Plywood Made from Plasma-Treated Veneers: Investigation of Performance Differences between Plasma-Pretreated and Untreated Beech Veneers at Comparable Melamine Resin Load

In this study, the dimensional stability and mechanical properties of plywood made from untreated and plasma-pretreated beech veneers were compared. The wood veneers used (native and thermally modified) were impregnated with melamine resin in a simple dipping process prior to plywood production. The duration of the impregnation process was adjusted to give the same melamine resin loading for the different veneer types, with the plasma-pretreated veneers requiring only a fraction of the impregnation time compared with non-plasma-pretreated veneers. With comparable melamine loading, testing of the mechanical properties of the plywood for the different specimen collectives showed significant differences in some cases with respect to compressive strength, bending strength and tensile strength (with the associated moduli of elasticity). For example, it was shown that plywood made from plasma-pretreated native beech veneers shows an increase in bending strength of about 8%, and from plasma-pretreated and thermally modified beech veneers, there is an increase of about 10% compared to the reference.

Investigation into Biomass Tar-Based Carbon Deposits as Reduction Agents on Iron Ore Using the Tar Impregnation Method

Increasing carbon deposits in iron ore to upgrade the reduction rate can be performed by impregnating iron ore in tar. Carbon containing iron ore was prepared from low-grade iron ore and biomass tar, which was generated from palm kernel shell (PKS) pyrolysis using the impregnation method. The optimum condition of the method was investigated by varying the tar-iron ore ratio (1 and 1.5) and impregnation time (0 and 24 h). After the carbonization of the tar–iron ore mixture in a flow-type quartz tubular fixed-bed reactor at 500 °C for an hour, the carbon deposits adhered well to surfaces of all iron ore samples. The carbon deposits increased when the ratio of tar-iron ore was enhanced. The effect of impregnation time on the formed carbon deposit only applied to the tar-iron ore ratio of 1, but it had a weak effect on the ratio of 1.5. The highest carbon content was obtained from the impregnation of a biomass tar–iron ore mixture with the ratio of 1.5 which was directly carbonized. In addition, the high water content of biomass tar affected the reformation of FeOOH at the impregnation within 24 h. Furthermore, the reduction reactivity of the obtained carbonized ore, which was observed using thermogravimetric analysis, was perceptible. The carbon deposits on iron ore were able to demote total weight loss up to 23%, compared to 8% of the dehydrated ore, during the heating process to 950 °C. The carbon content obtained from iron ore impregnation with biomass tar can act as reduction agents, thereby enhancing the reduction reactivity.

Optimization Strategies for Improved Performance of Nano-Hybrid Wood/Polymer Composites Through Response Surface Methodology

Response surface methodology (RSM) was used to optimize the preparation conditions of nano-hybrid wood/polymer composites with montmorillonite (MMT) and furfuryl alcohol (FA). The effects of MMT amount, impregnation pressure and impregnation time on weigh percent gain (WPG) of treated samples were evaluated with Box-Behnken design (BBD) of a 3-level-3-factor from RSM. The predictive model for the response was extremely significant (p < 0.01). The determination coefficient (√R2) and the adjusted determination coefficient (VR2) of this model were 0.9651 and 0.9203, respectively. The optimal preparation conditions obtained by RSM design with the assistance of Design Expert were determined as follows: 4 wt% MMT amount, 0.8 MPa impregnation pressure, and 80 min impregnation time. It could be concluded from the SEM images that MMT and FA coated the cell walls and filled cell lumens. Moreover, the thermal stability was also investigated. The effects of preparation conditions were further validated by analyzing the water uptake ratio (WU), modulus of elasticity (MOE) and modulus of rupture (MOR) of the pristine samples and the treated samples prepared under optimized conditions.

EFFECT OF CO2-ADDED STEAM EXPLOSION ON OIL PALM EMPTY FRUIT BUNCH FOR BIOETHANOL PRODUCTION

This study aimed to investigate the effect of adding CO2 as an impregnation agent in steam explosion on oil palm empty fruit bunch (EFB) for bioethanol production. The influence of this treatment on the characteristics of EFB, enzymatic hydrolysis, and fermentation of EFB was evaluated in this investigation. CO2-added steam explosion was conducted varying the CO2 impregnation time (0, 30, 60 min). The results showed that the addition of CO2 in steam explosion increased the surface area, pore area, and pore volume of EFB. Furthermore, this treatment enabled obtaining yields of glucose and ethanol of 84.14% and 56.01%, respectively, for 60 min CO2 impregnation time. These results were higher than the glucose and ethanol yields of the sample treated by conventional steam explosion, which reached 58.12% and 41.37%, respectively. The findings illustrate the possibility of applying CO2-added steam explosion (CO2SE) for increasing the efficiency of biomass conversion.

Effect of Interpenetrating Polymer Network (IPN) Thermoplastic Resin on Flexural Strength of Fibre-Reinforced Composite and the Penetration of Bonding Resin into Semi-IPN FRC Post

The purpose of this study was to evaluate the effects of interpenetrating polymer network (IPN) thermoplastic resin on the flexural strength of fibre-reinforced composite (FRC) with different IPN polymer compositions. The penetration of bonding resin into semi-IPN FRC posts was also evaluated. The IPN thermoplastic resin used was UDMA-MMA monomer with either PMMA (0.5%, 2%, 5%) or PMMA-copolymer (0.5%, 2%). A no added IPN polymer resin was also made. Mixed resin was impregnated to S- and E-glass fibre rovings. These resins and resin impregnated fibres were used for flexural strength (FS) test. To evaluate the penetration of bonding resin into semi-IPN post, SEM observation was done with various impregnation time and polymerization mehods (hand-light- and oven-cure). The result of FS was recorded from 111.7 MPa (no-IPN polymer/no-fibre-reinforcement) to 543.0 MPa (5% PMMA/S-glass FRC). ANOVA showed that there were significant differences between fibre-reinforcement and no-fibre-reinforcement (p < 0.01) both in S- and E-glass fibre groups, and between 0.5% PMMA and 5% PMMA in the S-glass FRC group. SEM micrographs showed that the penetration layers of bonding resin into hand-light cured semi-IPN posts were different according to impregnation time. Fibre reinforcement is effective to improve flexural strength. The depth of penetration layer of bonding resin into semi-IPN matrix resin was improved when a hand-light cure was used.

The Effect of Alcohol on Palladium Nanoparticles in i-Pd(OAc)2(TPPTS)2 for Aerobic Oxidation of Benzyl Alcohol

In the heterogeneous catalyst i-Pd(OAc)2(TPPTS)2, Pd(II) was reduced to Pd(0) by using different alcohol solvents, and the catalyst’s activity was studied in the aerobic oxidation of benzyl alcohol. We studied the effects of the impregnation time in ethanol as a solvent and the use of various alcoholic solvents on the size of palladium nanoparticles. We found that the reduction of palladium by the various alcohols yielded palladium nanoparticles that were active in the aerobic oxidation of benzyl alcohol. As determined by DLS, TEM, and zeta potential analyses, both the impregnation time in ethanol and the type of alcohol used were observed to affect nanoparticle formation, particle size distribution, and agglomeration, as well as the conversion rate. The palladium nanoparticles’ hydrodynamic diameter sizes obtained during the 24 h of impregnation time were in the range of 10–200 nm. However, following 24 h of impregnation in ethanol the nanoparticles tended to form aggregates. The conversion rates of all the primary alcohols were similar, while for secondary alcohol, in which the hydrogen of the hydroxyl is less acidic and there is steric hindrance, the conversion was the lowest. Performing the oxidation using the solvent 1-propanol yielded smaller nanoparticles with narrower distributions in comparison to the reaction that was observed when using the ethanol solvent. On the other hand, the relatively high particle size distribution in 1-hexanol yielded agglomerates.

Supercritical CO2 Assisted Impregnation of Ibuprofen on Medium-Chain-Length Polyhydroxyalkanoates (mcl-PHA)

In this work, we propose the utilization of scCO2 to impregnate ibuprofen into the mcl-PHA matrix produced by Pseudomonas chlororaphis subs. aurantiaca (DSM 19603). The biopolymer has adhesive properties, is biocompatible and has a melting temperature of 45 °C. Several conditions, namely, pressure (15 and 20 MPa) and impregnation time (30 min, 1 h and 3 h) were tested. The highest ibuprofen content (90.8 ± 6.5 mg of ibuprofen/gPHA) was obtained at 20 MPa and 40 °C, for 1 h, with an impregnation rate of 89 mg/(g·h). The processed mcl-PHA samples suffered a plasticization, as shown by the decrease of 6.5 °C in the Tg, at 20 MPa. The polymer’s crystallinity was also affected concomitantly with the matrices’ ibuprofen content. For all the impregnation conditions tested the release of ibuprofen from the biopolymer followed a type II release profile. This study has demonstrated that the mcl-PHA produced by P. chlororaphis has a great potential for the development of novel topical drug delivery systems.

Preparation and Characterization of Bio-Nitrogen-Doped Activated Carbon

Blood (livestock blood) is a cheap and readily available biomass material with a relatively high protein content.In this study, bio-nitrogen doped activated carbon (BN-AC) was prepared by chemical activation method with nitrogen-rich pig blood as raw material and magnesium chloride as activator.The specific surface area of BN-AC is 283.719 m2/g, and the pore volume is 0.128 cm3/g.The optimum conditions for the preparation of BN-AC were as follows: the mass impregnation ratio of activator to blood powder was 2:1, the impregnation time was 12 h, and the activation temperature was 600 ℃.The forms of biological nitrogen in activated carbon were studied by elemental analysis, Boehm titration, FTIR and XPS.The results showed that the total basicity of 0.720 mmol/g, and acidity of 0.313 mmol/g of the BN-AC.The surface of the precursor has only one Pyrrolic N, and the surface of BN-AC contains Pyridinic N, Pyrrolic N and Graphitic N, the N content of the precursor was successfully preserved.BN-AC has higher methylene blue and iodine adsorption values than ordinary activated carbon.

A Review on Preparation and Characterization of Activated Bio-Char

Activated charcoal (AC) is a carbonaceous material with high surface area due to high degree of micro-porosity which makes it a very versatile adsorbent for utilization in industrial, medicinal, environmental and other fields. Ligno-cellulosic biomass (eg. pine needles, paddy stubbles, other waste agricultural residue) can be a prominent raw material for activated bio-char due to its abundance, slow decomposition (which lead to fire/ air pollution). The main factors which affect the AC characteristics (surface area, micropore volume, mesopore volume) are biomass properties, impregnation ratio, impregnation time, activation temperature and activation time. The specific surface area, micropore, mesopore decreases after optimum value with continually increase in impregnation ratio and impregnation time. The activation temperature and impregnation ratio also affect the AC yield significantly. Sorption capacity get affected by adsorbent doses, contact time, agitation speed, adsorption temperature due to availability of active binding sites, adsorptive forces/ bonds.

Design of locally sourced activated charcoal filter from maize cob for wastewater decontamination: an approach to fight waste with waste

This research studied decontamination of laboratory wastewater with an activated carbon derived from maize cob, an agricultural waste to ascertaining its adsorption effectiveness for water treatment. The preparation conditions such as the concentration of the activating agent, impregnation ratio, impregnation temperature, impregnation time, activation temperature and activation time were optimized. The adsorbent’s porous properties revealed its adsorption potency was correlated with the iodine value. The test adsorbent showed significant contaminants adsorption in the laboratory wastewater; the results obtained were within the standards for drinking water set by the regulatory agencies. This agricultural waste could be considered for the preparation of activated carbon which would ultimately serve as an alternative method of decontaminating laboratory wastewater.