Kaolinite - Nature , CAS No.1318-74-7

CAS: 1318-74-7 Cat. No.: K485362 Fórmula: Al₂O₃·2SiO₂·2H₂O Peso molecular: 258.16 Número EC: 215-286-4

GRADE & PURITY Native

Synonyms

Aluminum silicate

Descripción general

Description

Kaolinite can be used:In the preparation of of polysialate polymers.To prepare mullite composites by sintering kaolinite and alumina.To synthesize microporous materials such as zeolite Linde Type A (LTA) and kaoline based silicoaluminophosphate (SAPO) molecular sieves.In the synthesis of terbium pyridine-picolinate grafted kaoline, as a luminescent hybrid material.As a filler and a coating pigment in the paper industry.

Specifications

Sinónimos

Aluminum silicate

Especificaciones y pureza

Nature

Grado

Native

Nombres e identificadores

• WGK Alemania: 3
• Peso molecular: 258.16

Referencias

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3. Guangjian Tian, Yan Zhang, Yibei Jiang, Peiwei Hu, Haidong Wang, Yi Zhang.  (2023)  Nanoscale zerovalent Iron-incorporated kaolinite for hemostatic and antibacterial applications.  APPLIED SURFACE SCIENCE,      [PMID:] [10.1016/j.apsusc.2023.157879]

4. Yixuan Mao, Alain Luigi Lanzon, Botuo Zheng, Zhengxiao Xu, Jiatong Jiang, David Harbottle, Kai Yu, Mingfeng Chen, Yu Sheng, Huagui Zhang.  (2023)  Nanofluids of Amphiphilic Kaolinite-Based Janus Nanosheets for Enhanced Oil Recovery: The Importance of Stable Emulsion.  Polymers,  15  (11): (2515).  [PMID:37299314] [10.3390/polym15112515]

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6. Yanping Ji, Jiang Xu, Lizhong Zhu.  (2023)  Predicting laterite redox potential with iron activity and electron transfer term.  CHEMOSPHERE,      [PMID:36972875] [10.1016/j.chemosphere.2023.138519]

7. Zhixin Chen, Yijie Wang, Liming Hu.  (2023)  Thermal desorption mechanism of n-dodecane on unsaturated clay: Experimental study and molecular dynamics simulation.  ENVIRONMENTAL POLLUTION,      [PMID:36773689] [10.1016/j.envpol.2023.121228]

8. Chenguang Yang, Jianqiang Yin, Liqin Wu, Qiuyu Zeng, Liwei Zhang.  (2022)  Research on the Identification Mechanism of Coal Gangue Based on the Differences of Mineral Components.  ACS Omega,      [PMID:36643562] [10.1021/acsomega.2c05743]

9. Ke-wei Li, Hai-long Lu, Jackson Nkoh Nkoh, Ren-kou Xu.  (2022)  The important role of surface hydroxyl groups in aluminum activation during phyllosilicate mineral acidification.  CHEMOSPHERE,      [PMID:36563731] [10.1016/j.chemosphere.2022.137570]

10. Yongda Huang, Hongyun Hu, Chan Zou, Huimin Liu, Shuai Li, Xiaojiang Wu, Lejin Xu, Hong Yao.  (2022)  Partitioning and transformation behavior of selenium during coal combustion.  PROCEEDINGS OF THE COMBUSTION INSTITUTE,      [PMID:] [10.1016/j.proci.2022.08.083]

11. Guo Lin-yu, He Xian, Hong Zhi-neng, Xu Ren-Kou.  (2022)  Effect of the interaction of fulvic acid with Pb(II) on the distribution of Pb(II) between solid and liquid phases of four minerals.  ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH,  29  (45): (68680-68691).  [PMID:35543790] [10.1007/s11356-022-20315-w]

12. Yuchan Li, Bin Yu, Zhenqi Hu, Hong Wang.  (2021)  Construction of direct Z-scheme SnS2@ZnIn2S4@kaolinite heterostructure photocatalyst for efficient photocatalytic degradation of tetracycline hydrochloride.  CHEMICAL ENGINEERING JOURNAL,      [PMID:] [10.1016/j.cej.2021.132105]

13. Shuxin Huang, Jian Feng, Junxia Yu, Yi Wang, Jiequan Liu, Ruan Chi, Haobo Hou.  (2021)  Adsorption and desorption performances of ammonium on the weathered crust elution-deposited rare earth ore.  COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS,      [PMID:] [10.1016/j.colsurfa.2021.126139]

14. Lin Shi, Di Zhang, Jinfeng Zhao, Jianliang Xue, Mengnan Yin, Aiping Liang, Bo Pan.  (2021)  New insights into the different adsorption kinetics of gallic acid and tannic acid on minerals via 1H NMR relaxation of bound water.  SCIENCE OF THE TOTAL ENVIRONMENT,      [PMID:33434839] [10.1016/j.scitotenv.2020.144447]

15. Mei Zhong, Da Zou, Yuebing Xu, Lijun Jin, Yue Pan.  (2020)  Effect of kaolinites modified with Zr and transition metals on the pyrolysis behaviors of low-rank coal and its model compound.  JOURNAL OF THE ENERGY INSTITUTE,      [PMID:] [10.1016/j.joei.2020.11.009]

16. Yanfei Zhou, Xiaoning Liu, Jun Wang.  (2020)  Ecotoxicological effects of microplastics and cadmium on the earthworm Eisenia foetida.  JOURNAL OF HAZARDOUS MATERIALS,      [PMID:32070928] [10.1016/j.jhazmat.2020.122273]

17. Qianyue Guo, Zhenquan Wang, Qijing Xu, Han Mao, Di Zhang, Saikat Ghosh, Nihar R. Pradhan, Bo Pan, Baoshan Xing.  (2020)  Suspended state heteroaggregation kinetics of kaolinite and fullerene (nC60) in the presence of tannic acid: Effect of π-π interactions.  SCIENCE OF THE TOTAL ENVIRONMENT,      [PMID:31951837] [10.1016/j.scitotenv.2020.136559]

18. Xueyan Ye, Ruijuan Cui, Xinqiang Du, Sijia Ma, Jingtong Zhao, Ying Lu, Yuyu Wan.  (2019)  Mechanism of Suspended Kaolinite Particle Clogging in Porous Media During Managed Aquifer Recharge.  Groundwater,  57  (5): (764-771).  [PMID:30802943] [10.1111/gwat.12872]

19. Shuanglei Peng, Guancheng Jiang, Xinliang Li, Lili Yang, Fan Liu, Yinbo He.  (2017)  Synthesis, characterization and evaluation of amphoteric chitosan-based grafting flocculants for removing contaminants with opposite surface charges from oilfield wastewater.  JOURNAL OF CHEMICAL TECHNOLOGY AND BIOTECHNOLOGY,  93  (4): (968-974).  [PMID:] [10.1002/jctb.5448]

20. Li Hongliang, Song Shaoxian, Zhao Yunliang, Nahmad Yuri, Chen Tianxing.  (2016)  Comparison Study on the Effect of Interlayer Hydration and Solvation on Montmorillonite Delamination.  JOM,  69  (2): (254-260).  [PMID:] [10.1007/s11837-016-2162-0]

21. Hao Zheng, Xue Feng, Lu Zhou, Ying Ye, Jianfang Chen.  (2016)  Intercalated polyaniline–kaolinite nanocomposite prepared via in situ mechanochemical synthesis.  JOURNAL OF APPLIED POLYMER SCIENCE,  133  (32):   [PMID:] [10.1002/app.43551]

22. Zheng Tang, Ran Yin, Kaishun Bi, Heyun Zhu, Fei Han, Kelin Chen, Fenrong Wang.  (2015)  Simultaneous quantitative determination of 20 active components in the traditional Chinese medicine formula Zhi-Zi-Da-Huang decoction by liquid chromatography coupled with mass spectrometry: application to study the chemical composition variations in different combinations.  BIOMEDICAL CHROMATOGRAPHY,  29  (9): (1406-1414).  [PMID:25678253] [10.1002/bmc.3438]

23. Sheng-Nan Zhang, Yi-Tong Zhou, Jun Xia, Yu-Meng Wang, Jun-Wei Ma, Li-Kun Wang, Kashif Hayat, Shan-shan Bai, Cheng-han Li, Ming-Rong Qian, Hui Lin.  (2024)  Combined effects of cadmium and sulfamethoxazole on Eisenia fetida: Insights into accumulation, subcellular partitioning, biomarkers and toxicological responses.  SCIENCE OF THE TOTAL ENVIRONMENT,      [PMID:38761948] [10.1016/j.scitotenv.2024.173303]

24. Yang Peng, Yuping Chen, Hao Wu, Ziqin Wang, Liu Yang, Jiale Chen, Xinjuan Chen, Fu Liu, Nan Wang, Yuru Dong, Jie Liu, Jie Xiao, Ming Chen.  (2025)  Comparison of adsorption mechanisms of tungstate ions on different clay minerals.  RSC Advances,  15  (41): (34310-34321).  [PMID:40979951] [10.1039/D5RA04306A]

25. Dongyue Wang, Yuhang Meng, Aidong Tang, Huaming Yang.  (2022)  Dehydroxylation of Kaolinite Tunes Metal Oxide–Nanoclay Interactions for Enhancing Antibacterial Activity.  Minerals,  12  (9): (1097).  [PMID:] [10.3390/min12091097]

26. Danna Shan, Yan Shi, Bin Zhou, Zilin Liu, Liu Yang, Xuetao Zhu, Qishi Luo, Guanghe Li.  (2021)  Simultaneous and continuous stabilization of As and Cd in contaminated soil by a half wrapping-structured amendment.  Journal of Environmental Chemical Engineering,      [PMID:] [10.1016/j.jece.2021.105416]

27. Pengfei Cheng, Haoli Qin, Junxia Cheng, Junliang Chen, ManMan Yu, Zhiliang Li, Yao Lu, Guanlin Li, Daolin Du.  (2025)  Mechanisms of degradation of polycyclic aromatic hydrocarbons by biochar and biochar-mineral composites in the dry system.  Applied Catalysis O: Open,      [PMID:] [10.1016/j.apcato.2025.207047]

28. Yinyin Qian, Beibei Shi, Guangyao Li, Huaming Yang.  (2025)  Atomic-level insights into nanoclay for prebiotic nucleoside phosphorylation.  GEOCHIMICA ET COSMOCHIMICA ACTA,      [PMID:] [10.1016/j.gca.2025.06.025]

29. Beibei Wang, Jianchao Zhang, Xiangyu Zhu, Yuebo Wang, H. Henry Teng.  (2025)  Mineral substrates as evolutionary drivers of soil microbial diversity through the rare biosphere.  APPLIED AND ENVIRONMENTAL MICROBIOLOGY,      [PMID:41363836] [10.1128/aem.02011-25]

30. Yanbei Hou, Yixin Hu, Shuming Liu, Xu Chang, Weizhao Hu, Bin Fei.  (2026)  Effect of Platinum-Modified Kaolin on the Flame Retardancy and Ceramization of Silicone Rubber Composites.  ACS Applied Nano Materials,      [PMID:] [10.1021/acsanm.5c05115]

31. Guangyu Yang, Shihang Li, Yu Feng, Xiaofeng Shi, Lei Li, Qinpei Chen, Guohui Li, Hongyuan Ding, Jianghui Xie, Tiannian Zhou, Feng Yang, Que Huang, Changcheng Liu.  (2026)  A sodium alginate based composite aerogel for effective thermal runaway blockage and flame retardancy in lithium-ion batteries.  Journal of Energy Storage,      [PMID:] [10.1016/j.est.2026.123532]

Application Protocols

Not applicable for immunoassays.

• No WB/IHC/IF/FC protocols or dilutions are associated with this mineral product.

General handling protocols (literature; not item-specific)

• Dispersion: add powder slowly to the chosen medium under high-shear mixing; consider 0.05–0.5 wt% dispersant (e.g., sodium polyacrylate) for aqueous systems; adjust pH to >6 to minimize edge-charge-induced flocculation.
• Drying: for constant-mass preparation, heat at 105–120 °C for 2–4 h; cool in a desiccator before weighing.
• Filtration: use medium-porosity frits; allow for cake formation and potential blinding; precoat if necessary.
• Regeneration (adsorbent use): rinse with appropriate solvent, then dry or calcine depending on adsorbate thermal stability.

Biological Roles

Applicability note

• Kaolinite is an inorganic mineral and does not have intrinsic biological roles like biomolecules. However, its interactions with biological systems are of research interest.

Literature/general context (not item-specific)

• Soil science: kaolinite is a dominant clay mineral in highly weathered soils (Oxisols/Ultisols), influencing cation exchange capacity, water retention, and nutrient dynamics.
• Sorption of biomolecules: clay surfaces can adsorb proteins, enzymes, nucleic acids, and metabolites through electrostatic and hydrogen-bonding interactions; adsorption is pH- and ionic-strength dependent and can modulate activity/stability.
• Origin-of-life studies: layered silicates (including kaolinite) have been examined as scaffolds for abiotic polymerization/templating due to their surfaces and interfacial chemistry.
• Microbial interactions: microbial exudates can modify kaolinite dispersion and aggregation; conversely, kaolinite can sequester toxins or metals affecting bioavailability in environmental systems.
• Toxicology/ecotoxicology: native kaolinite is generally considered of low toxicity; primary concern is inhalation of fine particulates. In aquatic systems, suspended clay can impact turbidity and organism behavior at high concentrations.

Note

• The above points are general literature observations and not specific performance claims for this item. No clinical or therapeutic claims are made; this product is for research use only.

Buffer Applications

Not typically applicable.

• Kaolinite is an insoluble mineral and does not function as a pH buffer in solution. In aqueous systems it can influence apparent pH via surface acid–base equilibria and ion exchange, but it is not used to prepare defined buffer solutions.
• For experiments involving kaolinite suspensions, prepare your buffer independently (e.g., phosphate, acetate, Tris) and then introduce the mineral while monitoring pH drift due to surface interactions.

Green Alternatives

Context

• Kaolinite is an abundant, non-volatile, mineral solid with low inherent toxicity and no VOC emissions. It can serve as a greener alternative to some polymeric or high-energy adsorbents/supports when appropriate.

Literature-based comparison (not item-specific)

• As catalyst/support vs. traditional acids/bases:
  • Using acid-activated kaolinite or metakaolin as a solid acid for esterifications can reduce or eliminate corrosive mineral acids in liquid phase.
  • Heterogeneous solids facilitate recovery/reuse, reducing aqueous neutralization/effluent.
• As adsorbent vs. activated carbon/silica gel:
  • Kaolinite offers lower surface area than activated carbon or silica; however, it is low-cost, widely available, and thermally regenerable with minimal environmental burden.
• As inorganic filler in polymers/coatings:
  • Replaces talc or CaCO3 in certain formulations; choice depends on mechanical and optical targets. Calcined kaolin can improve opacity with lower TiO2 demand (literature), reducing resource intensity.

Trade-offs

• Lower surface area/acidity in native kaolinite may require activation (acid/calcination), which introduces processing impacts.
• Non-swelling nature eases handling but can limit access to interlayer sites compared with smectites.

Quick comparison (literature)

• Kaolinite: non-swelling, low CEC, low-to-moderate SA, thermally stable.
• Montmorillonite K10: higher acidity/SA, better catalyst but more processing.
• Silica gel: higher SA, broader pore control, but energy-intensive production.

Note: Selection should weigh lifecycle, performance, and regeneration feasibility for the specific process.

Pharmaceutical Uses

Item-specific

• This listing is Native grade with no pharmacopeial designation provided. It is intended for research use only.

Literature/general formulation context (not item-specific)

• Kaolin (a kaolinite-rich material) appears in pharmacopeias as an excipient/adsorbent and as a diluent in topical powders and pastes; stringent specifications exist for microbiology, particle size, and elemental impurities in pharmacopeial grades.
• In drug product development, engineered kaolin can act as:
  • Adsorbent to modulate moisture/oil content in semisolids
  • Filler/pigment affecting opacity and rheology
  • Carrier for controlled release after suitable modification/intercalation

Important notes

• Do not use this research-grade, Native kaolinite in human or veterinary products.
• For any excipient application, source pharmacopeial-compliant material (e.g., USP/Ph. Eur.) and verify elemental impurity profile (ICH Q3D), bioburden, and PSD.
• No medical or therapeutic claims are made; the above are general literature roles of kaolin-type materials in formulations.

Physical Properties

Item-specific specs

• Appearance: Not specified for this item; refer to CoA/Spec Sheet.
• Molecular weight (item): Not specified for this item; refer to CoA/Spec Sheet.

Literature/general values (for kaolinite mineral; not item-specific)

• Ideal formula: Al2Si2O5(OH)4
• Formula (oxide basis): Al2O3·2SiO2·2H2O (structural water)
• Molar mass (idealized): ~258.16 g/mol
• Density: ~2.58–2.63 g/cm³ (true density); bulk density depends strongly on packing/particle size
• Color: white to off-white; may be tinted by trace iron/titanium oxides
• Melting/decomposition: dehydroxylation to metakaolin ~450–650 °C; exothermic crystallization to spinel-type intermediates and mullite at higher T (>950–1000 °C) (literature)
• Thermal events (literature): endotherm near 100–150 °C (physisorbed water loss); endotherm ~450–650 °C (dehydroxylation)
• Solubility: insoluble in water and common organic solvents; dispersible as a suspension
• Surface area: widely variable with source/treatment (typically a few to tens of m²/g for native kaolinite); can be increased by acid activation/calcination
• Particle size: highly source-dependent; often submicron to tens of microns (not a specification for this item)
• Point of zero charge (literature): typically pH ~3–4 for basal planes; edge sites amphoteric
• Refractive index (literature): n ≈ 1.56–1.57
• XRD: basal spacing d001 ≈ 7.1 Å (non-swelling), diagnostic 001, 002 reflections

Notes

• All numerical values above are typical literature ranges and not specifications for this catalog item.

Quality and Grades

Item-specific (from Product Data)

• Grade: Native
• Purity/assay: Not specified for this item; refer to CoA/Spec Sheet.
• Stabilizers/additives: None indicated.

Interpretation and implications (general guidance)

• Native grade: denotes an as-mined or minimally processed kaolinite without deliberate chemical activation, acid treatment, or surface modification. Such materials retain the intrinsic 1:1 phyllosilicate structure, modest surface area, and relatively low cation exchange capacity (vs. smectites).
• Variability: Native kaolinite properties (particle size distribution, trace mineral content such as quartz, mica, anatase/rutile, iron oxides) can vary by deposit and beneficiation process. For application-critical work, verify via CoA and, if needed, in-house XRD/ICP/PSD analysis.
• Comparison to activated/engineered grades (literature):
  • Acid-activated/calcined kaolin: higher surface area and acidity; useful for catalysis/adsorption.
  • Surface-modified kaolin: tailored hydrophobicity or coupling for polymer composites.
• Chromatography grade, HPLC grade, metal content, UV cutoff: Not specified for this item; refer to CoA/Spec Sheet.

Recommendations

• For reproducible catalysis or adsorption studies, characterize batch by BET, XRD, FTIR (OH bands), and zeta potential under your conditions.
• If very low trace metals or specific PSD is required, contact Technical Support for available specifications or custom materials.

Reaction and Applications

Applicability note

• As an inert, insoluble aluminosilicate, kaolinite is not a reagent but is widely used as a support, filler, and heterogeneous phase. Catalytic activity depends on pretreatment (e.g., calcination or acid activation); native material is weakly acidic.

Laboratory/research applications (literature; not item-specific)

• Solid support and adsorbent: used to immobilize catalysts (e.g., metal salts, nanoparticles) and to adsorb dyes, phenols, and ions from aqueous media; surface hydroxyls enable ligand anchoring after appropriate functionalization.
• Heterogeneous catalysis: acid-activated or calcined kaolinite (metakaolin) can catalyze esterification, transesterification, and select dehydration/condensation reactions. Activity increases with surface area and acidity introduced by treatment.
• Intercalation chemistry: DMSO, formamide, and potassium acetate can intercalate between layers (literature), enabling expanded gallery spacing and subsequent grafting or pillaring strategies.
• Filler and rheology modifier: controls viscosity and thixotropy in coatings and composites; in 3D-printing slurries and ceramic pastes, affects flow and green-body strength.
• Ceramic precursor: upon calcination to metakaolin and further heating, evolves to mullite, a critical phase for advanced ceramics.

Practical notes

• Drying: pre-dry at 105–120 °C to remove physisorbed water before adsorption/catalysis studies; higher-temperature calcination (450–600 °C) generates metakaolin with enhanced activity (literature).
• pH sensitivity: surface charge and dispersion state vary with pH—control carefully during adsorption isotherm measurements.
• Reusability: as a heterogeneous phase, can be separated by filtration/centrifugation; regenerate by washing and thermal treatment as appropriate to the immobilized species.

Reaction Conditions

Applicability note

• Kaolinite itself is inert under many conditions. Catalytic or support roles depend on pretreatment and immobilized species. The following are literature guidelines and not specifications for this item.

Representative literature conditions (not item-specific)

• Esterification (solid acid catalysis): acid-activated or calcined kaolinite, 1–20 wt% catalyst relative to reactants; temperatures 60–120 °C for lower alcohol–acid systems; solvent-free or toluene as azeotroping solvent; water removal enhances conversion.
• Transesterification (biodiesel model): metakaolin or sulfonated kaolin, 2–10 wt% catalyst; 50–65 °C (methanolysis of triglycerides); alcohol-to-oil molar ratios 6:1 to 12:1; 1–6 h, with stirring.
• Knoevenagel condensation: base- or acid-modified kaolinite, room temp to 80 °C; solvent-free grinding or ethanol/toluene media; catalytic loadings 5–15 mol% (as functional groups) reported.
• Adsorptive removal (batch isotherms): 0.1–10 g/L sorbent; pH tuned for target analyte; contact times 10–240 min with agitation; analyze via Langmuir/Freundlich fits.
• Catalyst supports: metal impregnation by incipient wetness using aqueous or alcoholic salt solutions; drying at 80–120 °C, calcination 300–500 °C; optional reduction (H2) 200–400 °C depending on metal.

Operational tips

• Control moisture history—pre-dry at 110 °C for 2–4 h before catalytic or adsorption experiments to improve reproducibility.
• Avoid high-ionic-strength media if stable dispersions are needed; add dispersants before powder addition.
• Verify structural integrity after harsh treatments using XRD (loss of 7.1 Å basal reflection indicates dehydroxylation to metakaolin).

Safety and Handling

Item-specific hazard information (from Product Data)

• GHS classification, signal word, pictograms, H-statements: Not specified for this item; refer to SDS.

General safety guidance for kaolinite/mineral powders (literature; not item-specific)

• Primary hazards: nuisance dust; mechanical irritation to eyes/skin; respiratory irritation from inhalable/respirable particulates. Handle powders to minimize dust generation.
• Peroxide formation: not applicable.
• Incompatibilities: strong acids/bases can alter surface chemistry and may dissolve aluminosilicate framework over time; avoid storing with reactive fluorides/HF (dissolves aluminosilicates). Avoid contact with strong oxidizers when organic contaminants are present.
• PPE: safety glasses, lab coat, and suitable gloves; use N95/P2 particulate respirator when dust cannot be controlled. Work in a fume hood or with local exhaust ventilation during transfers.
• First aid (general):
  • Inhalation: move to fresh air; seek medical attention if symptoms persist.
  • Eye contact: rinse cautiously with water for several minutes; remove contact lenses if present and easy.
  • Skin contact: wash with soap and water.
  • Ingestion: rinse mouth; seek advice if unwell.
• Environmental considerations: inert mineral; avoid release of fine particulates to drains/air.
• Storage conditions: keep container tightly closed; store dry to prevent agglomeration and microbial growth on adsorbed organics. Avoid humidity cycling which can change dispersion behavior.

Always consult the product-specific SDS for authoritative, current hazard and handling information.

Solvent Selection

Applicability note

• Kaolinite is a solid, inorganic, insoluble mineral. Traditional “solvent selection” for dissolution does not apply. Instead, consider dispersion media and slurry behavior relevant to your process.

Literature/general guidance on dispersion (not item-specific)

• Polarity: hydrophilic surfaces bearing silanol and aluminol groups; readily wets in water and polar protic solvents; poor affinity for nonpolar media unless surface-modified or with surfactants.
• Water: forms stable to semi-stable suspensions; stability depends on ionic strength, pH, and dispersants (e.g., sodium polyacrylate, sodium hexametaphosphate). Edge-site charge becomes positive at low pH and negative at high pH; electrostatic interactions control flocculation.
• Alcohols/glycols: dispersible as slurries; viscosity and hydrogen bonding influence aggregation.
• Nonpolar solvents (e.g., hexane, toluene): poor wetting/dispersion without surfactants or organo-modification.

Practical tips

• To minimize flocculation in water, use low ionic strength, adjust pH away from the isoelectric region (often > pH 6), and add a dispersant before powder addition while applying high-shear mixing or sonication.
• For organic-phase formulations, consider silane-treated/organophilic kaolin if strong compatibility with resins/oils is required; native kaolinite may require amphiphilic dispersants.
• Remove coarse agglomerates by sieving or low-speed centrifugation if a fine fraction is desired.

Comparison (literature)

• vs. Silica gel: higher acidity and surface area for silica; kaolinite is less acidic, less porous, and non-swelling.
• vs. Montmorillonite (smectite): smectites swell and have higher CEC; kaolinite is non-swelling with lower CEC but often better dimensional stability.

Storage and Reconstitution

Item-specific (from Product Data)

• Storage conditions: Not specified for this item; refer to CoA/Spec Sheet.
• Shipped in: Not specified for this item; refer to CoA/Spec Sheet.

General guidance (not item-specific)

• Storage: store at ambient temperature in a tightly closed container in a dry place. Use a desiccator or include a desiccant pouch to limit humidity uptake and agglomeration.
• Atmosphere: no special inert atmosphere required for native kaolinite; avoid corrosive vapors (strong acids/alkalis, HF) that can alter surface chemistry.
• Light sensitivity: not light sensitive.
• Reconstitution/dispersion: for preparing aqueous suspensions, pre-wet with a small amount of solvent (e.g., ethanol or water with dispersant) then dilute under high shear or sonication. Record solids loading, pH, and ionic strength for reproducibility.
• Shelf life: inorganic minerals are intrinsically stable; performance can drift due to moisture history or contamination. For critical uses, re-verify PSD, BET surface area, and pH of slurry at defined intervals.

Always consult the product’s CoA and SDS for item-specific storage and handling instructions.

Structure and Identity

Item-specific (from Product Data)

• Product name: Kaolinite (SKU: K485362)
• Grade: Native
• CAS: 1318-74-7
• Research use note: For research use only
• InChIKey: Not applicable to minerals; not provided for this item
• SMILES: Not applicable to minerals; not provided for this item

Literature/General identity (not item-specific)

• Mineral class: 1:1 phyllosilicate clay mineral of the kaolin group
• Idealized composition (literature): Al2Si2O5(OH)4
• Idealized formula weight (literature): ~258.16 g/mol
• Structure: layered sheets of SiO4 tetrahedra bonded to AlO6 octahedra (T–O layer). Each layer comprises a silica tetrahedral sheet hydrogen-bonded to an alumina octahedral sheet; layers stack via hydrogen bonding with minimal interlayer swelling.
• Functional motifs: surface silanol (Si–OH) and aluminol (Al–OH) groups; edge sites can be Brønsted-acidic or Lewis-acidic depending on pH and pretreatment.
• Polytypism: common polytypes include kaolinite-1Tc; stacking order affects basal spacing, typically d001 ≈ 7.1 Å (literature).

2D description in words (literature)

• Repeating hexagonal network of corner-sharing SiO4 tetrahedra fused to a sheet of edge-sharing AlO6 octahedra; charge-neutral layers stack along c with interlayer hydrogen bonds; external basal planes expose siloxane surfaces, while edges expose hydroxylated Al/Si sites.

Synthetic Utility

General (literature; not item-specific)

• Support for catalysts: kaolinite’s hydroxylated surface anchors metal ions/complexes and nanoparticles (e.g., Ni, Pd, Fe oxides) after ion exchange or grafting, providing heterogeneous catalysts for hydrogenation, oxidation, and coupling when properly engineered.
• Solid acid/base sites: native kaolinite exhibits weak Brønsted and Lewis acidity; acid activation or thermal treatment (metakaolin formation) enhances acidity and exposes new sites, enabling:
  • Esterification/transesterification
  • Dehydration of carbohydrates or alcohols (mild)
  • Aldol/Knoevenagel condensations under certain conditions
• Intercalation chemistry: intercalation with DMSO, formamide, or K-acetate expands basal spacing, permitting subsequent pillaring or functionalization to create tailored micro/mesoporosity.
• Adsorptive work-up: as an inexpensive, inert solid, kaolinite can be used for clarifying extracts, scavenging dyes or polar impurities, or moderating moisture in reactions and chromatography pre-treatments (less active than silica/alumina but more benign for acid-labile substrates).
• Ceramic/solid-state precursor: calcined kaolinite (metakaolin) reacts with alkali activators to form geopolymers; in materials synthesis, it serves as Al/Si source for zeolites (after dealumination/realumination steps).

Practical considerations

• Pre-dry or calcine to a defined thermal history; characterize acidity (e.g., NH3-TPD, pyridine-FTIR) if using as a catalyst.
• Particle size and dispersion influence mass transfer; optimize slurry solids and agitation.
• For sensitive organics, ensure absence of iron-rich impurities that could catalyze side reactions; if necessary, use high-purity or acid-washed material.

Target Specificity

Not applicable.

• This product is a mineral (kaolinite) and not a biological affinity reagent. There is no antigen/epitope or target binding specificity associated with this item.