Wood Water Research Articles

Super-hydrophilic carbonized wood-based solar steam evaporator: A novel approach to enhance freshwater generation

Solar steam evaporation has been shown to represent an advanced approach to freshwater generation. The primary obstacles in developing solar steam generation devices utilizing biomass materials include intricate manufacturing procedures and a comparatively lower energy conversion efficiency. Here, we detailed a straightforward approach involving the deposition of polydopamine (PDA) onto carbonized wood, creating an innovative solar interface evaporation device. Treated wood obtained by removing a part of lignin and hemicellulose was transformed into carbonized wood through a straightforward wood carbonization process. Subsequently, the carbonized wood's water and light absorption were further enhanced by applying a hydrophilic coating using dopamine (DA) and diethylenetriamine (DETA). The result was the development of a wood-based solar interface evaporator capable of performing three essential functions: light absorption, photothermal conversion, and water transfer. The Super-hydrophilic carbonized wood (SCW) solar steam evaporator possessed an evaporation efficiency of approximately 91.81 %, net evaporation of 1.7853 kg m−2 h−1 in seawater, an evaporation efficiency of approximately 78.44 %, and net evaporation of 1.52538 kg m−2 h−1 in groundwater at one sun, respectively. Therefore, SCW holds substantial promise for applications in seawater desalination and groundwater extraction, offering a valuable solution to address the issue of inadequate freshwater availability.

Water soaking and benzyladenine treatment for higher grafting success in grapevine

The grafting of grapevines has become essential to overcome biotic and abiotic stresses. Also, stimulating the grafting union's rapid formation is the key to grafting success. This investigation was an attempt to study the effect of removing growth inhibitors through soaking of scion wood in water for 24 hours versus adding growth stimulation through fast dipping in 250 ppm benzyl adenine (BA) for 30 seconds before grafting, on the grafting success of Flame Seedless and Early Sweet scions (Vitis vinifera) grafted onto Freedom rootstock (Vitis champinii x 1613C) in addition to the control treatment. Water soaking was the best and followed by the treatment of 250 ppm BA, which significantly improved the grafting success of both cultivars. Grafting success was positively associated with increasing callus formation at the grafting zone, accompanied by the highest total indols content, the lowest total phenols content and peroxidase activity above and below the grafting zone. However, water soaking significantly increased total indols and decreased total phenols content of the ungrafted cuttings. This study suggests that applying water soaking to grape scion before grafting is an environmentally friendly, sustainable and alternative practice for synthetic growth regulators to improve grafted cuttings success.

The study of colour changes under artificial weathering of light red meranti and yellow balau wood from Shorea genus

The study of colour changes under artificial weathering of light red meranti and yellow balau wood from Shorea genus. This paper deals with the change in colour of selected tropical wood species from Shorea genus such as light red meranti and yellow balau. The artificial weathering method was used to determine the colour stability of wood surface. The used ageing method consisted of alternating soaking wood in water, drying at a temperature of 70°C and UV irradiation exposure. The colour changes were evaluated using CIE L*C*h system. Changes of particular colour parameters (lightness L*, chroma C*, hue h) were determine as well as the total colour change ΔE*. The results showed that tested species of wood change their colour similarly under the influence of the artificial weathering (the changes in the tested wood appearance occurred in similar scope). Surfaces of tested wood species initially became darker and then lighter. The largest changes in intensity of the colour of wood took place at the beginning of artificial weathering process. The intensity of changes decreased with the progress of aging process.

Wood decomposition in aquatic and terrestrial ecosystems in the tropics: contrasting biotic and abiotic processes.

Wood decomposition, a critical process in carbon and nutrient cycles, is influenced by environmental conditions, decomposer communities and substrate composition. While these factors differ between land and stream habitats, across-habitat comparisons of wood decay processes are rare, limiting our ability to evaluate the context- dependency of the drivers of decay. Here we tracked wood decomposition of three tree species placed in stream and terrestrial habitats in a lowland tropical forest in Panama. At 3 and 11 months we measured mass loss, wood nitrogen and wood polymer concentrations, and sampled wood-associated fungal and bacterial communities. After 11 months of decay we found that mass loss occurred 9% faster in streams than on land, but loss of cellulose, hemicellulose and lignin did not differ between habitats. We also observed large differences in microbial decomposer communities between habitats. Overall, we found faster mass loss of wood in water, but no differences in biotic decay processes between habitats despite distinct microbial communities in streams and on land. Our research challenges the assumption that wood decays relatively slowly in water reflecting unfavorable environmental conditions and a limited capacity of aquatic microbial communities to effectively degrade wood polymers.

Chemical characterization of Cedrus deodara wood extracts using water and molybdenum catalysts

The effect of the presence of some molybdenum catalysts on the amount of extractives in cedar wood has been studied. Autoclave treatment of cedar wood in the presence of some molybdenum catalysts can increase the amount of extracts. While autoclave treatment of cedar wood in water gave 2.85% extractives, the same treatment in the presence of H3PMo12O40 gave 7.51% extractives. In the presence of silica-supported MoO3, the amount of extractives was 5.50%. The extractives obtained using water were partially soluble in chloroform (40.7%). Only 27.6% of the extractives obtained using H3PMo12O40 was soluble in the same organic solvent. When cedar was treated with silica-supported MoO3, 56.4% of the extractives was soluble in chloroform. The extracts can be a source of fatty acids for biodiesel production and simple carbohydrates. The analysis of the chloroform-soluble fraction showed that the autoclave treatment of cedar wood gave 49.7% of a mixture of 2-hydroxy-1-(hydroxymethyl)ethyl hexadecanoate, 2-hydroxy-1-(hydroxymethyl)ethyl octadecanoate, and 2,3-dihydroxypropyl octadecanoate. The extractives obtained in the presence of the polyoxometalate molybdenum derivative gave 95% of the same esters of fatty acids, while those obtained in the presence of silica supported MoO3 showed the presence of 93% of the same esters. Gas chromatography–mass spectrometry (GC-MS) of water-soluble fraction showed the presence of some simple carbohydrates, mainly ribose, xylose, and arabinose.

Physicochemical perspective on “polydopamine” and “poly(catecholamine)” films for their applications in biomaterial coatings (Review)

Bioinspired poly(catecholamine) based coatings, mostly "polydopamine," were conceived based on the chemistry used by mussels to adhere strongly to the surface of stones and wood in water and to remain attached to their substrates even under conditions of strong shear stresses. These kinds of films can in turn be easily modified with a plethora of molecules and inorganic (nano)materials. This review shows that poly(catecholamine) based coatings are an ideal film forming method for applications in the field of biomaterials. It is written from a physicochemical and a materials science perspective and discusses optical, chemical, electrochemical, and mechanical properties of polydopamine films. It further demonstrates that a better understanding of the polydopamine film deposition mechanism is warranted to improve the properties of these coatings even further.

목재사방댐에 사용된 낙엽송 부재의 내구성 평가

본 연구는 목재사방댐에 사용된 국산 낙엽송재의 내구성을 평가하기 위하여 수행되었다. 낙엽송부재의 수중침적부위, 미침적부위 및 대기중 방치재를 공시재료로 이용하였다. 낙엽송 부재의 설치 위치 및 설치 후 기간 경과에 따른 목재조직의 열화정도는 광학현미경 및 주사전자현미경으로 관찰하였고, 각 조건 및 부위별 시료의 종압축강도와 전단강도는 만능강도측정기로 측정하였다. 그 결과, 수중 침적부위는 사용기간이 7년 이상 경과해도거의 정상재와 유사한 해부 및 역학적 특성을 나타냈다. 수중에 침적되지 않은 부재의 경우, 심재는 기간이 경과해도 정상재와 유사한 양호한 상태를 유지하고 있었으나, 변재는 5년 이상 경과됨에 따라 세포벽이 얇아지거나 붕괴되는 열화가 발생하였다. 또한 변재는 사용기간이 경과함에 따라 역학적 특성이 크게 저하되었으나, 심재는 비교적 그 저하율이 작았다. 사방댐 제작 후, 자연상태에서 그대로 방치된 잔여 목재는 열화의 정도가 심하고 강도적 성능이 크게 저하되어 사방용 부재로의 역할을 수행하기에는 부적합한 것으로 나타났다. This research has been carried out to evaluate the durability characterization of larch wood used for woody erosion control dam. Wood deterioration and strength properties were analyzed according to installed position and duration. Optical and scanning electron microscope were used for examining wood deterioration, and an universal testing machine was applied for compression and shearing strength. As a result, deposited wood in water was maintained almost similar anatomical and physical properties compare to normal wood, even though it was used for seven years. In non-deposited wood which was installed on the side of the dam, heartwood did not show any significant change during seven years, while sapwood was significantly deteriorated in five years. Also, strength properties of sapwood were significantly decreased according to installed duration whereas, degree of decrease in heartwood were relatively smaller than that in sapwood.

Influência da Época de Colheita e da Estocagem na Composição Química da Biomassa Florestal

This study determined the chemical composition variation of forest biomass according to harvest season and storage time. The experiment was carried out in Lages, State of Santa Catarina. Logs with bark of Pinus taeda L. and Eucalyptus dunnii Maiden were collected after harvest with two, four and six months of storage time. Solubility of wood in water, sodium hydroxide, toluene and alcohol and ash contents were evaluated. The chemical composition of wood with bark varied according to the harvest season of the trees. The highest values of extractives and ash content were obtained in summer and spring. The storage time caused variations in the chemical composition of forest biomass. Changes caused by the oxidation and transformation of extractives have occurred, resulting in increased solubility in water and alcohol toluene. Variations in the chemical composition alone did not contribute to the improvement of the biomass energetic quality.

Modelling inorganic biocide emission from treated wood in water

The objective of this work is to develop a chemical model for explaining the leaching behaviour of inorganic biocides from treated wood. The standard leaching test XP CEN/TS14429 was applied to a commercial construction material made of treated Pinus sylvestris (Copper Boron Azole preservative). The experimental results were used for developing a chemical model under PHREEQC ® (a geochemical software, with LLNL, MINTEQ data bases) by considering the released species detected in the eluates: main biocides Cu and B, other trace biocides (Cr and Zn), other elements like Ca, K, Cl, SO 4 −2, dissolved organic matter (DOC). The model is based on chemical phenomena at liquid/solid interfaces (complexation, ion exchange and hydrolysis) and is satisfactory for the leaching behaviour representation. The simulation results confronted with the experiments confirmed the hypotheses of: (1) biocide fixation by surface complexation reactions with wood specific sites (carboxyl and phenol for Cu, Zn, Cr(III), aliphatic hydroxyl for B, ion exchange to a lesser extent) and (2) biocide mobilisation by extractives (DOC) coming from the wood. The maximum of Cu, Cr(III) and Zn fixation occurred at neutral pH (including the natural pH of wood), while B fixation was favoured at alkaline pH.

Mechanism of partial fixation of compressed wood based on a matrix non-softening method

Three different mechanisms to explain the partial fixation of the compressive deformation of wood are postulated: non-softening, cross-linking and stress relaxation. This study attempted to fix the compressive deformation of wood by the non-softening mechanism of the cell-wall matrix using acetylation of the cell wall making it more hydrophobic. In this method, partial recovery of compressive deformation by wetting decreased at room temperature as the acetyl content increased. However, almost complete recovery occurred by boiling the compressed wood in water or soaking in acetone. This is due to the ability of boiling water or acetone to soften the cell-wall matrix of acetylated wood enough to enable recovery from compression. It is, therefore, possible to partially fix the compressive deformation of wood, preventing the resoftening of the cell-wall matrix in water.

Catalytic influence of wood on the hardening behavior of formaldehyde-based resin adhesives used for wood-based panels

The aim of this work was to monitor the hardening behavior of two different ureaformaldehyde (UF) resins and to investigate the possible catalytic effect of cold water extractives of different wood species on the hardening characteristic. A pure UF resin and a melamine-modified UF resin were used for this investigation. For the experiments, ammonium chloride, ammonium sulphate, acetic acid and oxalic acid at different addition levels were used as hardeners. The gel times determined at three temperatures, the pH drop of the resins after the hardener addition, the buffering behavior and changes in the complex viscosity η * with time, as well as the development of the bond strength were chosen as parameters for characterizing the systems both with and without wood extractives. As expected, the buffering capacity of the melamine fortified resin was found to be much greater than for the pure UF resin. The gel times of the investigated resins were strongly dependent on the applied temperature, decreasing steeply at higher temperatures. Based on these data the apparent activation energies for various hardener additions have been calculated. The complex viscosity and the development of the internal bond strength indicated that cold water wood extractives had little or no effect on the curing progress of the resins.

Amount of leachant and water absorption levels of wood treated with borates and water repellents

Wood protection efficacy of borates against biological agents, flame retardancy, and suitability to the environment is well known. Since borates can be applied to timber as water based solutions, they are preferred economically as well. Even though they are highly mobile in wood, boron compounds are widely used in timber preservation. Borates migrate in liquid and increase the hygroscopicity of wood in damp conditions. This study deals with the physical restriction of water access in wood by impregnating water repellent agents into wood to limit amount of leachant and water absorption levels of wood after boron treatment. Borates were incorporated with polyethylene glycol-400 (PEG-400) their bulking effect in wood was considered. Results indicated that the amount of leachates from wood treated with borates in PEG-400 was remarkably higher compared to those of wood treated with the aqueous solutions of borates. Water absorption (WA) levels of wood treated with aqueous solutions of borates were higher than those of their treated samples with the solutions in PEG-400. Secondary treatments of wood with the water repellent (WR) chemicals following borate impregnation reduced the leaching of chemicals from wood in water and also WA of the specimens were less than those of the wood treated with only borates from aqueous and PEG solutions. Styrene (St) was the most effective monomer among the other agents used in terms of immobility effect on borates and WA.

Estimation of Fibre Saturation Point from Sorption Behaviour of Wood In Water

The fibre saturation point of wood is of tremendous importance both to the processing and properties of the material and as a result research on the various possible ways of estimating it can hardl ...

Swelling of acetylated wood in organic solvents

To investigate the affinity of acetylated wood for organic liquids, Yezo spruce wood specimens were acetylated with acetic anhydride, and their swelling in various liquids were compared to those of untreated specimens. The acetylated wood was rapidly and remarkably swollen in aprotic organic liquids such as benzene and toluene in which the untreated wood was swollen only slightly and/or very slowly. On the other hand, the swelling of wood in water, ethylene glycol and alcohols remained unchanged or decreased by the acetylation. Consequently the maximum volume of wood swollen in organic liquids was always larger than that in water. The effect of acetylation on the maximum swollen volume of wood was greater in liquids having smaller solubility parameters. The easier penetration of aprotic organic liquids into the acetylated wood was considered to be due to the scission of hydrogen bonds among the amorphous wood constituents by the substitution of hydroxyl groups with hydrophobic acetyl groups.

Swelling of acetylated wood I. Swelling in organic liquids

To investigate the affinity of acetylated wood for organic liquids, acetylated yezo spruce wood specimens were soaked in various liquids, and their swellings were compared to those of untreated specimens. The acetylated wood was rapidly and remarkably swollen in liquids having low hydrogen bonding power such as benzene and toluene in which the untreated wood was swollen only slightly or very slowly. On the other hand, the swollen volume of wood in water, ethylene glycol, and alcohols remained unchanged or slightly decreased after the acetylation. The effect of acetylation was greater in liquids having smaller solubility parameters. The easier penetration of aprotic organic liquids into the acetylated wood was considered to be due to the reduction of polarity and the scission of hydrogen bonds in the amorphous wood constituents where the hydrophilic hydroxyl groups were substituted by hydrophobic acetyl groups.

Resistance to electrochemical corrosion of CrxNy- and DLC-coated steel tools in the environment of wet wood

We have shown in an earlier work that in wood machining the degree of blunting of steel knives due to electrochemical corrosion is small as compared to their abrasive wear. However, the corrosion of steel knives may occur during the cut-offs of the machining operation, when the knife does not work but is still covered with the extract of wood in water. The anti-abrasive coatings deposited on steel knives may also protect them against corrosion. The aim of the present study was to examine how coatings with good anti-abrasive properties (CrxNy and DLC) can protect low-Cr steel against electrochemical corrosion. The corrosion of the coated steels did not depend noticeably on the kind of wood, despite the difference in the pH value of their water suspensions. All the coatings appeared to improve the corrosion resistance of the steel. The best results were achieved with the DLC coating deposited by cathodic arc evaporation and CrN+Cr2N coating deposited by magnetron sputtering, although steel covered with these layers has shown pitting corrosion.

Prehydrolysis Sulfite Revisited

AbstractThe prehydrolysis of beech wood in water at different temperatures and the impact of this treatment on further pulping stages were explored. Both, increased condensation degree and an increased number of free phenolic hydroxyl groups were found in the lignin isolated after prehydrolysis. An intermediate alkaline extraction (using either NaOH or MgO as base) following the prehydrolysis was explored. Finally, acid sulfite cooks of the differently pre‐treated materials were performed, and the obtained materials thoroughly analyzed.

Dielectric Relaxation Based on Adsorbed Water in Wood Cell Wall under Non-Equilibrium State. 1

Summary In order to make clear the molecular mechanism of the dielectric relaxation based on adsorbed water in wood cell wall during moisture changing process, the temperature and frequency spectrums of dielectric processes of Sikkim spruce (Picea spinulosa Griff.) were measured in three different adsorption processes. Three levels of relative humidity used were 40, 80 and 100 %, respectively, and the temperature was kept at 20°C. In oven-dry state, relaxation process I based on the reorientation of CH2OH groups in amorphous region of wood cell wall was observed. While in moist state, relaxation process II based on ionic conductivity and relaxation process III based on the additive reorientation of CH2OH groups and adsorbed water molecules occurred. Within higher humidity region, relaxation process IV concerned with adsorbed water in lignin was observed in the initial adsorption period, but it vanished with further adsorption.

Swelling of wood

The rate and maximum swelling of several North American wood species in water have been obtained with a computer interfaced linear variable displacement transformer. Since wood swells extremely fast in water even at room temperature, this apparatus made it possible for the first time, to obtain accurate rate data on the swelling of wood in water. The strict linear dependence of swelling on the temperature suggests a chemical mechanism. The activation energies obtained from Arrhenius plots ranged from 32.2 KJ/mole for sitka spruce to 47.6 KJ/mole for sugar maple. Although the two hardwoods exhibited greater maximum tangential swelling compared with the two softwoods, the maximum swelling appears to be correlated with the wood density. Generally both the rate and maximum swelling of the woods were increased by removal of extractives and the activation energies were reduced.

Effect of hydro-thermal treatment of green beech wood on its chemical and physco-mechanical properties

Preliminary investigations were carried out aiming at the establishment of relationships between chemical, physical, and mechanical properties of beech wood under the influence of heating in water at 50°C and 100°C at pH values from 2.8 to 8.5 and with heating times up to 25 hours. It was found that heating of beech wood in water at 50°C does not produce remarkable changes in its properties. When green wood was heated at 100°C, insignificant changes in its density, shrinking, and α-cellulose content were observed, whereas a considerable decrease in strength was found when tested in a wet state. It was further observed that on prolonged heating, the reactions of the wood and the solutions used as a heating medium under-went distinct changes, attaining an equivalent value approximating the final pH of the wood.