Self-assembly of colloidal lignin particles in a continuous flow tubular reactor

Rahul Bangalore Ashok, Yao Xiao, Kalle Lintinen, Pekka Oinas, Mauri Kostiainen, Monika Österberg

Research output: Contribution to journalArticleScientificpeer-review

19 Citations (Scopus)
77 Downloads (Pure)


A scalable tubular flow reactor was designed and developed for the continuous formation of colloidal lignin particles (CLPs). The reactor consists of a series of tubes, inside which many static mixing elements are equipped to aid in the formation of a homogeneous dispersion of CLPs. The colloids were formed instantaneously through self-assembly upon the addition of the lignin solution into water. The effects of flowrate, length of the tubes and static mixing elements on the particle size, stability and CLP yield after drying were determined. It was found that a higher flowrate of lignin solution within the testing range of 32-240 mL/min resulted in smaller sized CLPs. Optimizations of the mixing length and the static mixing elements to 3 m and at least 1 m, respectively, could ensure an efficient mixing, thus resulting in CLP dispersions with smaller size of lignin particles (200 nm – 400 nm) and high lignin concentrations (up to 2.8 wt. %) along with yields up to 95 %. The TEM images indicated that the formed colloids are composed of lignin particles of regular sphere shape and with good stability. The tubular reactor offers better control of particle size which ensures the formation of colloidal dispersions with narrower particle size distribution in comparison to a stirred mixer reactor. Furthermore, using a tubular reactor enables the continuous production of CLPs, making it suitable for scale up and industrial applications.
Original languageEnglish
Article number124228
Number of pages7
JournalColloids and Surfaces A: Physicochemical and Engineering Aspects
Publication statusPublished - 20 Feb 2020
MoE publication typeA1 Journal article-refereed


Dive into the research topics of 'Self-assembly of colloidal lignin particles in a continuous flow tubular reactor'. Together they form a unique fingerprint.

Cite this