Fig 1 - uploaded by Jalal Hawari
Content may be subject to copyright.
![a Representative chemical structure of lignin modified from Suteu et al. [3]. b Schematic representation of grafting of lignin onto nanostructured silica SBA-15](profile/Jalal-Hawari/publication/257594244/figure/fig1/AS:668985385291791@1536509953540/a-Representative-chemical-structure-of-lignin-modified-from-Suteu-et-al-3-b-Schematic.png)
a Representative chemical structure of lignin modified from Suteu et al. [3]. b Schematic representation of grafting of lignin onto nanostructured silica SBA-15
Source publication
The slow decline in oil reserves with mounting oil prices is pushing industry to find more sustainable sources for industrial manufacturing. Lignin is the second most abundant natural renewable biopolymer that is underutilized and has many functional groups (–OH, phenolics) that make the biopolymer a convenient substrate for materials manufacturing...
Contexts in source publication
Context 1
... second most abundant natural bio- polymer (30 % of wood) after cellulose. It is produced in large quantities (more than 70 million tons/year) as waste from the pulp and paper and fuel production industries [1]. Lignin is a natural polymer possessing several functional groups including ether linkages, aliphatic and aromatic hydroxyl groups [2,3] (Fig. 1a), thereby rendering lignin a very attractive substrate as a macromonomer for the syn- thesis of biomaterials [1]. For example, lignin can be used as a filler to increase the green content of polymers, provided that its chemistry is well tuned for the targeted recipient. Lignin can also be used in the production of phenolic and epoxy ...
Context 2
... previous studies, grafting of lignin onto silica has not been investigated. Thus, the present paper describes a novel method to design lignin-based nano- composites by grafting lignin to silica surface. The method first included silylating lignin with triethoxychlorosilane followed by reacting silylated lignin with silanols of silica surface (Fig. 1b). In the present study we choose nano- structured silica SBA-15 (Santa Barbara amorphous 15) as a starting silica matrix mainly because of its high thermal and mechanical stabilities, high specific surface area (700-800 m 2 g -1 ) and relatively large pore diameter (*7-8 nm) to facilitate lignin incorporation onto silica [11,12]. The ...
Context 3
... all characteristic bands observed with lignin and SBA-15 [ Fig. 4a (A 1), (A 2)] before reaction appeared in the final product too [ Fig. 4a (A 3)], i.e. 1,500-1,600 cm -1 for the aromatic region and 2,800-3,000 cm -1 for C-H stretch- ing vibrations in lignin, and 1,000-1,200 cm -1 for Si-O-Si in ...
Similar publications
A novel N-substituted azaphosphatrane molecular precursor bearing an alkyne tether was synthesized using a multi-step strategy and covalently immobilized onto SBA-15 type silica through triazole linkages by means of the well-known click chemistry. The resulting hybrid material, [7]@SBA-15, was finely characterized by methods appropriate to molecula...
Citations
... Lignin is a component of wood that is obtained as a byproduct from pulp production and is mainly used as a fuel for power and heat generation (Sharma et al. 2021). The amount of lignin generated from the pulp industry is more than 70 million tonnes annually (Saad and Hawari 2013). It is, after cellulose, the second most abundant natural biopolymer, comprising 18-35 wt% of wood (Shorey et al. 2021). ...
Adsorption is a promising method to remove dyes, such as methylene blue, from wastewater. In this study, a dynamic adsorption set-up was used to treat synthetic wastewater containing methylene blue by using alkali-activated blast furnace slag and lignin composite foam. The structure of the foam without lignin was first optimized by comparing cationic and non-ionic surfactants in the preparation of the foam via the direct foaming method. The selection of the surfactant affects the porosity and pore structure of the foam through different abilities to stabilize the gas–liquid interface and changes in the viscosity of the fresh-state paste. The foam prepared with non-ionic Triton X-114 surfactant had the highest adsorption performance and was selected for the optimization of adsorption conditions. The optimized conditions were 5 mg/L influent concentration of methylene blue, pH of 7, and flow rate of 1.0 L/h (corresponding to ~ 9 min empty bed contact time). To further enhance the methylene blue adsorption performance, a composite containing lignin was prepared. The optimum lignin amount in the foam was 0.8 wt% and it resulted a ~ 93% higher adsorption amount compared to the foam without lignin. The highest cumulative adsorption capacity in this dynamic adsorption setup was 39.5 mg/g, which is among the highest reported values for methylene blue removal by monolithic adsorbents. The present study provides a proof of concept for the enhancement of adsorption performance of alkali-activated materials by introduction of lignin into the structure.
... The properties are greatly influenced by the biomass source and the pretreatment in isolating the product. Changes in the quantitative estimates of the lignin prepared by different fractions and the depolymerization effects can be studied effectively using the BET analysis [45]. The nitrogen adsorption and desorption isotherms in the BET analysis calculated the pore size and the surface area of the isolated kraft lignin to be 31.72 ...
Biobutanol is produced from the acetone-butanol-ethanol (ABE) fermentation. The major bottleneck of ABE fermentation is the self-inhibition of cells and the high energy consumption while recovering butanol. Several alternative techniques have been investigated, but the continuous recovery of butanol using the inexpensive and inert material could be a reliable choice. In the present study, the kraft lignin isolated from the novel lignocellulosic biomass, Sterculia foetida shells, was investigated for its selective adsorptive recovery of biobutanol from the simulated ABE solutions. SEM analyses of morphology and syringyl and guaiacyl units from FTIR show that the isolated lignin is in the softwood category. The XRD analysis shows 76.99% of the crystallinity index, which shows the crystalline features of kraft lignin. High thermal stability and surface area from TGA–DSC and BET analysis shows that the isolated lignin can be wisely used as an adsorbent. The isolated lignin maximum butanol adsorption capacity and the rate constant is 393.700 mg/g and 0.0954, respectively. The results show that Sterculia foetida lignin can be used commercially as a potential adsorbent for continuous biobutanol recovery in the ABE fermentation process. Using renewable lignin as an adsorbent is a sustainable approach for the circular bioeconomy as part of the lignocellulosic biorefinery. © 2023, The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.
... Lignin-Based Nanocomposites, Saad and Hawari (2013) biodegradability, low density, and surface active properties recruit them as a filler material (bio-filler) in the rubber industry. Further, the antibacterial experiments with lignin-based Ag nanocomposites witnessed the inhibitory effect against pathogenic gram-positive and gramnegative bacteria. ...
... Growing environmental concerns about their production and disposal of polymers (Jambeck et al., 2015;Miller, 2013) are driving a shift toward the development of new materials based on renewable resources (e.g., starch, lignin, and cellulose polymers), as well as the design of biodegradable, multifunctional and biocompatible polymers from natural macromolecule derivatives (Hauenstein et al., 2016;Mekonnen et al., 2013;Muthuraj and Mekonnen, 2018). Lignin is the second most abundant natural biopolymer after cellulose, constituting anywhere from 18 to 35 wt% of biomass, depending upon the feedstock type (Chakar and Ragauskas, 2004;Saad and Hawari, 2013;Silva et al., 2009). ...
Lignin being the second most abundant natural biopolymer after cellulose constitutes between 18 wt% and 35 wt % of wood. Due to its abundance, sustainability, renewability, and the ability to undergo numerous modifications through chemical reactions, there is a significant interest in lignin valorization for material applications. How-ever, its hydrophilicity, lack of melt processability, and poor dispersibility have hindered its wide scale appli-cation. Structural modifications have been reported to counter its detrimental properties effectively. Thus, in the present work, a novel silylation reaction was employed to successfully modify kraft lignin and enhance its hy-drophobicity. The modification was verified by using nuclear magnetic resonance and infrared spectroscopies. The change in the wettability and dispersibility in various solvent systems indicated the increase in hydropho-bicity due to the modifications. This enabled it to better disperse in natural rubber composites. Lignin being the hard moiety imparted mechanical strength, while, NR being the soft moiety, provided it with elastomeric characteristics in the composites. The incorporation of 5 wt% modified lignin in the hydrophobic NR matrix led to a 44.4% increase in the tensile strength. With higher loadings of filler in composites, an increase in elastic moduli and intensity of Payne effect were recorded. The hypothesized dispersibility improvement of the modified lignin in NR compared to its unmodified counterparts was also evident from the morphological analysis.
... 4). The strong absorbance at 3446, 1089, and 808 cm − 1 in the spectra of SBA-15, PMMA/SBA-15, PGMA/SBA-15, and PS/SBA-15 (Fig. 4a)can be attributed to stretching and bending vibrations of -OH, Si-O-Si, and Si-O, respectively, illuminating the presence of the SBA-15 framework[37]. The new peaks at 2953, 2926, 1731, and 1300 cm − 1 in the PMMA/SBA-15 spectrum(Fig. ...
Reversible addition fragmentation transfer (RAFT) polymerization has attracted much attention, because its reaction mechanism has been well studied and it provides a facile approach to prepare the special functional polymer. Herein, mesoporous SBA-15 with pore size of 6 nm was employed as a “microreactor” for the RAFT solution polymerization of methyl methacrylate (MMA), glycidyl methacrylate (GMA) or styrene (St) using a xanthate as a chain transfer agent and AIBN as the initiator. The structures, morphologies and properties of the obtained polymers and in-situ composites were fully characterized. XPS results confirm the presence of sulfur in the obtained polymers, which indicates a RAFT polymerization mechanism. XRD observation found that the in-situ composites exhibited the similar two-dimensional hexagonal pore structures intrinsic to SBA-15. However, the specific surface area, pore size, and pore volumes of the composites decreased dramatically compared with the intrinsic SBA-15 morphology. N2 adsorption studies of polymers synthesized from various monomer mixtures revealed differing properties with adsorption capacity in the order of GMA > MMA > St. The Mn and Mw of polymers produced from within SBA-15 were significantly higher than those produced external to the SBA-15 framework. Meanwhile, the molecular weight distributions of polymers constructed within the SBA-15 were narrower. Lastly, the thermal stability and glass transition temperature of the polymers constructed within the SBA-15 were notably enhanced.
... Up to now, the most reported studies on the preparation of LSNCs using alkali lignin were focused on multistep methods (Saad and Hawari, 2013;Klapiszewski et al., 2013;Jesionowski et al., 2014aJesionowski et al., , 2014bKlapiszewski et al., 2015aKlapiszewski et al., , 2015bXiong et al., 2015;Jedrzak et al., 2018). Typically the silica was first prepared and modified with expensive and toxic chemicals (e.g., tetraethoxysilane, nonylphenylpolyoxyethylene-glycol ethers, cyclohexane, unsaturated fatty alcohol). ...
... However, if the initial mass ratio of CHPTMAC to lignin reaches to 60 wt.% or even higher to 80 wt.%, we found that the prepared LSNCs based on these synthesized cationic lignins were also amorphous, while the surface of them were coated by many silica nanoparticles with particle size of ∼10 nm. Best of our knowledge, this special morphology of LSNCs has never been reported in the earlier published papers (Jesionowski et al., 2014a(Jesionowski et al., , 2014bKlapiszewski et al., 2015aKlapiszewski et al., , 2015bXiong et al., 2017;Jedrzak et al., 2018;Qu et al., 2010;Zhang et al., 2013;Tian et al., 2017;Saad and Hawari, 2013;Klapiszewski et al., 2013;Budnyak et al., 2018). The difference in the surface composition of LSNCs will lead to different physicochemical properties for LSNCs, which helps select the appropriate application fields for LSNCs. ...
... This meant that it was impracticable to prepare uniform LSNCs by the co-precipitation of KL and sodium metasilicate in aqueous solution. The similar phenomenon also had been found by Saad and Hawari (Saad and Hawari, 2013). The main reason was that the interaction between KL and precipitated silica was too weak and the KL molecules were extremely easy to form agglomerates during acid precipitation. ...
In this work, cationic lignin derivatives were synthesized by grafting reaction of lignin and 3-chloro-2-hydro-xypropyltrimethylammonium chloride. Then the synthesized cationic lignins were used to prepare lignin/silica nanocomposites (LSNCs) via a green co-precipitation method. The following characterizations, particle size distribution, SEM, TEM, XRD, FT-IR, XPS, static contact angle, specific surface area, and pore size distribution, were employed to understand the dispersity, morphology, crystal structure, and textural property of different LSNCs. The results showed that lignin with low content of cationic quaternary ammonium (QA) groups couldn't support the formation of uniform LSNCs, while lignin with moderate content of QA groups leaded to the formation of uniform LSNCs with a core-shell structure, lignin/silica hybrids in inner side and thin layer of lignin on surface. When the content of QA groups in lignin was high, the prepared LSNCs presented porous strawberry-like structure, lignin/silica hybrids at inside and coating layer of silica nanoparticles within 10 nm on surface.
... Although the worldwide total energy demand has grown 24% from 2005 to 2015, the bioenergy portion in overall global primary energy utilization has stayed comparatively stable (about 10%). The annual production of lignin in large quantities is more than 70 million tons, but only 2% of lignin is applied for industrial purposes, and 95% is burnt to produce energy (Saad and Hawari, 2013;Lora et al., 2002). This is while 80% of the world's primary energy supply is still from fossil fuels (Sieminski, 2014). ...
... Some conclusions about interactions of silica with lignin can be obtained from the paper on the grafting of lignin onto nanostructured silica [116]. Lignin has many functional groups (-OH, phenolics) which makes this biopolymer a convenient substrate for materials manufacturing in the industry. ...
This chapter contains sections titled: Introduction An Overview of Compounds and Natural Minerals Containing the Element Si, which are the Most Relevant in the Science and Technology of Lignocellulosics Si‐containing Compounds in Adhesives and in Lignocellulosic Substrates and their Influence on the Performance of Adhesive Bonds Interactions of the Si Compounds with Lignocellulosics Wood‐ and Lignocellulose‐based Composites Containing Si Compounds Summary and General Remarks Acknowledgments
... [25,26] As ar esult of high lignin and ashc ontent, the husks are not av iable animal feed, [27] but they can be burnt to yield large quantitieso fs ilica that can be used in an umber of materiala pplications. [25,[27][28][29][30][31][32][33] However,c ompared to the relatively well-valorized polysaccharide fractionsa nd processing of rice husk-derived silica, little attention hasb een paid to the abundant lignin fractionfrom rice husks. ...
Chemically modified lignins are important for the generation of biomass‐derived materials and as precursors to renewable aromatic monomers. A butanol‐based organosolv pretreatment has been used to convert an abundant agricultural waste product, rice husks, into a cellulose pulp and three additional product streams. One of these streams, a butanol‐modified lignin, was oxidized at the γ position to give a carboxylic acid functionalized material. Subsequent coupling of the acid with aniline aided lignin characterization and served as an example of the flexibility of this approach for grafting side chains onto a lignin core structure. The pretreatment was scaled up for use on a multi‐kilogram scale, a development that enabled the isolation of an anomeric mixture of butoxylated xylose in high purity. The robust and scalable butanosolv pretreatment has been developed further and demonstrates considerable potential for the processing of rice husks.
... Lignin has a critical effect on increasing the amount of liquid transportation fuel accessible from biomass over the carbohydrate particles [4]. The annual production of lignin in large quantities is more than 70 million tons but only 2% of lignin is applied for industrial purposes and 95% is burnt to produce energy [9,10]. This is while 80% of world's primary energy supply is still from fossil fuels [11]. ...
The purified lignin extracted from wheat straw by organosolv process was characterized for the existence of lignin subunits, functional groups and physical and thermal behaviours. Presence of carboxyl, hydroxyl, methoxyl groups and C–C, C–O, C=O linkages were conducted by Fourier Transform Infrared (FT-IR). By ¹H-NMR (Nuclear Magnetic Resonance Spectroscopy) presence of aromatic protons, phenolic hydroxyls, carboxylic acids, and aldehydes were established. Moreover, ¹³C-NMR spectra have disclosed the presence of condensed and uncondensed aliphatic and aromatic aryls and ethers. The existence of syringyl and guaiacyl units also were confirmed with both FTIR and NMR spectroscopies. Furthermore, the results from Thermal Gravimetric Analysis (TGA) showed the weight of extracted lignin is changed in temperatures between 180 and 670 °C by devolatization, formation and condensation of different chemicals. Also, the Differential Scanning Calorimetry (DSC) graph displayed a glass transition temperature of 105 °C for extracted lignin. As a result, the extracted lignin with high purity can be a suitable candidate for carrying out value-added products.
