Nora Jullok, Assoc. Prof. Dr.This page provides access to scholarly publication by UniMAP Faculty members and researchershttp://dspace.unimap.edu.my:80/xmlui/handle/123456789/391782024-03-28T19:27:31Z2024-03-28T19:27:31ZA Green Approach to Modify Surface Properties of Polyurethane Foam for Enhanced Oil AbsorptionZhi, Chien NgRosyiela Azwa, RoslanWoei, Jye LauGürsoy, MehmetMustafa, KaramanNora, JullokAhmad Fauzi, Ismailhttp://dspace.unimap.edu.my:80/xmlui/handle/123456789/687212020-11-13T03:37:01Z2020-08-01T00:00:00ZA Green Approach to Modify Surface Properties of Polyurethane Foam for Enhanced Oil Absorption
Zhi, Chien Ng; Rosyiela Azwa, Roslan; Woei, Jye Lau; Gürsoy, Mehmet; Mustafa, Karaman; Nora, Jullok; Ahmad Fauzi, Ismail
The non-selective property of conventional polyurethane (PU) foam tends to lower its oil absorption efficiency. To address this issue, we modified the surface properties of PU foam using a rapid solvent-free surface functionalization approach based on the chemical vapor deposition (CVD) method to establish an extremely thin yet uniform coating layer to improve foam performance. The PU foam was respectively functionalized using different monomers, i.e., perfluorodecyl acrylate (PFDA), 2,2,3,4,4,4-hexafluorobutyl acrylate (HFBA), and hexamethyldisiloxane (HMDSO), and the effect of deposition times (1, 5 and 10 min) on the properties of foam was investigated. The results showed that all the modified foams demonstrated a much higher water contact angle (i.e., greater hydrophobicity) and greater absorption capacities compared to the control PU foam. This is due to the presence of specific functional groups, e.g., fluorine (F) and silane (Si) in the modified PU foams. Of all,
the PU/PHFBAi foam exhibited the highest absorption capacities, recording 66.68, 58.15, 53.70, and 58.38 g/g for chloroform, acetone, cyclohexane, and edible oil, respectively. These values were 39.19–119.31% higher than that of control foam. The promising performance of the PU/PHFBAi foam is due to the improved surface hydrophobicity attributed to the original perfluoroalkyl moieties of the HFBA monomer. The PU/PHFBAi foam also demonstrated a much more stable absorption
performance compared to the control foam when both samples were reused for up to 10 cycles. This clearly indicates the positive impact of the proposed functionalization method in improving PU properties for oil absorption processes.
Link to publisher's homepage at https://www.mdpi.com/
2020-08-01T00:00:00ZP-recovery as calcium phosphate from wastewater using an integrated selectrodialysis/crystallization processAnh T.K., TranYang ZhangDominik, De CorteJan-Bart, HannesWenyuan YePriyanka, MondalNora, JullokBoudewijn, MeesschaertLuc PinoyBart Van der, Bruggenhttp://dspace.unimap.edu.my:80/xmlui/handle/123456789/357192014-06-19T09:03:40Z2014-01-01T00:00:00ZP-recovery as calcium phosphate from wastewater using an integrated selectrodialysis/crystallization process
Anh T.K., Tran; Yang Zhang; Dominik, De Corte; Jan-Bart, Hannes; Wenyuan Ye; Priyanka, Mondal; Nora, Jullok; Boudewijn, Meesschaert; Luc Pinoy; Bart Van der, Bruggen
A promising and sustainable renewable source of phosphate was obtained through crystallization of calcium phosphate from wastewater. The aim of the present study was to evaluate the feasibility of an integrated selectrodialysis/crystallization process to recover phosphate, in which selectrodialysis was first used to pre-concentrate the phosphate before crystallization in a pellet reactor. The results of selectrodialysis show that an increase in current density, initial pH of the product, and initial feed concentration of phosphate led to an increase in phosphate concentration in the product. The desalination efficiency from wastewater was 87%, the phosphate concentration in the product can reach 16 mM with a purity of 44%, the current efficiency to transport phosphate and chloride was 26.6% for standard anion exchange membrane and 63% for monovalent selective anion exchange membrane. The optimal operational conditions for phosphate recovery with a pellet reactor were examined by changing the initial concentration, the pH and the superficial velocity. A precipitation efficiency of 82.7% of phosphate was achieved at pH 11, an inlet concentration of phosphates of 2.5 mM, a Ca/P molar ratio of 1.5 and a superficial velocity of 61 m/h. From the results, it can be concluded that the pellet reactor combined with selectrodialysis is an appropriate method to recover phosphate from wastewater as calcium phosphate, which is not only technically but also environmentally feasible, reducing water pollution, preventing eutrophication and yielding valuable and sustainable resources.
Link to publisher's homepage at http://www.journals.elsevier.com
2014-01-01T00:00:00ZPellet reactor pretreatment: A feasible method to reduce scaling in bipolar membrane electrodialysisTran, Anh Thu KNora, JullokMeesschaert, Boudewijn D.Pinoy, Luc Jozef JanVan Der Bruggen, Barthttp://dspace.unimap.edu.my:80/xmlui/handle/123456789/356052014-06-17T08:20:31Z2013-07-01T00:00:00ZPellet reactor pretreatment: A feasible method to reduce scaling in bipolar membrane electrodialysis
Tran, Anh Thu K; Nora, Jullok; Meesschaert, Boudewijn D.; Pinoy, Luc Jozef Jan; Van Der Bruggen, Bart
This study aims to evaluate the feasibility of a pellet reactor in reducing the scaling potential in electrodialysis with bipolar membranes for water containing a high concentration of calcium by adding sodium carbonate to precipitate carbonate as calcium carbonate on granular seed material. The optimized operating condition obtained at pH 11.1, and a ratio of [CO32-]:[Ca2+]=1.2:1 enabled to obtain 90% efficiency of calcium removal from real water. The efficiency of scaling potential removal was validated by comparing the scaling level on the membrane surface of two electrodialysis batches of a washing water, with and without pretreatment. For the latter, scalants were found at both sides of the cation exchange membrane (FKB), diluate and base sides, identified as calcium and magnesium precipitates. Furthermore, there was also a severe scaling effect at the base side of the bipolar membrane (FBM). However, a different observation was found for the pretreated water. SEM and elemental analysis for both FKB and FBM membranes demonstrated less scaling on both membrane surfaces.
Link to publisher's homepage at http://www.elsevier.com/
2013-07-01T00:00:00ZPotential innovations in separation technology by nature-inspired membranes: Beneath and beyond the Earth's crustNora, Jullokhttp://dspace.unimap.edu.my:80/xmlui/handle/123456789/351082014-06-05T03:56:43Z2014-04-01T00:00:00ZPotential innovations in separation technology by nature-inspired membranes: Beneath and beyond the Earth's crust
Nora, Jullok
The understanding of complex bio-mechanisms in nature is explored in this perspective as a way to effectively enable scientific advancements in membrane technology. The mechanisms of nature-inspired technological improvements are first analyzed from macroscale to nanoscale. Separation methods using membranes can be related to natural separation mechanisms such as soil filtration, when the production of groundwater is considered. Innovative nature-inspired mechanisms are presented, which include ideas in developing new methods for membrane synthesis in order to boost the vast range of applications of membrane separation processes. Future innovative applications discussed in this paper include nanoscale surface patterning, self-organization, and the control of these processes. Improvements to existing membranes through the resemblance of natural mechanisms are also aimed towards realizing sustainable and cost-effective systems
Link to publisher's homepage at http://onlinelibrary.wiley.com
2014-04-01T00:00:00Z