity retention in cleansing systems.

Table 2. Products Related to Aqueous-Phase Thickeners, Rheology Modifiers, and Humectant Solvents

Category	CAS No.	Aladdin Cat. No.	Name	Specification or Purity	Product Features and Applications
Cellulose thickener - anionic type	9004-32-4	C104986	Sodium carboxymethyl cellulose (CMC)	Viscosity: 1000-1400 mPa·s, USP grade	Used for studies on aqueous-phase thickening, suspension stability, electrolyte effects, and viscosity retention after high-temperature storage in low-active cleansing systems.
Cellulose thickener - nonionic type	9004-65-3	H1506257	Hydroxypropyl methylcellulose (HPMC)	Substitution type 2910, viscosity: 400 mPa·s, methoxy: 28-30%; hydroxypropyl: 7.0-12%	Used for studies on aqueous-phase thickening, film formation, polymer hydration, and viscosity-thinning troubleshooting in low-active systems.
Cellulose thickener - nonionic type	9004-62-0	H434475	2-Hydroxyethyl cellulose (HEC)	Average Mw ~380,000	Used for studies on aqueous-phase thickening, hydration processes, high-temperature viscosity thinning, microbial enzyme-induced viscosity loss, and its relationship with preservative efficacy.
Natural gum thickener - polysaccharide type	11138-66-2	G104873	Xanthan gum	PharmPure™, USP	Used for studies on suspension stability, electrolyte-tolerant rheology, thickening of low-active systems, and viscosity changes during high-temperature storage.
Synthetic polymer thickener - polyacrylic acid type	9003-01-4	P661414	Poly(acrylic acid) (PAA)	Viscosity ≤2000 cP (25°C)	Used for studies on pH-responsive rheology, polymer neutralization, electrolyte effects, and aqueous-phase viscosity changes.
Humectant solvent - polyol type	56-81-5	G755728	Glycerol	Anhydrous, UltraBio™, molecular biology grade, ≥99.5% (GC)	Used for studies on aqueous-phase moisturization, solvent environment adjustment, viscosity changes, preservative system performance, and high-temperature stability.
Humectant solvent - diol type	57-55-6	P103433	1,2-Propanediol	ACS, ≥99.5%	Used for studies on solvent environment adjustment, dissolution of fragrances and active ingredients, effects on micellar structure, and high-temperature viscosity changes.

Table 3. Products Related to Electrolytes, pH Adjustment, Chelation, and Preservation

Category	CAS No.	Aladdin Cat. No.	Name	Specification or Purity	Product Features and Applications
Electrolyte - salt curve modifier	7647-14-5	S433744	Sodium chloride	Anhydrous, high purity, reagent grade, ≥99%	Used for salt curve construction, micellar entanglement adjustment, salt gradient experiments, and evaluation of high-temperature viscosity-thinning risk.
pH adjuster - inorganic base	1310-73-2	S111498	Sodium hydroxide	Guaranteed reagent, ≥96%	Used for pH adjustment, polyacrylic acid neutralization, pH drift studies, and viscosity change experiments.
pH adjuster - inorganic base	1310-58-3	P431767	Potassium hydroxide	Anhydrous, ≥99.95% metals basis	Used for pH adjustment, alkaline cleansing systems, soap-based systems, and studies on compatibility effects.
pH adjuster - organic acid	77-92-9	C434175	Citric acid	Anhydrous, PharmPure™, USP, JP, BP, European Pharmacopoeia (Ph. Eur.), powder	Used for studies on pH adjustment, buffer system design, polymer viscosity, and effects on preservative performance.
pH adjuster - organic acid	50-21-5	L108839	DL-Lactic acid	AR, 85-90%	Used for pH adjustment in weakly acidic cleansing systems, and for studies on polymer viscosity, preservative performance, and mild systems.
Buffer salt - organic acid salt	6132-04-3	S116311	Sodium citrate dihydrate	AR, ≥99%	Used for studies on buffer systems, electrolyte load, salt curve position, and effects on preservative systems.
Chelating agent - aminocarboxylate type	139-33-3	D684233	Disodium ethylenediaminetetraacetate	≥99%	Used for metal ion chelation, water hardness control, preservative support, and raw material batch troubleshooting experiments.
Preservative - organic acid salt type	532-32-1	S104125	Sodium benzoate	Chemically pure (CP), ≥99%	Used for studies on preservative efficacy in acidic aqueous systems, pH dependence, and microbial-induced viscosity-loss risk.
Preservative - organic acid salt type	24634-61-5	P103846	Potassium sorbate	Chemically pure (CP), ≥98%	Used for preservative efficacy evaluation in acidic aqueous systems, microbial control, and troubleshooting of irreversible viscosity thinning.
Preservative - glycol ether type	122-99-6	E109370	Phenoxyethanol	≥99%	Used for preservative efficacy, microbial control, and troubleshooting irreversible viscosity loss in polymer systems.
Preservative - hydantoin type	6440-58-0	B194375	1,3-Dimethylol-5,5-dimethylhydantoin	≥95%	Used for studies on preservative efficacy in aqueous systems, high-temperature storage stability, and microbial-related viscosity-thinning risks.
Preservative - isothiazolinone type	2682-20-4	M110103	2-Methyl-4-isothiazolin-3-one (MIT)	≥95%	Used for microbial control, preservative efficacy evaluation, and troubleshooting irreversible viscosity loss. The use concentration must comply with applicable regulations.

Table 4. Products Related to Fatty Alcohols, Emulsifying Structures, and Cationic Conditioning

Category	CAS No.	Aladdin Cat. No.	Name	Specification or Purity	Product Features and Applications
Structuring fatty alcohol - medium-to-long-chain fatty alcohol	36653-82-4	H113020	Cetyl alcohol	≥99%	Used for lamellar gel structure formation, consistency adjustment in emulsified systems, and studies on summer high-temperature stability.
Structuring fatty alcohol - long-chain fatty alcohol	112-92-5	O105097	Stearyl alcohol	≥99%	Used for structure building in conditioners, creams, and lotions; suitable for studying the effects of fatty alcohol ratio on high-temperature consistency and syneresis risk.
Mixed structuring fatty alcohol - cetyl/stearyl alcohol	8005-44-5	C1035467	Cetearyl alcohol	—	Used for building lamellar gel structures in conditioners, creams, and lotions, and for studies on high-temperature softening and viscosity retention.
Structuring fatty alcohol - long-chain fatty alcohol	661-19-8	B1519910	Behenyl alcohol	Cosmetic grade, ≥65%	Used for studies on lamellar gel structures, high-temperature softening, and structural strength in hair care, cream, and lotion systems.
Emulsifying structure aid - glyceride type	31566-31-1	G196240	Glyceryl monostearate, emulsifying grade	≥99%	Used for structure building in cream and lotion systems; suitable for studies on syneresis, high-temperature stability, and emulsified state.
Cationic surfactant - alkyl quaternary ammonium salt type	112-02-7	C466513	Hexadecyltrimethylammonium chloride solution (HTAC)	25 wt.% in H₂O	Used for conditioning in hair care systems, formation of lamellar structures with fatty alcohols, and studies on high-temperature stability.
Cationic surfactant - long-chain quaternary ammonium salt type	17301-53-0	N587655	Behentrimonium chloride	≥80%	Used for conditioning in hair care systems, fatty alcohol lamellar gel structures, and studies on high-temperature structural stability.

Note: The above list includes representative Aladdin products related to scientific research and formulation studies. They are mainly intended for studying the mechanism of summer viscosity thinning, small-scale verification, control experiments, and stability troubleshooting. This list does not represent finished product formulation recommendations, nor does it mean that the listed raw materials can be used directly in mass-produced cosmetics or daily chemical products. In actual production, raw materials of appropriate grades should be selected according to the regulations of the target market, quality standards, microbial limits, impurity control requirements, and supply requirements.

For preservatives, pH adjusters, surfactants, and other raw materials, actual application should be comprehensively confirmed based on product type, leave-on or rinse-off attributes, applicable pH range, incompatibilities in combination, maximum permitted concentration, safety assessment, and product documentation. For more product specifications, grades, and COA information, search by product name, CAS number, or catalog number on the Aladdin website.

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Non-ionic Detergents Explained: From Chemical Structure to Laboratory Use

Practical Guide to Sodium Carboxymethyl Cellulose (CMC-Na): Thickening/Stabilizing Mechanisms, Key Controls for Solution Preparation, and Selection Navigation (including Table 1 and Tables A–C)

Alcohol Ethoxylates (AEO) Explained: Structure, Key Parameters, Application Scenarios, and Aladdin’s Selection Tables (Main + Appendix)