Rahman Hafizur, An Siwen, Norlin Börje, Persson Erik, Engstrand Per, Zeeshan Faisal, Granfeldt Thomas, Slavíček Tomáš, Pettersson Gunilla
Mid Sweden University, Holmgatan 10, 851 70 Sundsvall, Sweden.
MAX IV Laboratory, Lund University, 225 91 Lund, Sweden.
ACS Omega. 2022 Dec 15;7(51):48555-48563. doi: 10.1021/acsomega.2c07086. eCollection 2022 Dec 27.
Minimizing the fiber property distribution would have the potential to improve the pulp properties and the process efficiency of chemimechanical pulp. To achieve this, it is essential to improve the level of knowledge of how evenly distributed the sulfonate concentration is between the individual chemimechanical pulp fibers. Due to the variation in quality between pulpwood and sawmill chips, as well as the on-chip screening method, it is difficult to develop an impregnation system that ensures the even distribution of sodium sulfite (NaSO) impregnation liquid. It is, therefore, crucial to measure the distribution of sulfonate groups within wood chips and fibers on a microscale. Typically, the degree of unevenness, i.e., the amount of fiber sulfonation and softening prior to defibration, is unknown on a microlevel due to excessively robust or complex processing methods. The degree of sulfonation at the fiber level can be determined by measuring the distribution of elemental sulfur and counterions of sulfonate groups, such as sodium or calcium. A miniaturized energy-dispersive X-ray fluorescence (ED-XRF) method has been developed to address this issue, enabling the analysis of sulfur distributions. It is effective enough to be applied to industrial laboratories for further development, i.e., improved image resolution and measurement time.
