PMID- 33544605
OWN - NLM
STAT- PubMed-not-MEDLINE
LR  - 20210408
IS  - 1520-5827 (Electronic)
IS  - 0743-7463 (Print)
IS  - 0743-7463 (Linking)
VI  - 37
IP  - 7
DP  - 2021 Feb 23
TI  - On the Colloidal Behavior of Cellulose Nanocrystals as a Hydrophobization Reagent 
      for Mineral Particles.
PG  - 2322-2333
LID - 10.1021/acs.langmuir.0c03131 [doi]
AB  - In the search for more sustainable alternatives to the chemical reagents 
      currently used in froth flotation, the present work offers further insights into 
      the behavior of functionalized cellulose nanocrystals as mineral hydrophobization 
      agents. The study corroborates that hexylamine cellulose nanocrystals (HACs) are 
      an efficient collector for the flotation of quartz and also identifies some 
      particular characteristics as a result of their colloidal nature, as opposed to 
      the water-soluble reagents conventionally used. To investigate the individual and 
      collective effects of the frother and HACs on the attachment of particles and air 
      bubbles, an automated contact timer apparatus was used. This induction timer 
      measures particle-bubble attachment probabilities (P(att)) without the influence 
      of macroscopic factors present in typical flotation experiments. This allowed the 
      study of the combined influence of nanocellulose and frother concentration on 
      P(att) for the first time. While HACs readily adsorb on quartz modifying its 
      wettability, the presence of a frother leads to a drastic reduction in P(att) up 
      to 70%. The improved recovery of quartz in flotation cells might thus be 
      attributed to froth stabilization by HACs, perhaps acting as a Pickering foam 
      stabilizer. Among the main findings, a tendency of HACs to form mineral 
      agglomerates was identified and further explained using the extended DLVO theory 
      in combination with measured adsorption rates in a quartz crystal microbalance. 
      Therefore, this study distinguishes for the first time the antagonistic effect of 
      frothers on P(att) and their synergies with HACs on the stabilization of 
      orthokinetic froths through the hydrophobization mechanism unlike those of 
      typical water-soluble collectors.
FAU - Hartmann, Robert
AU  - Hartmann R
AUID- ORCID: 0000-0001-9126-8528
AD  - Department of Chemical and Metallurgical Engineering, School of Chemical 
      Engineering, Aalto University, P.O. Box 12200, Aalto 00076, Finland.
FAU - Rinne, Tommi
AU  - Rinne T
AD  - Department of Chemical and Metallurgical Engineering, School of Chemical 
      Engineering, Aalto University, P.O. Box 12200, Aalto 00076, Finland.
FAU - Serna-Guerrero, Rodrigo
AU  - Serna-Guerrero R
AD  - Department of Chemical and Metallurgical Engineering, School of Chemical 
      Engineering, Aalto University, P.O. Box 12200, Aalto 00076, Finland.
LA  - eng
PT  - Journal Article
DEP - 20210205
PL  - United States
TA  - Langmuir
JT  - Langmuir : the ACS journal of surfaces and colloids
JID - 9882736
SB  - IM
PMC - PMC8023700
COIS- The authors declare no competing financial interest.
EDAT- 2021/02/06 06:00
MHDA- 2021/02/06 06:01
PMCR- 2021/04/06
CRDT- 2021/02/05 17:09
PHST- 2021/02/06 06:00 [pubmed]
PHST- 2021/02/06 06:01 [medline]
PHST- 2021/02/05 17:09 [entrez]
PHST- 2021/04/06 00:00 [pmc-release]
AID - 10.1021/acs.langmuir.0c03131 [doi]
PST - ppublish
SO  - Langmuir. 2021 Feb 23;37(7):2322-2333. doi: 10.1021/acs.langmuir.0c03131. Epub 
      2021 Feb 5.