{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,30]],"date-time":"2026-04-30T14:24:09Z","timestamp":1777559049530,"version":"3.51.4"},"reference-count":40,"publisher":"MDPI AG","issue":"9","license":[{"start":{"date-parts":[[2020,9,2]],"date-time":"2020-09-02T00:00:00Z","timestamp":1599004800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100001871","name":"Funda\u00e7\u00e3o para a Ci\u00eancia e a Tecnologia","doi-asserted-by":"publisher","award":["PTDC\/QUI-OUT\/31884\/2017"],"award-info":[{"award-number":["PTDC\/QUI-OUT\/31884\/2017"]}],"id":[{"id":"10.13039\/501100001871","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100001871","name":"Funda\u00e7\u00e3o para a Ci\u00eancia e a Tecnologia","doi-asserted-by":"publisher","award":["UIDB00102\/2020"],"award-info":[{"award-number":["UIDB00102\/2020"]}],"id":[{"id":"10.13039\/501100001871","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100001871","name":"Funda\u00e7\u00e3o para a Ci\u00eancia e a Tecnologia","doi-asserted-by":"publisher","award":["UID\/05488\/2018"],"award-info":[{"award-number":["UID\/05488\/2018"]}],"id":[{"id":"10.13039\/501100001871","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Minerals"],"abstract":"<jats:p>To allow the use of fibrous-like clays, as sepiolite, in different applications, their disaggregation and the formation of stable suspensions are crucial steps to enhance their performance significantly, e.g., in cellulose nanofibrils\/clay composite formulations, enabling an adequate mixture of the matrix and filler individual components. Three distinct physical treatments of dispersion (magnetic stirring, high-speed shearing, and ultrasonication) and four different chemical dispersants (polyacrylate, polyphosphate, carboxymethylcellulose, and alginate, all in the form of sodium salts) were tested to improve the dispersibility and the formation of stable suspensions of sepiolite. Two sepiolite samples from the same origin but with different pre-treatments were evaluated. The particle size and suspension stability were evaluated by dynamic light scattering, zeta potential measurements and optical microscopy. Additionally, the sepiolite samples were initially characterized for their mineralogical, chemical, and morphologic properties. Of the three physical dispersion treatments tested, the ultrasonicator typically produced more stable suspensions; on the other hand, the biopolymer carboxymethylcellulose showed a higher ability to produce stable suspensions, being, however, a smaller particle size obtained when polyphosphate was used. Remarkably, 47 out of 90 prepared suspensions of sepiolite stayed homogeneous for at least three months after their preparation. In sum, the combination of a high energy dispersing equipment with an appropriate dispersing agent led to stable suspensions with optimal properties to be used in different applications, like in the composite production.<\/jats:p>","DOI":"10.3390\/min10090779","type":"journal-article","created":{"date-parts":[[2020,9,3]],"date-time":"2020-09-03T08:40:26Z","timestamp":1599122426000},"page":"779","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":29,"title":["Improving Colloidal Stability of Sepiolite Suspensions: Effect of the Mechanical Disperser and Chemical Dispersant"],"prefix":"10.3390","volume":"10","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-4447-5107","authenticated-orcid":false,"given":"Lu\u00eds","family":"Alves","sequence":"first","affiliation":[{"name":"Department of Chemical Engineering, University of Coimbra, CIEPQPF, Rua S\u00edlvio Lima, P\u00f3lo II, PT-3030-790 Coimbra, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4717-6305","authenticated-orcid":false,"given":"Eduardo","family":"Ferraz","sequence":"additional","affiliation":[{"name":"Techn &amp; Art, Polytechnic Institute of Tomar, Quinta do Contador, Estrada da Serra, PT-2300-313 Tomar, Portugal"},{"name":"Geobiotec, Geosciences Department, Campus Universit\u00e1rio de Santiago, University of Aveiro, PT-3810-193 Aveiro, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4612-2519","authenticated-orcid":false,"given":"Julio","family":"Santar\u00e9n","sequence":"additional","affiliation":[{"name":"Tolsa, SA, Research &amp; Technology for New Businesses, Ctra. de Madrid a Rivas Jarama, 35, ES-28031 Madrid, Spain"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6084-4553","authenticated-orcid":false,"given":"Maria G.","family":"Rasteiro","sequence":"additional","affiliation":[{"name":"Department of Chemical Engineering, University of Coimbra, CIEPQPF, Rua S\u00edlvio Lima, P\u00f3lo II, PT-3030-790 Coimbra, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1474-767X","authenticated-orcid":false,"given":"Jos\u00e9 A. F.","family":"Gamelas","sequence":"additional","affiliation":[{"name":"Department of Chemical Engineering, University of Coimbra, CIEPQPF, Rua S\u00edlvio Lima, P\u00f3lo II, PT-3030-790 Coimbra, Portugal"}]}],"member":"1968","published-online":{"date-parts":[[2020,9,2]]},"reference":[{"key":"ref_1","first-page":"829","article-title":"Palygorskite and Sepiolite Group Minerals","volume":"Volume 1","author":"Dixon","year":"1989","journal-title":"Minerals in Soil Environments"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"3","DOI":"10.1016\/B978-0-444-53607-5.00001-3","article-title":"Chapter 1\u2014The Structures and Microtextures of the Palygorskite\u2014Sepiolite Group Minerals","volume":"Volume 3","author":"Singer","year":"2011","journal-title":"Developments in Clay Science"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"443","DOI":"10.1180\/claymin.1996.031.4.01","article-title":"Properties and applications of palygorskite-sepiolite clays","volume":"31","author":"Galan","year":"1996","journal-title":"Clay Miner."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"1392","DOI":"10.1016\/j.progpolymsci.2013.05.004","article-title":"Fibrous clays based bionanocomposites","volume":"38","author":"Darder","year":"2013","journal-title":"Prog. Polym. Sci."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"101994","DOI":"10.1016\/j.cis.2019.101994","article-title":"Composites of nanofibrillated cellulose with clay minerals: A review","volume":"272","author":"Alves","year":"2019","journal-title":"Adv. Colloid Interface Sci."},{"key":"ref_6","doi-asserted-by":"crossref","unstructured":"Wang, A., and Wang, W. (2019). 1\u2014Introduction. Nanomaterials from Clay Minerals, Elsevier.","DOI":"10.1016\/B978-0-12-814533-3.00001-6"},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"250","DOI":"10.1016\/j.ultsonch.2009.05.012","article-title":"Adsorption of methylene blue onto sonicated sepiolite from aqueous solutions","volume":"17","year":"2010","journal-title":"Ultrason. Sonochem."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"1303","DOI":"10.3762\/bjnano.10.129","article-title":"Multicomponent bionanocomposites based on clay nanoarchitectures for electrochemical devices","volume":"10","author":"Wicklein","year":"2019","journal-title":"Beilstein J. Nanotechnol."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"287","DOI":"10.1016\/j.jssc.2018.11.018","article-title":"Titanosilicate-sepiolite hybrid nanoarchitectures for hydrogen technologies applications","volume":"270","author":"Aranda","year":"2019","journal-title":"J. Solid State Chem."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"7","DOI":"10.1016\/S0378-5173(99)00075-7","article-title":"Pharmaceutical grade phyllosilicate dispersions: The influence of shear history on floc structure","volume":"182","author":"Viseras","year":"1999","journal-title":"Int. J. Pharm."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"118","DOI":"10.1016\/j.clay.2011.07.020","article-title":"Disaggregation of palygorskite crystal bundles via high-pressure homogenization","volume":"54","author":"Xu","year":"2011","journal-title":"Appl. Clay Sci."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"260","DOI":"10.1016\/j.compositesb.2012.05.034","article-title":"Effect of dispersion of sepiolite in sepiolite-NBR composite on the tensile strength","volume":"44","author":"Takei","year":"2013","journal-title":"Compos. Part B Eng."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"234","DOI":"10.1016\/j.clay.2017.03.032","article-title":"A new approch to sepiolite dispersion by treatment with ionic liquids","volume":"143","author":"Camilo","year":"2017","journal-title":"Appl. Clay Sci."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"3952","DOI":"10.1021\/la104410r","article-title":"Surface Modification of Sepiolite in Aqueous Gels by Using Methoxysilanes and Its Impact on the Nanofiber Dispersion Ability","volume":"27","author":"Benito","year":"2011","journal-title":"Langmuir"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"843","DOI":"10.1002\/pi.2016","article-title":"Synthesis and swelling behaviour of poly (sodium acrylate)\/sepiolite superabsorbent composites and nanocomposites","volume":"55","author":"Santiago","year":"2006","journal-title":"Polym. Int."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"42362","DOI":"10.1002\/app.42362","article-title":"Bionanocomposites based on polysaccharides and fibrous clays for packaging applications","volume":"133","author":"Darder","year":"2016","journal-title":"J. Appl. Polym. Sci."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"1933","DOI":"10.1016\/j.carbpol.2016.11.079","article-title":"Bionanocomposite foams based on the assembly of starch and alginate with sepiolite fibrous clay","volume":"157","author":"Darder","year":"2017","journal-title":"Carbohydr. Polym."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"1703048","DOI":"10.1002\/adfm.201703048","article-title":"Functional Hybrid Nanopaper by Assembling Nanofibers of Cellulose and Sepiolite","volume":"28","author":"Darder","year":"2018","journal-title":"Adv. Funct. Mater."},{"key":"ref_19","first-page":"3952","article-title":"A rheological grade sepiolite product and processes for its manufacture","volume":"27","year":"1990","journal-title":"Langmuir"},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"2275","DOI":"10.1080\/15275920701313616","article-title":"Zeta Potentials of Sepiolite Suspensions in Concentrated Monovalent Electrolytes","volume":"42","author":"Sabah","year":"2007","journal-title":"Sep. Sci. Technol."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"119","DOI":"10.1016\/S0040-6031(02)00228-9","article-title":"Controlled rate thermal analysis and differential scanning calorimetry of sepiolites and palygorskites","volume":"397","author":"Frost","year":"2003","journal-title":"Thermochim. Acta"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"423","DOI":"10.1007\/s10973-009-0321-z","article-title":"Controlled rate thermal analysis of sepiolite","volume":"98","author":"Frost","year":"2009","journal-title":"J. Therm. Anal. Calorim."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"285","DOI":"10.1346\/CCMN.1974.0220310","article-title":"On Dehydration of Bound Water of Sepiolite","volume":"22","author":"Nagata","year":"1974","journal-title":"Clays Clay Mineral."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"91","DOI":"10.2138\/am.2007.2134","article-title":"Synchrotron powder X-ray diffraction study of the structure and dehydration behavior of sepiolite","volume":"92","author":"Post","year":"2007","journal-title":"Am. Mineral."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1016\/S0924-2031(01)00110-2","article-title":"Near-infrared and mid-infrared spectroscopic study of sepiolites and palygorskites","volume":"27","author":"Frost","year":"2001","journal-title":"Vib. Spectrosc."},{"key":"ref_26","doi-asserted-by":"crossref","unstructured":"Farmer, V.C. (1974). The Infrared Spectra of Minerals, Mineralogical Society of Great Britain and Ireland.","DOI":"10.1180\/mono-4"},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"785","DOI":"10.1002\/cjce.20573","article-title":"Zeta potential study of natural- and acid-activated sepiolites in electrolyte solutions","volume":"90","author":"Dikmen","year":"2012","journal-title":"Can. J. Chem. Eng."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"240","DOI":"10.1016\/j.jcis.2004.08.036","article-title":"Electrokinetic properties of sepiolite suspensions in different electrolyte media","volume":"281","author":"Alkan","year":"2005","journal-title":"J. Colloid Interface Sci."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"18","DOI":"10.1016\/j.clay.2015.06.030","article-title":"Recent progress in dispersion of palygorskite crystal bundles for nanocomposites","volume":"119","author":"Wang","year":"2016","journal-title":"Appl. Clay Sci."},{"key":"ref_30","first-page":"147","article-title":"Measurement and application of zeta-potential","volume":"4","author":"Salopek","year":"1992","journal-title":"Rud. Geol. Naft. Zb."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"273","DOI":"10.1016\/j.foodhyd.2018.02.049","article-title":"Determination of the \u2018apparent pKa\u2019 of selected food hydrocolloids using ortho-toluidine blue","volume":"81","author":"Vleugels","year":"2018","journal-title":"Food Hydrocoll."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"543","DOI":"10.1007\/s10811-008-9317-5","article-title":"Some properties of alginate gels derived from algal sodium alginate","volume":"20","author":"Kakita","year":"2008","journal-title":"J. Appl. Phycol."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"1531","DOI":"10.1002\/pi.2943","article-title":"Relationship between the molecular structure of alginates and their gelation in acidic conditions","volume":"59","author":"Andriamanantoanina","year":"2010","journal-title":"Polym. Int."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"257","DOI":"10.1016\/j.colsurfa.2015.03.011","article-title":"On the role of hydrophobic interactions in cellulose dissolution and regeneration: Colloidal aggregates and molecular solutions","volume":"483","author":"Alves","year":"2015","journal-title":"Colloids Surf. A: Physicochem. Eng. Asp."},{"key":"ref_35","first-page":"5674","article-title":"Re-evaluation of phosphoric acid\u2013phosphates\u2014di-, tri- and polyphosphates (E 338\u2013341, E 343, E 450\u2013452) as food additives and the safety of proposed extension of use","volume":"17","author":"Younes","year":"2019","journal-title":"EFSA J."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"224002","DOI":"10.1088\/1361-648X\/ab724d","article-title":"Effect of sodium pyrophosphate and understanding microstructure of aqueous LAPONITE\u00ae dispersion using dissolution study","volume":"32","author":"Suman","year":"2020","journal-title":"J. Phys. Condens. Matter"},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"3285","DOI":"10.1007\/s00396-015-3715-4","article-title":"Rheology of polyacrylate systems depends strongly on architecture","volume":"293","author":"Alves","year":"2015","journal-title":"Colloid Polym. Sci."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"489","DOI":"10.1016\/j.jcis.2017.11.047","article-title":"On the rheology of mixed systems of hydrophobically modified polyacrylate microgels and surfactants: Role of the surfactant architecture","volume":"513","author":"Alves","year":"2018","journal-title":"J. Colloid Interface Sci."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"672562","DOI":"10.1155\/2012\/672562","article-title":"Computational Study of the Structure of a Sepiolite\/Thioindigo Mayan Pigment","volume":"2012","author":"Alvarado","year":"2012","journal-title":"Bioinorg. Chem. Appl."},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"22","DOI":"10.1016\/j.colsurfa.2012.04.018","article-title":"The anisotropic characteristics of natural fibrous sepiolite as revealed by contact angle, surface free energy, AFM and molecular dynamics simulation","volume":"408","author":"Benli","year":"2012","journal-title":"Colloids Surf. A: Physicochem. Eng. Asp."}],"container-title":["Minerals"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2075-163X\/10\/9\/779\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T10:06:05Z","timestamp":1760177165000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2075-163X\/10\/9\/779"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2020,9,2]]},"references-count":40,"journal-issue":{"issue":"9","published-online":{"date-parts":[[2020,9]]}},"alternative-id":["min10090779"],"URL":"https:\/\/doi.org\/10.3390\/min10090779","relation":{},"ISSN":["2075-163X"],"issn-type":[{"value":"2075-163X","type":"electronic"}],"subject":[],"published":{"date-parts":[[2020,9,2]]}}}