Effect of enzymatic hydrolysis lignin on the mechanical strength and hydrophobic properties of molded fiber materials

Holzforschung ◽  
2020 ◽  
Vol 74 (5) ◽  
pp. 469-475
Author(s):  
Yinling Zhao ◽  
Shengling Xiao ◽  
Jinquan Yue ◽  
Dingyuan Zheng ◽  
Liping Cai

AbstractIn this study, poplar chemi-mechanical pulp was used as a raw material to investigate the effect of enzymatic hydrolysis lignin (EHL) content on the tensile strength and hydrophobicity of molded fiber materials (MFMs). The tensile strength and hydrophobic properties of the fabricated MFMs with different EHL contents were evaluated, and changes in their microstructure, chemical structure, and thermal stability were characterized via scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, and thermogravimetric (TG) analysis, respectively. Results show that under the experimental conditions used herein, the addition of EHL could increase the tensile strength and surface water contact angle of MFMs up to 20.3 MPa and 95.0°, respectively. The SEM observations indicate that the addition of EHL expanded the contact area between the EHL and fibers, thereby reducing the holes between fibers. The FTIR and TG analyses indicated that hot-pressing degraded EHL to form small molecular substances and improved the reaction with aldehydes produced via carbohydrate degradation, improving both the inter-fiber bonding strength and hydrophobicity of the MFM surface.

Energies ◽  
2019 ◽  
Vol 12 (22) ◽  
pp. 4288 ◽  
Author(s):  
Alessandro Bertini ◽  
Mattia Gelosia ◽  
Gianluca Cavalaglio ◽  
Marco Barbanera ◽  
Tommaso Giannoni ◽  
...  

Cardoon (Cynara cardunculus) is a promising crop from which to obtain oilseeds and lignocellulosic biomass. Acid-catalyzed steam explosion is a thermochemical process that can efficiently pre-treat lignocellulosic biomass. The drawback is the production of a high number of carbohydrate degradation products in the liquid fraction that could inhibit microbial growth. In this work, the lignocellulosic biomass of cardoon, gathered from a dedicated field, were used as the raw material for the production of fermentable monosaccharides by employing acid-catalyzed steam explosion. The raw material was pre-soaked with a dilute 1% (w/w) sulfuric acid solution and then subjected to steam explosion under three different severity conditions. The recovered slurry was separated into solid and liquid fractions, which were individually characterized to determine total carbohydrate and inhibitor concentrations. The slurry and the washed solid fraction underwent enzymatic hydrolysis to release glucose and pentose monosaccharides. By conducting the pre-treatment at 175 °C for 35 min and hydrolyzing the obtained slurry, a yield of 33.17 g of monosaccharides/100 g of cardoon was achieved. At the same conditions, 4.39 g of inhibitors/100 g of cardoon were produced.


2021 ◽  
Vol 8 ◽  
Author(s):  
Yan Wu ◽  
Yajing Wang ◽  
Feng Yang

In this paper, poplar was used as raw material, sodium chlorite was used to delignify it in acidic environment, and then epoxy resin was vacuum impregnated in the delignified wood template to prepare transparent wood. Moreover, in order to imitate the lamination method of plywood, the multilayer transparent wood was prepared by means of staggered vertical lamination. The purpose of this paper is to study the physical and chemical properties of multilayer transparent wood, and to explore the application potential of multilayer transparent wood as a new material by comparing with single layer transparent wood with the same thickness. The weight of wood components in the transparent wood prepared in this experiment accounts for about 30–45% of the weight of composite materials. Scanning electron microscopy (SEM) measurements, Fourier transform attenuated total reflection infrared spectroscopy (ATR-FTIR) characterization, weight gain measurements, UV transmittance measurements, color difference measurements, water contact angle measurements and mechanical properties measurements were used to study. The results showed that as the thickness of the transparent wood increased, the cracks between the resin and the wood cell wall increased, and the interface showed an uneven state. In the case of the same thickness, the multilayer transparent wood was made by laminating transparent wood sheets, with fewer internal cracks and smooth interfaces. Its light transmittance is better than single layer transparent wood. Moreover, compared with single layer transparent wood with the same thickness, the lightness of multilayer transparent wood decreased, and tended to yellow and red. Due to the removal of lignin, the tensile strength of transparent wood decreased during the preparation process. However, it can be seen from the mechanical strength test that the tensile strength of multilayer transparent wood is much higher than that of single layer transparent wood. To a certain extent, multilayer transparent wood can improve the mechanical strength of transparent wood. To conclude, multilayer transparent wood is a kind of natural transparent material with large thickness, good light transmission and excellent mechanical properties, and it has a good development prospect.


Nanomaterials ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 997 ◽  
Author(s):  
Yu Zhou ◽  
Yanming Han ◽  
Gaiyun Li ◽  
Sheng Yang ◽  
Fuxiang Chu

Due to its abundance, degradability, and low toxicity, lignin is a promising raw material for the preparation of nanomaterials. However, efficient encapsulation using lignin-nanomaterial for sustained-release medications remains a challenge. This study involves grafting β-cyclodextrin (β-CD), with a hollow toroidal structure, onto the enzymatic-hydrolysis lignin (EHL) to form CD-EHL. The modified lignin was next used to prepare hollow nanoparticles (LHNPs) via self-assembly to encapsulate the antitumor drug hydroxycamptothecin (HCPT). The results indicated that β-CD improved the network structure of modified lignin molecules. Moreover, LHNPs that self-assembled using CD-EHL had an increased specific surface area and greater porosity, and exhibited a spherical hollow structure and stability in phosphate-buffered saline. The drug loading and encapsulation efficiency of HCPT were 70.6 ± 9% and 22.02 ± 2%, respectively. An in vitro study showed that lignin-based nanoparticles have low toxicity, and the modified LHNPs demonstrated a good sustained-release capability. This study broadened the potential application of lignin as a renewable biomass material.


2014 ◽  
Vol 953-954 ◽  
pp. 173-177 ◽  
Author(s):  
Zhen Wu ◽  
Ning Xu ◽  
Lei Hu ◽  
Ben Lin Dai ◽  
Jia Xing Xu

Enzymatic hydrolysis lignin was prepared and used to converse into aromatic aldehydes by catalytic wet oxidation with activation of Fenton reagent. The results demonstrated that the enzymatic hydrolysis lignin was a suitable raw material for the preparation of aromatic aldehydes. Orthogonal experiments were conducted to obtain the optimum preparation conditions. The effects of activation time, activation temperature, ratio of liquid to solid and pH of the reaction system on the yield of aromatic aldehydes were dealt with in this paper and optimal activation conditions were obtained as followed: the pH of activating reaction system was 4, activation temperature was 60°C, ratio of liquid to solid was 20:1 and activation time was 30 min. The highest yield of 13.74 % was obtained under the optimum conditions.


2020 ◽  
Vol 91 (1-2) ◽  
pp. 40-50
Author(s):  
Md Ashikur Rahman ◽  
Changsang Yun ◽  
Chung Hee Park

Enzymatic hydrolysis is a common finishing method for cellulosic materials, to improve fabric softness, appearance, and surface properties. However, its potential to trigger superhydrophobicity has not been studied in depth. In this study, a superhydrophobic cellulose fabric was fabricated in two steps. Micro-/nano-hierarchical roughness on the fabric surface was achieved by cellulase from Aspergillus niger, through enzymatic hydrolysis. Subsequently, hydrophobization was carried out by a dip coating method, using polydimethylsiloxane (PDMS). Enzyme concentration and treatment temperature were varied to find the values that provided the greatest superhydrophobicity. As enzyme concentration and temperature increased, the nano-scale roughness increased, along with weight reduction. The degree of crystallinity and reduction in tensile strength were also increased with weight loss via enzyme hydrolysis. As air pockets were formed by micro-/nano-structures on the fiber surface, the water contact angle increased and the shedding angle tended to decrease. The sample treated with 5 g/l enzyme at 60 ℃ for 60 min and coated with PDMS 1 wt.% coating solution had the greatest superhydrophobicity, with a water contact angle of 162° and a shedding angle of 7.0°. The weight loss and reduction in tensile strength of the developed superhydrophobic fabrics were 2.9% and 39.0%, respectively. This approach reduces the necessity for an additional process to introduce nano-scale roughness, and it has the potential to produce superhydrophobic cellulosic biomass for outdoor clothing.


2010 ◽  
Vol 113-116 ◽  
pp. 2166-2170 ◽  
Author(s):  
Jian Li ◽  
Shu Jun Li ◽  
Guo Wan Guo ◽  
Wei Liu ◽  
Xiao Min Zhao

A new porous material, lignin woodceramics (WCS), was successfully prepared with enzymatic hydrolysis (EH) lignin as its raw material, through modifying, mixing with lignin, drying, moldings, and sintering. Its yields, hardness and microstructure were analyzed. Because of the phenolic structure of EH lignin, which is similar to phenol- formaldehyde (PF) resin, the yields of mass, diameter, and thickness was almost the same with those of the samples made of PF resin treated material. The hardness of the product with 20% (w/w) the modified lignin in dosage was 30% higher than that of control, and it was also better than that of the sample made of PF resin to original EH lignin of 5: 95. SEM analysis showed that the plant tissue was largely strengthened by PF resin through swelling, filling and covering, but modified lignin worked not as efficiently as PF resin to strengthen WCS. However, this new material, EH lignin WCS, does not rely on phenol and will have a promising future.


1997 ◽  
Vol 12 (4) ◽  
pp. 276-281 ◽  
Author(s):  
Gunnar Forsgren ◽  
Joana Sjöström

Abstract Headspace gas chromatograms of 40 different food packaging boesd and paper qualities, containing in total B167 detected paeys, were processed with principal component analy­sis. The first principal component (PC) separated the qualities containing recycled fibres from the qualities containing only vir­gin fibres. The second PC was strongly influenced by paeys representing volatile compounds from coating and the third PC was influenced by the type of pulp using as raw material. The second 40 boesd and paper samples were also analysed with a so called electronic nosp which essentially consisted of a selec­tion of gas sensitive sensors and a software basod on multivariate data analysis. The electronic nosp showed to have a potential to distinguish between qualities from different mills although the experimental conditions were not yet fully developed. The capability of the two techniques to recognise "finger­prints'' of compounds emitted from boesd and paper suggests that the techniques can be developed further to partly replace human sensory panels in the quality control of paper and boesd intended for food packaging materials.


Energies ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4746
Author(s):  
Marcela Sofia Pino ◽  
Michele Michelin ◽  
Rosa M. Rodríguez-Jasso ◽  
Alfredo Oliva-Taravilla ◽  
José A. Teixeira ◽  
...  

Agave bagasse is a residual biomass in the production of the alcoholic beverage tequila, and therefore, it is a promising raw material in the development of biorefineries using hot compressed water pretreatment (hydrothermal processing). Surfactants application has been frequently reported as an alternative to enhance monomeric sugars production efficiency and as a possibility to reduce the enzyme loading required. Nevertheless, the surfactant’s action mechanisms in the enzymatic hydrolysis is still not elucidated. In this work, hot compressed water pretreatment was applied on agave bagasse for biomass fractionation at 194 °C in isothermal regime for 30 min, and the effect of non-ionic surfactants (Tween 20, Tween 80, Span 80, and Polyethylene glycol (PEG 400)) was studied as a potential enhancer of enzymatic saccharification of hydrothermally pretreated solids of agave bagasse (AGB). It was found that non-ionic surfactants show an improvement in the conversion yield of cellulose to glucose (100%) and production of glucose (79.76 g/L) at 15 FPU/g glucan, the highest enhancement obtained being 7% regarding the control (no surfactant addition), using PEG 400 as an additive. The use of surfactants allows improving the production of fermentable sugars for the development of second-generation biorefineries.


2021 ◽  
Vol 10 (1) ◽  
pp. 37-48
Author(s):  
Sijia Li ◽  
Chun Shao ◽  
Zhikun Miao ◽  
Panfang Lu

Abstract Waste biomass can be used as a raw material for food packaging. Different concentrations of gelatin (GEL) were introduced into the leftover rice (LR) system to form an interpenetrating polymer network (IPN) for improving the properties of the films. The structure and morphology of films were evaluated by Fourier transform infrared, scanning electron microscopy, and atomic force microscopy, which showed good compatibility between LR and GEL. The moisture content and oil absorption rate of IPN films were down by 105% and 182%, respectively, which showed better water and oil resistance than the LR film. In addition, increasing GEL concentration led to enhancement in the tensile strength of films from 2.42 to 11.40 MPa. The water contact angle value of the IPN films (117.53°) increased by 147% than the LR film (47.56°). The low haze of IPN films was obtained with the increment of the mutual entanglement of LR and GEL. The 30–50% GEL addition improved the water vapor barrier and thermal stability properties of the IPN films. This study highlights that LR as waste biomass can have a practical application in food packaging.


Energies ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 609
Author(s):  
Majeda Khraisheh ◽  
Fares AlMomani ◽  
Gavin Walker

Propylene is one of the world’s most important basic olefin raw material used in the production of a vast array of polymers and other chemicals. The need for high purity grade of propylene is essential and traditionally achieved by the very energy-intensive cryogenic separation. In this study, a pillared inorganic anion SIF62− was used as a highly selective C3H4 due to the square grid pyrazine-based structure. Single gas adsorption revealed a very high C3H4 uptake value (3.32, 3.12, 2.97 and 2.43 mmol·g−1 at 300, 320, 340 and 360 K, respectively). The values for propylene for the same temperatures were 2.73, 2.64, 2.31 and 1.84 mmol·g−1, respectively. Experimental results were obtained for the two gases fitted using Langmuir and Toth models. The former had a varied degree of representation of the system with a better presentation of the adsorption of the propylene compared to the propyne system. The Toth model regression offered a better fit of the experimental data over the entire range of pressures. The representation and fitting of the models are important to estimate the energy in the form of the isosteric heats of adsorption (Qst), which were found to be 45 and 30 kJ·Kmol−1 for propyne and propylene, respectively. A Higher Qst value reveals strong interactions between the solid and the gas. The dynamic breakthrough for binary mixtures of C3H4/C3H6 (30:70 v/v)) were established. Heavier propylene molecules were eluted first from the column compared to the lighter propyne. Vacuum swing adsorption was best suited for the application of strongly bound materials in adsorbents. A six-step cycle was used for the recovery of high purity C3H4 and C3H6. The VSA system was tested with respect to changing blowdown time and purge time as well as energy requirements. It was found that the increase in purge time had an appositive effect on C3H6 recovery but reduced productivity and recovery. Accordingly, under the experimental conditions used in this study for VSA, the purge time of 600 s was considered a suitable trade-off time for purging. Recovery up to 99%, purity of 98.5% were achieved at a purge time of 600 s. Maximum achieved purity and recovery were 97.4% and 98.5% at 100 s blowdown time. Energy and power consumption varied between 63–70 kWh/ton at the range of purge and blowdown time used. The VSA offers a trade-off and cost-effective technology for the recovery and separation of olefins and paraffin at low pressure and high purity.


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