Research Article

Uses of Nanostructures in Innovative Composite Wood Products and Their Applications

Abdur Rahman Khan1*, Mansoor Ali Khan1, Abdur Rehman1 and Muhammad Umair Khan1

Pakistan Forest Institute, Peshawar, Khyber Pakhtunkhwa, Pakistan.

Received | April 27, 2023; Accepted | May 13, 2023; Published | June 26, 2023

*Correspondence | Abdur Rahman Khan, Pakistan Forest Institute, Peshawar, Khyber Pakhtunkhwa, Pakistan; Email: [email protected]

Citation | Khan, A.R., Khan, M.A., Rehman, A. and Khan, M.U., 2023. Uses of nanostructures in innovative composite wood products and their applications. Pakistan Journal of Forestry, 73(1): 24-34.

DOI | https://dx.doi.org/10.17582/journal.PJF/2024/73.1.24.34

Keywords | Nanostructures, Composite wood products, Application, Wood based panels

Copyright: 2023 by the authors. Licensee ResearchersLinks Ltd, England, UK.

This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).

Introduction

Nanotechnology is a science in which matter are manipulated to a size of 1-100 nm. In this we incorporate science and technology with each other having diverse applications with the aims to develop and improve the various physical and mechanical properties (Wegner and Jones, 2006, 2009). Nano leveled materials exhibit distinguished and unique properties than that of original (Bajpai, 2016). Nanotechnology is a versatile field which has multipronged uses in the medical bio sensing and catalytic activates etc. (Lohcharoenkal et al., 2021). Twenty first century is considered as the new era of nanotechnology for uplifting the bio economy of the country by the development of various nano based products (Rani et al., 2020; Singh et al., 2018, 2019). As it is evident that nanotechnology uses are multifarious, but in the present era its use has been focused in wood-based industries. The non-nano based wood products are generally less durable, unstable, carcinogenic, and less eco-friendly. The nanomaterial’s make wood products more resistant to pests, decrease the surface hydrophylicity, fire resistant, durable, and UV absorption (Bueno et al., 2014; Cristea et al., 2011; De Filpo et al., 2013). These nanostructures also increase the preservation and decreasing the leaching of wood by limiting the penetration of agents to wood (Liu et al., 2002; Peteu et al., 2010; Salma et al., 2010). Nanoparticles are added to the wood based products by following methods like, direct addition to the adhesive or by post treatment of finished products by applying nano based coating (Pizzi and Mittal, 2017; Carvalho et al., 2012; Kim, 2009; Myers, 1989; Conner and Madariaga, 1996). The doped nanoparticles shows greater activity than its pure form like, samarium doped cerium oxide 10-20% greater than common ceria (Balamurugan et al., 2020). Nanostructures also indirectly put a good impact on climate by avoiding carbon emission to atmosphere through preserving wood decay. It is expected that steel, concrete and aluminum have high carbon footprint than that of wood and the CO2 emission can be reduced by 14% using wood-based products in buildings (Global Status Report: Towards a Zero-Emission, Efficient and Resilient Buildings and Construction Sector, 2018). Hence the vast uses of nanoparticles in different fields it will increase the life span and durability of composite wood products.

Nanostructures used in composite/wood based products

So far different nanostructure either in pure or in doped form have been used in wood based products for better and efficient results like to increase durability, high physic-mechanical properties, fire resistance and hydrophobicity etc. The following are the important nanomaterials used in composite wood products.

Graphene oxide nanopatrticle

Graphene are mono layered carbon atoms with hexagonal structure having Sp2 hybridization (Jagiełło et al., 2020). Mostly Hummer method is used for the preparation of graphene nanoparticles (Hummers and Offeman, 1958). Graphene nanoparticle improved the physical properties like water absorption, thermal conductivity and thickness swelling up to 19.5%, 39.79% and 50%, respectively. Similarly, the graphene oxide also improved the mechanical properties like modulus of elasticity (MOE), modulus of rupture (MOR) and internal bond up to 19.22%, 38.8% and 28.5%, respectively (Gul and Alrobei, 2021). The Table 1 show the properties of wood products when graphene oxide was incorporated as nanoparticle.

Iron oxide (Fe2O3 and Fe3O4) nanoparticles

In nature Iron exist in many forms but the two important ones are Fe2O3 and Fe3O4 (Cornell and Schwertmann, 2003). As compared to bulk form the nanostructure of iron oxide possesses unique magnetic, optical and electrical properties (Iriarte-Mesa et al., 2020). Pyrolysis method is used specially for the preparation of iron oxide nanostructure (Jia et al., 2011). By adding 1%Fe3O4 to the MDF increased 8.5% internal bonding (IB). Moreover, the shielding effect was increased significantly by adding 10% of Fe3O4 to MDF (Pourjafar et al., 2022). The Table 2 show the properties of wood products when Iron oxide was incorporated as nanoparticle.

Titanium oxide (TiO2) nanostructure

Titanium oxide (TiO2) nanomaterial’s is prepared particularly by hydrothermal process (Meng et al., 2016). The various functionality in wood is enhanced by TiO2 nanoparticle like fire resistance (Sun et al., 2010), prevent weathering (Mahltig et al., 2008; Rassam et al., 2012; Schmalzl and Evans, 2003), dimensional stability (Sun et al., 2010), and rot protection (Mahr et al., 2013). Apart from wood or wood based products TiO2 nanostructure is also used for bio sensing purpose through caped ionic liquids. The Table 3 show the properties of wood products when Titanium oxide was incorporated as nanoparticle.

 

Table 1: Effect of Graphene oxide (GO) and reduced graphene oxide (rGO) on properties of MDF (medium density fiber board).

Wood products	Type of nanoparticle	Properties	Effect (increase/decrease)	Reference
MDF (Medium density fiber board)	Graphene oxide (GO) and reduced graphene oxide (rGO)	Thickness swelling, water absorption, thermal conductivity, internal bond and rupture modulus	Significantly improved	(Gul et al., 2023)

 

Table 2: Effect of iron oxide (Fe2 O3 ) on properties of MDF (medium density fiber.

Wood products	Type of nanoparticle	Properties	Effect (increase/ decrease)	Reference
MDF (Medium density fiber board)	iron oxide (Fe2O3)	Thickness swelling, water absorption, moisture content and density	Significantly improved	(Pourjafar et al., 2023)

 

Silica (SiO2) nanostructure

Nano silica has novel and unique properties, due to which it is incorporated to the woody or non woody based materials to increase strength, hardness durability, modulus and decrease the rate of degradation (Li et al., 2004; Guefrech et al., 2011; Tobón et al., 2012). The nanosilica is prepared from its basic rice husk source through many steps (Yalcin and Sevinc, 2001). The Table 4 show the properties of wood products when Silica was incorporated as nanoparticle.

Zinc oxide (ZnO) nanostructure

Zinc oxide nanostructure is prepared generally by thermal decomposition method (Salavati-Niasari et al., 2008). Urea formaldehyde is a gluing agent in composite wood products. When zinc oxide nanostructure is mixed with urea formaldehyde in the manufacturing of MDF (medium density fiber board) increases and improves the water absorption and thickness swelling (Gul et al., 2021). 1% addition of ZnO to the wood based products increases modulus of elasticity (MOE) and modulus of rupture (MOR) (Candan and Akbulut, 2015). The Table 5 show the properties of wood products when Zinc oxide was incorporated as nanoparticle.

Silver nanoparticles (AgNPs)

Among various metallic nanoparticles silver nanostructure is the most important and fascinating ones for biomedical application, industries, food and optical sensor etc. (Mukherjee et al., 2001; Chernousova and Epple, 2013). Generally, the silver nanostructure is prepared by various methods like physical, chemical and biological method. Pyrolysis and spark discharging are the two main conventional physical methods which are used for synthesis of silver nanomaterials (Tien et al., 2008; Pluym et al., 1993). While organic solvents or water is used in chemical method for the synthesis of silver nanostructures (Tao et al., 2006; Wiley et al., 2005). To reduce the limitation of chemical method the silver nanoparticles is prepared by green synthesis using fungi, bacteria and plant extract (Ganaie et al., 2015). Addition of silver nanomaterials to the MDF shows better hardness at 6minute hot pressing. When hot press time increase it decrease the hardness of MDF because of De-polymerization (Taghiyari and Norton, 2014). The Table 6 show the properties of wood products when Silver oxide was incorporated as nanoparticle.

 

Table 3: Nano fibrillated cellulose (NFC) and titanium dioxide (TiO2) effect on particle board properties.

Wood products	Type of nanoparticle	Properties	Effect (increase/decrease)	Reference
Particle Board	Nano fibrillated cellulose (NFC) and titanium dioxide (TiO2)	Thickness swelling, water absorption, moisture content, internal bond and rupture modulus	Significantly improved	(Ümit Yalçın, 2023)

 

Table 4: Silica nanostructures impact on physical properties Particle Board, MDF and Ply wood.

Wood products	Type of nanoparticle	Properties	Effect (increase/decrease)	Reference
Particle Board, MDF and Ply wood	SiO2	Thickness swelling, water absorption, and internal bond	Significantly improved only in case of MDF internal bond decrease	(Valle et al., 2020; Dukarska and Czarnecki, 2016; Khanjanzadeh et al., 2014)

 

Table 5: Effect of ZnO on MDF properties.

Wood products	Type of nanoparticle	Properties	Effect (increase/decrease)	Reference
MDF	ZnO	Thickness swelling and water absorption	Significantly improved	(Gul et al., 2021)

 

Table 6: Effect of silver oxide nanoparticle on MDF properties.

Wood products	Type of nanoparticle	Properties	Effect (increase/decrease)	Reference
MDF	AgO	Thickness swelling, hardness and water absorption	Significantly improved	(Taghiyari and Norton, 2014)

 

Table 7: Al2 O3 effects on properties of MDF.

Wood products	Type of nanoparticle	Properties	Effect (increase/decrease)	Reference
MDF	Al2O3	Thickness swelling, water absorption, internal bonding (IB), modulus of elasticity (MOE) and modulus of rupture (MOR),	Significantly improved	(Gul et al., 2020)

 

Table 8: Effects of Wollastonite on MDF properties.

Wood products	Type of nanoparticle	Properties	Effect (increase/decrease)	Reference
MDF	Wollastonite	Density and gas liquid chromatography	Significantly improved	Taghiyari and Samadi, 2016

 

Alumina (Al2O3) nanostructure

Alumina (Al2O3) is considered the most vital ceramic materials have magnificent characteristics like high strength gigantic electrical insulation, good catalytic activity, colossal hot-hardness, high thermal conductivity, fabulous dielectric properties, chemical inactiveness, huge melting temperature and good stiffness etc. (González et al., 2012; Song et al., 2005; Qu et al., 2005; Issa et al., 2018). Several methods are reported for alumina nanoparticle preparation like hydrothermal (Qu et al., 2005), sol-gel (Li et al., 2006) and precipitation method etc. (Song et al., 2005). By the addition of 4.5% alumina nanostructure to medium density fiberboard (MDF) increases and improves the modulus of elasticity (MoE), modulus of rupture (MoR) and internal bond (IB) to a level of 31%, 22.12% and 16.4%, respectively. By comparing to the controlled and normal MDF alumina nanostructure also increases water absorption and thickness swelling 37.53% and 40.15%, respectively (Alabduljabbar et al., 2020). The Table 7 show the properties of wood products when Alumina was incorporated as nanoparticle.

Wollastonite nanofibers 

Wollastonite chemically a calcium silicate minimizes the effects of various pathogens and flourishes the plant growth (Fernández-Puratich and Oliver-Villanueva, 2014). Due to the huge thermal conductivity of wollastonite (Taghiyari et al., 2013) its nanofibers significantly improves the solid wood dimensional stability (Poshtiri et al., 2014) and enhances the medium density fiberboard thermal conductivity coefficient (Taghiyari and Norton, 2014). Wollastonite nano fibers minimized the gas and liquid permeability to medium density fiberboard (MDF) significantly, So, its durability is increase (Taghiyari and Samadi, 2016). The Table 8 show the properties of wood products when Walsonite was incorporated as nanoparticle.

Application of nanotechnology

The nanomaterials have multidisciplinary uses including wood and wood composite materials (Wu et al., 2011). In order to increase and fascinate the quality of wood based composites nanotechnology is introduced which also fulfill the demands for new products in the modern era. Various components like, moisture contents, pathogens and structure instability causes various wood drawbacks in its utilization. These limitations are caused due to many hydroxyl group and polymer nature of cell wall (Papadopoulos, 2010). Naturally wood is a hygroscopic material and the absorption capability of wood to moisture contents is directly related to the surface area exposed.

Properties enhancement of wood based panels by nanomaterials

Wood composites are the combination of various wood elements combined by adhesives (Kevin et al., 2018). As compared to common wood the wood composite properties are generally regarded as stronger. Wood based products for specific purpose at various grade, size and thickness can be easily manufactured. The main limitations and disadvantages of the wood composite products are like that they require high primary energy for manufacturing prone to humidity and releases toxic formaldehyde as compared to the solid lumber. In order to overcome all the above mentioned limitations and disadvantages nanotechnology is implied in the wood based industries in this modern arena (Jasmani et al., 2020).

Wood coating

Nano coating of wood-based products is less susceptible to various environmental factors because of the greater surface volume ratio of the coated nanomaterials. The coated nano materials interact with the adverse environmental factors to protect the wood-based product from decay and weathering (Fengel and Wegener, 2003; Hincapié et al., 2015).

Nano additive as a durable enhancement

To increase the durability of wood and wood-based products nanostructures are added by appropriate way. This nano addition creates molecular level changes in the wood-based products. Pathogens like bacteria, fungi and other microorganism ‘scant easily attack on the Nanocoated wood-based products. Different metal oxide nanoparticles such as Zinc oxide (ZnO), cerium oxide (CeO­­2) and titanium oxide (TiO2) were evaluated and find out significant antimicrobial activities (Okyay et al., 2015; Chakra et al., 2017; El-Naggar et al., 2016; Tomak et al., 2018). Graphene, silver and polyurethane Nanoparticles also inhabit the growth of microorganisms on the surface of wood and their products (Wang et al., 2018; Cheng et al., 2016, 2020).

Improvement of mechanical properties by nano addition

The inorganic nanoparticles immersed in the organic polymer increase the mechanical properties. These nanostructures act as a nano filer in the adhesives. nanoparticles like silica and nanocellulose increases hardness, modulus of elasticity (MOE) and modulus of rupture (MOR) significantly (Kong et al., 2019; Fallah et al., 2017).

Improvement of fire retardancy by nano addition

In the modern era, nanostructures are used in pure form or with conventional combination of fire retardants to reduce the ignitability of composite wood products. In this regard titanium oxide (TiO2) nanostructure is reported which reduces the inflammability to larger extent as compared to simple and non-nano based wood products (Deraman and Chandren, 2019). Other nanoparticles reported as fire retardant are zinc-aluminum layered double hydroxide, Nano magnesium aluminum layered double hydroxide and graphene used in wood based products (Yao et al., 2019; Wang et al., 2018; Esmailpour et al., 2020).

UV absorption enhancement by nanoparticles

The UV light coming from the sun rays causes degradation of wood and wood based products and also decreases its water resistance power, because it destroy the polymeric structure of wood (Teacă et al., 2013). To improve the UV resistance of wood and wood based products different techniques have been applied among which the nanotechnology is promising. Different nanostructures such as TiO2 and ZnO are reported which exhibit strong UV resistance properties and color stabilization (Zheng et al., 2015).

Eco-Friendly effects of nanostructures

The human and environment problem related with formaldehyde (HCOH) emission from wood-based panels causes a serious concern globally and many countries issues legislations for this to reduce volatile organic compounds related to wood based panels, the scientific community have to overcome this problem (Ulker et al., 2021). To scavenge formaldehyde emission from wood-based panels nanostructures was added these nanostructures increase the adhesion of formaldehyde (HCOH) in wood-based panels due to its large surface area (Mahrdt et al., 2016).

Conclusions and Recommendations

Nanotechnology use in wood and wood-based products is colossal and enormous. The fate of wood-based industries has been changed by incorporation of nanotechnology globally. Nanotechnology has many advantages such as eco-friendly and its recyclibity in many products. The applications of nanostructures are multipronged and versatile but the present review aim to dig out its use in forest products industries. The addition of nanomaterials to wood based products increase their physico-mechanical properties and increasing the scavenging quality of formaldehyde. The future perspective of nanotechnology is to make the nanocomposite with bio adhesives to eradicate the toxic synthetic polymers and developed the novel bio based nano adhesive for the wood-based products. This will indirectly conserve the forest by increasing the durability of wood-based products.

Acknowledgement

The authors acknowledge the support of DG, PFI peshawar and his team for providing support for the completion of this research project.

Novelty Statement

Nanostructures are transforming composite wood products by enhancing their performance, sustainability, and functionality, thereby driving innovative applications in modern construction and manufacturing

Author’s Contribution

Abdur Rahman Khan: Contributed to the conception and composing of manuscript Also served as corresponding author.

Mansoor Ali Khan: Helped in composition of manuscript and assisted in physio mechanical properties of nanocomposite.

Abdur Rehman: Helped in cross checking for grammatical check.

Muhammad Umair Khan: Proof reading of article and composing of novel statement.

Conflict of interest

The authors have declared no conflict of interest.

References

Alabduljabbar, H., Alyousef, R., Gul, W., Shah, S.R.A., Khan, A., Khan, R. and Alaskar, A., 2020. Effect of alumina nano-particles on physical and mechanical properties of medium density fiberboard. Materials, 13(18): 4207. https://doi.org/10.3390/ma13184207

Bajpai, P., 2016. Pulp and paper industry: Nanotechnology in forest industry: Elsevier. https://doi.org/10.1016/B978-0-12-811099-7.00002-2

Balamurugan, A., Sudha, M., Surendhiran, S., Anandarasu, R., Ravikumar, S. and Khadar, Y.S., 2020. Hydrothermal synthesis of samarium (Sm) doped cerium oxide (CeO2) nanoparticles: characterization and antibacterial activity. Mater. Today Proc., 26: 3588-3594. https://doi.org/10.1016/j.matpr.2019.08.217

Bueno, A.F., Bañón, M.N., De Morentín, L.M. and García, J.M., 2014. Treatment of natural wood veneers with nano-oxides to improve their fire behaviour. Paper presented at the IOP conference series: Materials science and engineering. https://doi.org/10.1088/1757-899X/64/1/012021

Candan, Z. and Akbulut, T., 2015. Physical and mechanical properties of nanoreinforced particleboard composites. Maderas. Cienciay Tecnol., 17(2): 319-334. https://doi.org/10.4067/S0718-221X2015005000030

Carvalho, L., Magalhães, F. and Ferra, J., 2012. Formaldehyde emissions from wood-based panels-Testing methods and industrial perspectives. Formaldehyde: Chem. Appl. Role Polymeriz., pp. 1-45.

Chakra, C., Raob, K. and Rajendar, V., 2017. Nanocomposites of ZnO and TiO2 have enhanced antimicrobial and antibacterial properties than their disjoint counterparts. Dig. J. Nanomater. Biostruct., 12: 185-193. https://doi.org/10.1007/s13205-017-0731-8

Cheng, D., Wen, Y., An, X., Zhu, X. and Ni, Y., 2016. TEMPO-oxidized cellulose nanofibers (TOCNs) as a green reinforcement for waterborne polyurethane coating (WPU) on wood. Carbohydrate Polymers, 151: 326-334. https://doi.org/10.1016/j.carbpol.2016.05.083

Cheng, L., Ren, S. and Lu, X., 2020. Application of eco-friendly waterborne polyurethane composite coating incorporated with nano cellulose crystalline and silver nano particles on wood antibacterial board. Polymers, 12(2): 407. https://doi.org/10.3390/polym12020407

Chernousova, S. and Epple, M., 2013. Silver as antibacterial agent: Ion, nanoparticle, and metal. Angewandte Chem. Int. Ed., 52(6): 1636-1653. https://doi.org/10.1002/anie.201205923

Conner, L. and Madariaga, B., 1996. Economic impact analysis and regulatory flexibility analysis of air pollution regulations: Architectural and industrial maintenance coatings. Draft report: Environmental Protection Agency, Research Triangle Park, NC (United States).

Cornell, R.M. and Schwertmann, U., 2003. The iron oxides: Structure, properties, reactions, occurrences, and uses: Wiley-vch Weinheim. Vol. 664. https://doi.org/10.1002/3527602097

Cristea, M.V., Riedl, B. and Blanchet, P., 2011. Effect of addition of nanosized UV absorbers on the physico-mechanical and thermal properties of an exterior waterborne stain for wood. Prog. Organ. Coat., 72(4): 755-762. https://doi.org/10.1016/j.porgcoat.2011.08.007

De Filpo, G., Palermo, A.M., Rachiele, F. and Nicoletta, F.P., 2013. Preventing fungal growth in wood by titanium dioxide nanoparticles. Int. Biodeter. Biodegrad., 85: 217-222. https://doi.org/10.1016/j.ibiod.2013.07.007

Deraman, A.F. and Chandren, S., 2019. Fire-retardancy of wood coated by titania nanoparticles. Paper presented at the AIP Conference Proceedings. https://doi.org/10.1063/1.5125526

Dukarska, D. and Czarnecki, R., 2016. Fumed silica as a filler for MUPF resin in the process of manufacturing water-resistant plywood. Eur. J. Wood Wood Prod., 74: 5-14. https://doi.org/10.1007/s00107-015-0955-4

El-Naggar, M.E., Shaheen, T.I., Zaghloul, S., El-Rafie, M.H. and Hebeish, A., 2016. Antibacterial activities and UV protection of the in situ synthesized titanium oxide nanoparticles on cotton fabrics. Ind. Eng. Chem. Res., 55(10): 2661-2668. https://doi.org/10.1021/acs.iecr.5b04315

Esmailpour, A., Majidi, R., Taghiyari, H.R., Ganjkhani, M., Mohseni Armaki, S.M. and Papadopoulos, A.N., 2020. Improving fire retardancy of beech wood by graphene. Polymers, 12(2): 303. https://doi.org/10.3390/polym12020303

Fallah, F., Khorasani, M. and Ebrahimi, M., 2017. Improving the mechanical properties of waterborne nitrocellulose coating using nano-silica particles. Progress Organ. Coat., 109: 110-116. https://doi.org/10.1016/j.porgcoat.2017.04.016

Fengel, D. and Wegener, G., 2003. Wood chemistry, ultrastructure, reaction. Remagen: Germany: Kessel Verlag.

Fernández-Puratich, H. and Oliver-Villanueva, J.V., 2014. Quantification of biomass and energetic value of young natural regenerated stands of Quercus ilex under mediterranean conditions. Rev. Bosque, 35(1): 65-74. https://doi.org/10.4067/S0717-92002014000100007

Ganaie, S., Abbasi, T. and Abbasi, S., 2015. Green synthesis of silver nanoparticles using an otherwise worthless weed mimosa (Mimosa pudica): Feasibility and process development toward shape/size control. Partic. Sci. Technol., 33(6): 638-644. https://doi.org/10.1080/02726351.2015.1016644

Global Status Report: Towards a Zero-Emission, Efficient and Resilient Buildings and Construction Sector. 2018. Agency, I.E., Programme, U.N.E., 2018.

González, W., Álvarez, E., Martínez-Martínez, R., Yescas-Mendoza, E., Camarillo, I. and Caldiño, U., 2012. Cold white light generation through the simultaneous emission from Ce3+, Dy3+ and Mn2+ in 90Al2O3· 2CeCl3· 3DyCl3· 5MnCl2 thin film. J. Luminescence, 132(8): 2130-2134. https://doi.org/10.1016/j.jlumin.2012.03.064

Guefrech, A., Mounanga, P. and Khelidj, A., 2011. Experimental study of the effect of addition of nano-silica on the behaviour of cement mortars Mounir. Proc. Eng., 10: 900-905. https://doi.org/10.1016/j.proeng.2011.04.148

Gul, W. and Alrobei, H., 2021. Effect of graphene oxide nanoparticles on the physical and mechanical properties of medium density fiberboard. Polymers, 13(11): 1818. https://doi.org/10.3390/polym13111818

Gul, W., Akbar Shah, S.R., Khan, A., Ahmad, N., Ahmed, S., Ain, N. and Khan, R., 2023. Synthesis of graphene oxide (GO) and reduced graphene oxide (rGO) and their application as nano-fillers to improve the physical and mechanical properties of medium density fiberboard. Front. Mater., 10: 1206918. https://doi.org/10.3389/fmats.2023.1206918

Gul, W., Alrobei, H., Shah, S.R.A. and Khan, A., 2020. Effect of iron oxide nanoparticles on the physical properties of medium density fiberboard. Polymers, 12(12): 2911. https://doi.org/10.3390/polym12122911

Gul, W., Shah, S.R.A., Khan, A. and Pruncu, C.I., 2021. Characterization of zinc oxide-urea formaldehyde nano resin and its impact on the physical performance of medium-density fiberboard. Polymers, 13(3): 371. https://doi.org/10.3390/polym13030371

Hincapié, I., Künniger, T., Hischier, R., Cervellati, D., Nowack, B. and Som, C., 2015. Nanoparticles in facade coatings: A survey of industrial experts on functional and environmental benefits and challenges. J. Nanopart. Res., 17: 1-12. https://doi.org/10.1007/s11051-015-3085-3

Hummers, Jr, W.S. and Offeman, R.E., 1958. Preparation of graphitic oxide. J. Am. Chem. Soc., 80(6): 1339-1339. https://doi.org/10.1021/ja01539a017

Iriarte-Mesa, C., López, Y.C., Matos-Peralta, Y., de la Vega-Hernández, K. and Antuch, M., 2020. Gold, silver and iron oxide nanoparticles: Synthesis and bionanoconjugation strategies aiming to electrochemical applications. Surface-modified nanobiomaterials for electrochemical and biomedicine applications, pp. 93-132. https://doi.org/10.1007/978-3-030-55502-3_4

Issa, I., Joly-Pottuz, L., Réthoré, J., Esnouf, C., Douillard, T., Garnier, V. and Masenelli-Varlot, K., 2018. Room temperature plasticity and phase transformation of nanometer-sized transition alumina nanoparticles under pressure. Acta Mater., 150: 308-316. https://doi.org/10.1016/j.actamat.2018.03.023

Jagiełło, J., Chlanda, A., Baran, M., Gwiazda, M. and Lipińska, L., 2020. Synthesis and characterization of graphene oxide and reduced graphene oxide composites with inorganic nanoparticles for biomedical applications. Nanomaterials, 10(9): 1846. https://doi.org/10.3390/nano10091846

Jasmani, L., Rusli, R., Khadiran, T., Jalil, R. and Adnan, S., 2020. Application of nanotechnology in wood-based products industry: A review. Nanosc. Res. Lett., 15: 1-31. https://doi.org/10.1186/s11671-020-03438-2

Jia, Q., Zeng, J., Qiao, R., Jing, L., Peng, L., Gu, F. and Gao, M., 2011. Gelification: An effective measure for achieving differently sized biocompatible Fe3O4 nanocrystals through a single preparation recipe. J. Am. Chem. Soc., 133(48): 19512-19523. https://doi.org/10.1021/ja2081263

Kevin, E.I., Ochanya, O.M., Olukemi, A.M., Bwanhot, S.T.N. and Uche, I., 2018. Mechanical properties of urea formaldehyde particle board composite. Am. J. Chem. Biochem. Eng., 2(1): 10-15. https://doi.org/10.11648/j.ajcbe.20180201.12

Khanjanzadeh, H., Pirayesh, H. and Sepahvand, S., 2014. Influence of walnut shell as filler on mechanical and physical properties of MDF improved by nano-SiO2. J. Indian Acad. Wood Sci., 11: 15-20. https://doi.org/10.1007/s13196-014-0111-5

Kim, S., 2009. The reduction of indoor air pollutant from wood-based composite by adding pozzolan for building materials. Constr. Build. Mater., 23(6): 2319-2323. https://doi.org/10.1016/j.conbuildmat.2008.11.008

Kong, L., Xu, D., He, Z., Wang, F., Gui, S., Fan, J. and Liu, B., 2019. Nanocellulose-reinforced polyurethane for waterborne wood coating. Molecules, 24(17): 3151. https://doi.org/10.3390/molecules24173151

Li, H., Xiao, H.G., Yuan, J. and Ou, J., 2004. Microstructure of cement mortar with nano-particles. Composit. B: Eng., 35(2): 185-189. https://doi.org/10.1016/S1359-8368(03)00052-0

Li, J., Pan, Y., Xiang, C., Ge, Q. and Guo, J., 2006. Low temperature synthesis of ultrafine α-Al2O3 powder by a simple aqueous sol–gel process. Ceram. Int., 32(5): 587-591. https://doi.org/10.1016/j.ceramint.2005.04.015

Liu, Y., Laks, P. and Heiden, P., 2002. Controlled release of biocides in solid wood. I. Efficacy against brown rot wood decay fungus (Gloeophyllum trabeum). J. Appl. Polymer Sci., 86(3): 596-607. https://doi.org/10.1002/app.10896

Lohcharoenkal, W., Abbas, Z. and Rojanasakul, Y., 2021. Advances in nanotechnology-based biosensing of immunoregulatory cytokines. Biosensors, 11(10): 364. https://doi.org/10.3390/bios11100364

Mahltig, B., Swaboda, C., Roessler, A. and Böttcher, H., 2008. Functionalising wood by nanosol application. J. Mater. Chem., 18(27): 3180-3192. https://doi.org/10.1039/b718903f

Mahr, M.S., Hübert, T., Stephan, I. and Militz, H., 2013. Decay protection of wood against brown-rot fungi by titanium alkoxide impregnations. Int. Biodeter. Biodegrad., 77: 56-62. https://doi.org/10.1016/j.ibiod.2012.04.026

Mahrdt, E., Pinkl, S., Schmidberger, C., van Herwijnen, H.W., Veigel, S. and Gindl-Altmutter, W., 2016. Effect of addition of microfibrillated cellulose to urea-formaldehyde on selected adhesive characteristics and distribution in particle board. Cellulose, 23: 571-580. https://doi.org/10.1007/s10570-015-0818-5

Meng, L.Y., Wang, B., Ma, M.G. and Lin, K.L., 2016. The progress of microwave-assisted hydrothermal method in the synthesis of functional nanomaterials. Mater. Today Chem., 1: 63-83. https://doi.org/10.1016/j.mtchem.2016.11.003

Mukherjee, P., Ahmad, A., Mandal, D., Senapati, S., Sainkar, S.R., Khan, M.I. and Kumar, R., 2001. Fungus-mediated synthesis of silver nanoparticles and their immobilization in the mycelial matrix: A novel biological approach to nanoparticle synthesis. Nano Lett., 1(10): 515-519. https://doi.org/10.1021/nl0155274

Myers, G.E., 1989. Advances in methods to reduce formaldehyde emission. Composite board products for furniture and cabinet-innovations in manufacture and utilization.

Okyay, T.O., Bala, R.K., Nguyen, H.N., Atalay, R., Bayam, Y. and Rodrigues, D.F., 2015. Antibacterial properties and mechanisms of toxicity of sonochemically grown ZnO nanorods. Rsc. Adv., 5(4): 2568-2575. https://doi.org/10.1039/C4RA12539H

Papadopoulos, A.N., 2010. Chemical modification of soild wood and wood raw material for composites production with linear chain carboxylic acid anhydrides. ChemInform, 41(26): i. https://doi.org/10.1002/chin.201026276

Peteu, S.F., Oancea, F., Sicuia, O.A., Constantinescu, F. and Dinu, S., 2010. Responsive polymers for crop protection. Polymers, 2(3): 229-251. https://doi.org/10.3390/polym2030229

Pizzi, A. and Mittal, K.L., 2017. Handbook of adhesive technology: CRC press.

Pluym, T., Powell, Q., Gurav, A., Ward, T., Kodas, T., Wang, L. and Glicksman, H., 1993. Solid silver particle production by spray pyrolysis. J. Aerosol Sci., 24(3): 383-392. https://doi.org/10.1016/0021-8502(93)90010-7

Poshtiri, A.H., Taghiyari, H.R. and Karimi, A.N., 2014. Fire-retarding properties of nano-wollastonite in solid wood. Philipp. Agric. Sci., 97(1): 52-59.

Pourjafar, M., Behrooz, R., Shalbafan, A. and Nayyeri, 2022. Preparation and characterisation of electromagnetic shielding medium-density fiberboard using Iron oxide nanoparticles. Wood Mater. Sci. Eng., pp. 1-20. https://doi.org/10.1080/17480272.2022.2136529

Pourjafar, M., Behrooz, R., Shalbafan, A. and Nayyeri, V., 2023. Preparation and characterisation of electromagnetic shielding medium-density fiberboard using Iron oxide nanoparticles. Wood Mater. Sci. Eng., 18(4): 1360-1371. https://doi.org/10.1080/17480272.2022.2136529

Qu, L., He, C., Yang, Y., He, Y. and Liu, Z., 2005. Hydrothermal synthesis of alumina nanotubes templated by anionic surfactant. Mater. Lett., 59(29-30): 4034-4037. https://doi.org/10.1016/j.matlet.2005.07.059

Rani, H., Singh, S.P., Yadav, T.P., Khan, M.S., Ansari, M.I. and Singh, A.K., 2020. In-vitro catalytic, antimicrobial and antioxidant activities of bioengineered copper quantum dots using Mangifera indica (L.) leaf extract. Mater. Chem. Phys., 239: 122052. https://doi.org/10.1016/j.matchemphys.2019.122052

Rassam, G., Abdi, Y. and Abdi, A., 2012. Deposition of TiO2 nano-particles on wood surfaces for UV and moisture protection. J. Exp. Nanosci., 7(4): 468-476. https://doi.org/10.1080/17458080.2010.538086

Salavati-Niasari, M., Davar, F. and Mazaheri, M., 2008. Preparation of ZnO nanoparticles from [bis (acetylacetonato) zinc (II)]–oleylamine complex by thermal decomposition. Mater. Lett., 62(12-13): 1890-1892. https://doi.org/10.1016/j.matlet.2007.10.032

Salma, U., Chen, N., Richter, D.L., Filson, P.B., Dawson-Andoh, B., Matuana, L. and Heiden, P., 2010. Amphiphilic core/shell nanoparticles to reduce biocide leaching from treated wood, 1–leaching and biological efficacy. Macromol. Mater. Eng., 295(5): 442-450. https://doi.org/10.1002/mame.200900250

Schmalzl, K. and Evans, P., 2003. Wood surface protection with some titanium, zirconium and manganese compounds. Polymer Degrad. Stability, 82(3): 409-419. https://doi.org/10.1016/S0141-3910(03)00193-9

Singh, A.K., Pal, P., Gupta, V., Yadav, T.P., Gupta, V. and Singh, S.P., 2018. Green synthesis, characterization and antimicrobial activity of zinc oxide quantum dots using Eclipta alba. Mater. Chem. Phys., 203: 40-48. https://doi.org/10.1016/j.matchemphys.2017.09.049

Singh, A.K., Yadav, T.P., Pandey, B., Gupta, V. and Singh, S.P., 2019. Engineering nanomaterials for smart drug release: Recent advances and challenges. Appl. Target. Nano Drugs Delivery Syst., pp. 411-449. https://doi.org/10.1016/B978-0-12-814029-1.00015-6

Song, X.L., Qu, P., Yang, H.P., He, X. and Qiu, G.Z., 2005. Synthesis of γ-Al2O3 nanoparticles by chemical precipitation method. J. Central South Univ. Technol., 12: 536-541. https://doi.org/10.1007/s11771-005-0118-6

Sun, Q., Yu, H., Liu, Y., Li, J., Cui, Y. and Lu, Y., 2010. Prolonging the combustion duration of wood by TiO2 coating synthesized using cosolvent-controlled hydrothermal method. J. Mater. Sci., 45: 6661-6667. https://doi.org/10.1007/s10853-010-4758-z

Sun, Q., Yu, H., Liu, Y., Li, J., Lu, Y. and Hunt, J.F., 2010. Improvement of water resistance and dimensional stability of wood through titanium dioxide coating. https://doi.org/10.1515/hf.2010.114

Taghiyari, H., Mobini, K., Sarvari-Samadi, Y., Doosti, Z., Karimi, F., Asghari, M. and Nouri, P., 2013. Effects of nano-wollastonite on thermal conductivity coefficient of medium-density fiberboard. J. Nanomater. Mol. Nanotechnol., 2: 1 of 5, 2. https://doi.org/10.4172/2324-8777.1000106

Taghiyari, H.R. and Norton, J., 2014. Effect of silver nanoparticles on hardness in medium-density fiberboard (MDF). iFor. Biogeosci. For., 8(5): 677. https://doi.org/10.3832/ifor1188-007

Taghiyari, H.R. and Sarvari, S.Y., 2016. Effects of wollastonite nanofibers on fluid flow in medium-density fiberboard. J. For. Res., 27: 209-217. https://doi.org/10.1007/s11676-015-0137-6

Taghiyari, H.R., Ghorbanali, M. and Tahir, P.M., 2014. Effects of the improvement in thermal conductivity coefficient by nano-wollastonite on physical and mechanical properties in medium-density fiberboard (MDF). BioResources, 9(3): 4138-4149. https://doi.org/10.15376/biores.9.3.4138-4149

Tao, A., Sinsermsuksakul, P. and Yang, P., 2006. Polyhedral silver nanocrystals with distinct scattering signatures. Angewandte Chem. Int. Ed., 45(28): 4597-4601. https://doi.org/10.1002/anie.200601277

Teacă, C.A., Roşu, D., Bodîrlău, R. and Roşu, L., 2013. Structural changes in wood under artificial UV light irradiation determined by FTIR spectroscopy and color measurements. A brief review. BioResour., 8(1). https://doi.org/10.15376/biores.8.1.1478-1507

Tien, D., Liao, C., Huang, J., Tseng, K., Lung, J., Tsung, T. and Yu, B., 2008. Novel technique for preparing a nano-silver water suspension by the arc-discharge method. Rev. Adv. Mater. Sci., 18(8): 752-758.

Tobón, J., Payá, J., Borrachero, M. and Restrepo, O., 2012. Mineralogical evolution of Portland cement blended with silica nanoparticles and its effect on mechanical strength. Constr. Build. Mater., 36: 736-742. https://doi.org/10.1016/j.conbuildmat.2012.06.043

Tomak, E.D., Yazici, O.A., Parmak, E.D.S. and Gonultas, O., 2018. Influence of tannin containing coatings on weathering resistance of wood: Combination with zinc and cerium oxide nanoparticles. Polymer Degrad. Stability, 152: 289-296. https://doi.org/10.1016/j.polymdegradstab.2018.03.012

Ulker, O.C., Ulker, O. and Hiziroglu, S., 2021. Volatile organic compounds (VOCs) emitted from coated furniture units. Coatings, 11(7): 806. https://doi.org/10.3390/coatings11070806

Ümit Yalçın, Ö., 2023. Improved properties of particleboards produced with urea formaldehyde adhesive containing nanofibrillated cellulose and titanium dioxide. BioResources, 18(2). https://doi.org/10.15376/biores.18.2.3267-3278

Valle, A.C., Ferreira, B.S., Prates, G.A., Goveia, D. and Campos, C.I.D., 2020. Physical and mechanical properties of particleboard from Eucalyptus grandis produced by urea formaldehyde resin with SiO2 nanoparticles. Engenharia Agrícola, 40(3): 289-293. https://doi.org/10.1590/1809-4430-eng.agric.v40n3p289-293/2020

Wang, J., Li, J., Zhuang, X., Pan, X., Yu, H., Sun, F. and Jiang, Y., 2018. Improved mould resistance and antibacterial activity of bamboo coated with ZnO/graphene. R. Soc. Open Sci., 5(8): 180173. https://doi.org/10.1098/rsos.180173

Wang, X., Kalali, E.N., Xing, W. and Wang, D.Y., 2018. CO2 induced synthesis of Zn-Al layered double hydroxide nanostructures towards efficiently reducing fire hazards of polymeric materials. Nano Adv., 3: 12-17. https://doi.org/10.22180/na221

Wegner, T.H. and Jones, E.P., 2009. A fundamental review of the relationships between nanotechnology and lignocellulosic biomass. Nanosci. Technol. Renew. Biomater., 1: 1-41. https://doi.org/10.1002/9781444307474.ch1

Wegner, T.H. and Jones, P.E., 2006. Advancing cellulose-based nanotechnology. Cellulose, 13: 115-118. https://doi.org/10.1007/s10570-006-9056-1

Wiley, B., Sun, Y., Mayers, B. and Xia, Y., 2005. Shape-controlled synthesis of metal nanostructures: The case of silver. Chem. Eur. J., 11(2): 454-463. https://doi.org/10.1002/chem.200400927

Wu, W., Jing, Y., Zhou, X. and Dai, H., 2011. Preparation and properties of cellulose fiber/silica core shell magnetic nanocomposites. Paper presented at the 16th international symposium on wood, fiber and pulping chemistry proceedings, ISWFPC, Tiajin.

Yalcin, N. and Sevinc, V., 2001. Studies on silica obtained from rice husk. Ceramics Int., 27(2): 219-224. https://doi.org/10.1016/S0272-8842(00)00068-7

Yao, X., Du, C., Hua, Y., Zhang, J., Peng, R., Huang, Q. and Liu, H., 2019. Flame-retardant and smoke suppression properties of nano MgAl-LDH coating on bamboo prepared by an in situ reaction. J. Nanomater., https://doi.org/10.1155/2019/9067510

Zheng, R., Tshabalala, M.A., Li, Q. and Wang, H., 2015. Weathering performance of wood coated with a combination of alkoxysilanes and rutile TiO2 heirarchical nanostructures. BioResour., 10(4): 7053-7064. https://doi.org/10.15376/biores.10.4.7053-7064