ORIGINALS ORIGINALARBEITEN

Nano-zycosil in MDF: gas and liquid permeability

Hamid Reza Taghiyari

Received: 12 October 2012 / Published online: 7 April 2013

� Springer-Verlag Berlin Heidelberg 2013

Abstract Effects of zycosil nanoparticles, with size range

from 20 to 80 nm, on liquid and gas permeability of

medium density fiberboard were studied. Nanozycosil was

used at four consumption levels of 0, 50, 100, and 150 g/kg

dry wood fibers. Density of all treatments was kept con-

stant at 0.67 g/cm3. The obtained results indicated that

addition of zycosil to the mat resulted in a significant

increase in gas permeability due to the lower fiber-content

in the nanozycosil-treated specimens and the consequent

micro-cavities that were formed in the boards. However,

the water-repellant property of zycosil nanoparticles com-

pensated for the micro-cavities to some extent. High cor-

relation was observed between gas and liquid permeability.

The consumption level of 50 g of nanozycosil/kg can be

recommended to improve the impermeability property of

medium density fiberboard to water.

Einfluss von Nano-Zycosil auf die Gas- und Flussig-

keitsdurchlassigkeit mitteldichter Faserplatten

Zusammenfassung Untersucht wurde der Einfluss von

Zycosil-Nanopartikeln mit einer Partikelgroße zwischen 20

und 80 nm auf die Flussigkeits- und Gasdurchlassigkeit von

mitteldichten Faserplatten. Nano-Zycosil wurde in den vier

Dosierungen 0, 50, 100 und 150 g/kg Spantrockengewicht

verwendet. Die Dichte wurde bei allen Behandlungen mit

0,67 g/cm3 konstant gehalten. Die Ergebnisse zeigten,

dass durch Zugabe von Zycosil zum Spankuchen die

Gaspermeabilitat signifikant anstieg. Dies ist auf den

niedrigeren Spananteil in den mit Nano-Zycosil behandelten

Prufkorpern sowie die dadurch in den Platten entstandenen

Mikrohohlraume zuruckzufuhren. Die Mikrohohlraume

wurden zum Teil durch die wasserabweisende Eigenschaft

der Zycosil-Nanopartikel kompensiert. Die Gas- und

die Flussigkeitsdurchlassigkeit waren hoch korreliert. Zur

Verbesserung der Wasserundurchlassigkeit mitteldichter

Faserplatten konnen 50 g/kg Nano-Zycosil empfohlen

werden.

1 Introduction

Wood is frequently modified by engineering processes to

give stiffness or homogeneous mechanical properties

because few species sustain their hygroscopicity level

(Borrega and Karenlampi 2010) or offer radial and axial

uniformity in their produced wood (Akhtari et al. 2012;

Ghorbani et al. 2012; Papadopoulos 2012); the quality of

wood can also be affected by rotation period, mono- or

mixed-species cultivation, light and soil, as well as inter-

action between clone-type and site (Barna 2011; Hering

et al. 2012; Lotfizadeh et al. 2012; Taghiyari et al. 2008,

2010, 2011a, b, c; Wodzicki 2001). Furthermore, the

majority of humans world-wide depend upon wood prod-

ucts harvested from forests (Dykstra 2012); therefore,

efficient use of wood is highly important. In this connec-

tion, composite-boards offer the advantages of a homoge-

neous structure and the use of raw materials without

restrictions as to the shape and size (Grace 2005) and there

are many studies on finding methods for limitation of

formaldehyde emission and improving the quality (Stockel

et al. 2012; Valenzuela 2012). Composite-boards and

profiles are therefore expanding worldwide. In fact, wood-

based composite products are commonly substituted for

H. R. Taghiyari (&)

Wood Science and Technology Department, The Faculty of Civil

Engineering, Shahid Rajaee Teacher Training University,

Shabanloo St., Lavizan, Tehran, Iran

e-mail: htaghiyari@srttu.edu; htaghiyari@yahoo.com

123

Eur. J. Wood Prod. (2013) 71:353–360

DOI 10.1007/s00107-013-0691-6

solid wood in today’s building structures (Eshaghi et al.

2013; Taghiyari 2006). Structural and non-structural

engineered wood composites based on oriented strand-

board (OSB), plywood, medium density fiberboard (MDF),

laminated veneer lumber (LVL), thermoplastic/wood fiber

blends, etc. are now used in both interior and exterior

applications (Laks 2002). The main factors that influence

the properties and quality of the panels are the density of

the panel, geometry, and moisture content of the particles,

the pressing cycle, and the quantity and type of adhesive.

The production of wood composites has increased dra-

matically over the past three decades due to a number of

factors. The changing wood supply, the development of

new composite technologies, and the widespread accep-

tance by architects and builders have each contributed to

the increased wood composite production (Gardner et al.

2003). Their use, however, is often limited due to high

sensitivity to moisture and decay (Baileys et al. 2003), as

well as fire (Awoyemi and Westermark 2005; Awoyemi

2007; Taghiyari 2012b). Therefore, the emergence of new

technologies to produce an increasing array of new wood

composite products has forced the industry to follow up

varied protection processes and/or treatments to protect

these new wood-based products (Kirkpatrick and Barnes

2006). Wood-based composite products offer complexities

and opportunities not found in solid woods. Because there

are many types of wood composite products and manu-

facturing processes, there are a number of ways to apply

treatments to these materials (Gardner et al. 2003). Bio-

cidal protection may be incorporated into solid wood by

pressure/vacuum treatment processes with liquid-based

systems, by surface coatings (dip, spray, or brush), or by

direct placement in the product (such as borate rods). These

strategies are all post-manufacture treatments (PMT), and

the main concern with each of these treatments is chemical

gradients within the product. The advantage of wood-based

composites is that they offer in-process treatment (IPT)

options (incorporation during manufacture), as well as

PMT (Manning 2002). Several common systems for pres-

ervation of composites include: (1) use of pretreated wood;

(2) in-process preservative treatments favored for com-

posites made from flakes, particles, and fibers where the

preservative treatment is incorporated during the manu-

facturing process; (3) post-process preservative treatments

(PMT); and (4) use of recycled treated wood elements in

manufacturing or the use of wood species with a high

natural resistance against biodegradation or fire (Gardner

et al. 2003). It was also indicated that the inherent nature of

wood-based composites allows them to be treated with IPT,

which offers several distinct advantages not found with

solid wood products (Manning 2002). Therefore, different

materials may be easily used to modify and improve some

of the undesirable properties in composite boards or the

production procedure. In this connection, the heat-con-

ductive nature of nanometal particles (Gogoi and Deb

2012; Mahaptra et al. 2012; Narashimha et al. 2011;

Rangavar et al. 2013; Taghiyari 2011a, b, 2012a, b, 2013;

Taghiyari et al. 2012a, b, c, d, e; Rassam et al. 2012;

Wegner and Jones 2006; Wegner et al. 2005; Wisitoraat

et al. 2010; Wu et al. 2012; Yu et al. 2012) was used to

better polymerize the resin in the core of the mat (Tag-

hiyari et al. 2011a), as well as decreasing gas and liquid

permeability (Taghiyari 2011b). Enhancement of the ther-

mal conductivity of common heat transfer fluids when

small amounts of metallic and other nanoparticles were

dispersed in these fluids has also been reported by many

researchers (Gogoi and Deb 2012; Heidarpour et al. 2011;

Prondana et al. 2011; Sadeghi and Rastgo 2012; Soltani-

nezhad and Aminifar 2011). The improving effects of sil-

ver nanoparticles on physical and mechanical properties of

particleboard on an industrial scale as well as its hot-press

time reduction were also reported (Taghiyari et al. 2011a).

However, the effect of zycosil water-repellent property

in medium-density fiberboard (MDF) has not yet been

studied. The present study was therefore conducted to

evaluate if zycosil nanoparticles could significantly con-

tribute to a lower permeability and decrease the penetration

of water in MDF.

2 Experimental

Wood fibers were procured from Sanaye Choobe Khazar

Company in Iran (MDF Caspian Khazar). The fibers com-

prised a mixture of five species of beech, alder, maple,

hornbeam, and poplar from the neighboring forests. Control

boards were 16 mm in thickness and 0.67 g/cm3 in density.

Separate 50 9 50 mm2 specimens were prepared from each

replication to monitor density. The density of the boards

was kept constant for all treatments. The total nominal

pressure of the plates was 160 bars. The temperature of the

plates was fixed at 130 �C. Hot-pressing continued for

8 min. Urea–Formaldehyde resin (UF) was procured from

Sari Resin Manufacturing Company in Sari, Iran. Resin-

content was 10 % based on dry fiber in each treatment; UF-

resin was used with 200–400 cP in viscosity, 47 s of gel

time, and 1.277 g/cm3 in density. Ten boards were made for

each treatment. From each board, 20 permeability speci-

mens were cut from the central part of the board, and 20

other specimens were cut from the marginal part (marginal

parts are considered the 2-cm margins all around each board

which are usually cut-off in most factories).

The nano-zycosil liquid (NZ-liquid) used was the

resultant product of organo silane reacted with organic

reactant, produced in cooperation with Zydex Industries.

Its color was pale yellow, with the flash point at more than

354 Eur. J. Wood Prod. (2013) 71:353–360

123

85 �C and auto-ignition temperature at more than 200 �C,

specific gravity of 1.05 g/mL (at 25 �C), viscosity of

500–1,000 cps (at 25 �C). The nano-zycosil liquid was

comprised of hydroxyalkyl-alkoxy-alkylsilyl compounds

(38–42 %); and the solvent was ethylene glycol

(58–62 %). The size range of nanoparticles was 20–80 nm.

The NZ-liquid was mixed with the resin at the proportion

of 0, 50, 100, and 150 g/kg dry weight basis of fibers. For

each treatment, the weight of NZ-solids was deducted from

the fiber used to keep the density of the boards constant.

The final mixture of NZ ? resin was smoothly sprayed on

the fibers. The pH and viscosity of the resin were kept

constant for all treatments in the present study. Four boards

were manufactured for each treatment. Boards were kept in

a conditioning chamber (25 ± 2 �C, 40 ± 3 % relative

humidity) for 1 month before the liquid and gas perme-

ability specimens were measured.

2.1 Gas permeability measurements

Many techniques have been brought up to measure per-

meability in solid woods and wood-composite materials

(Dashti et al. 2012a, b; Dermoe et al. 2012; Lotfizadeh

et al. 2012). In the present study, gas permeability mea-

surement was carried out by an apparatus designed and

built by the author (Taghiyari 2011b; Taghiyari and Efhami

2011; Taghiyari et al. 2011b, 2012b) equipped with

7-storey automatic-time-measurement device with milli-

second precision (USPTO No. 8,079,249 B2, approved by

The Iranian Research Organization for Scientific and

Technology under certificate No. 47022). Falling-water

volume-displacement method was used to calculate spe-

cific gas permeability values based on the microstructure

porosity of wood (Shi 2007; Siau 1971; Taghiyari et al.

2010; Taghiyari and Sarvari Samadi 2010). Twenty spec-

imens were randomly cut at scattered locations from the

boards of each treatment by a hole-saw. Diameter of

specimens was 17 mm. For each specimen, gas perme-

ability values were measured at seven different water-col-

umn heights, that is seven different vacuum pressures, in a

single run. Internal diameter of the glass tube was 13 mm.

Water level was 15 cm above the starting sensor of the first

time-measurement device (Gas 1). Connection between the

specimen and holder was made fully air-tight. A vacuum-

pressure gauge with milli-bar precision was connected to

the whole structure to monitor pressure gradient (DP) and

vacuum pressure at any particular time as well as height of

water column. Vacuum pressures at the starting and stop-

ping points for each of the seven different water column

heights are listed in Table 1.

Three measurements were taken for each specimen.

Superficial permeability coefficient was then calculated

using Siau’s Equations (Siau 1995) (Eqs. 1, 2). The

superficial permeability coefficients were then multiplied

by the viscosity of air (l = 1.81 9 10-5 Pa s) for the

calculation of the specific permeability (K = kg l).

kg ¼VdCLðPatm � 0:074�zÞ

tAð0:074�zÞðPatm � 0:037�zÞ �0:760mHg

1:013� 106Pað1Þ

C ¼ 1 þ Vrð0:074DzÞVdðPatm � 0:074�zÞ ð2Þ

Where: kg is the specific gas permeability (m3/m), V d = pr2 Dz [r = radius of measuring tube (m)] (m3), C the cor-

rection factor for gas expansion as a result of change in

static head and viscosity of water, L the length of wood

specimen (m), Patm the atmospheric pressure (m Hg), �z the

average height of water over surface of reservoir during

period of measurement (m), t the time (s), A the cross-

sectional area of wood specimen (m2), Dz the change in

height of water during time t (m), Vr is the total volume of

apparatus above point 1 (including volume of hoses) (m3).

2.2 Liquid permeability measurement

Liquid permeability was measured using RILEM test

method II.4 (Fig. 1) according to RILEM Commission 25,

PEM, Test Method 1154 by International Union of Labo-

ratories and Experts in Construction Materials, Systems,

and Structures; penetration tests were conducted under

laboratory conditions according to ASTM E-514. Two

times were measured: (1) The time the first drop of water

falls off the bottom surface of the specimen; (2) The time

the level of water in the RILEM tube lowers by 50 mm in

the tube (that is, 6.6 CC of water). Correlations between

each of the 7 gas permeability times were separately cal-

culated with the-first-drop time as well as 50-mm-lowering

time.

Table 1 Vacuum pressures at starting and stopping points for each

of the seven measuring heights

Tab. 1 Vakuumdrucke bei Beginn und Ende der Versuche mit jeder

der sieben Messhohen

Code of

the 7

water

columns

Height of the

7 water

columns at

starting point

(cm)

Height of the

7 water

columns at

stopping

point (cm)

Starting

point

vacuum

pressure

(minus

milli-bar)

Stopping

point

vacuum

pressure

(minus

milli-bar)

Gas 1 149.5 139.5 155 146.5

Gas 2 134.5 124.5 141.5 132

Gas 3 119.5 109.5 126.5 117

Gas 4 104.5 94.5 112 101.5

Gas 5 89.5 79.5 97.5 86.5

Gas 6 74.5 64.5 82 72

Gas 7 59.5 49.5 66.5 56

Eur. J. Wood Prod. (2013) 71:353–360 355

123

2.3 Statistical analysis

Statistical analysis was conducted using SAS software

program, version 9.1 (2003). Two-way analysis of variance

(ANOVA) was performed to discern significant difference

at the 95 % level of confidence. Grouping was then made

between treatments using the Duncan test. Correlation and

hierarchical cluster analysis, including dendrogram and

using Ward methods with squared Euclidean distance

intervals, was carried out by SPSS/16 (2007).

3 Results and discussion

The amount of NZ-suspension used for each treatment (50,

100, and g/cm3) was deducted from the dried fiber used to

keep the density of the boards constant at 0.67 g/cm3.

Therefore, the volume of wood fibers decreased as the NZ-

content increased from 0 to 150 g/cm3. This resulted in the

wood fibers being less compacted and integrated together

in the MDF-matrix. SEM micrographs showed scattered

micro-cavities in the body of the NZ-treated boards

(Fig. 2b).

The specific gas permeability values measured for the

control boards based on the seven different water columns

(7 different vacuum pressures) indicated no significant

difference between the seven specific permeability values

(Fig. 3). However, significantly high difference was

observed between the central and marginal specimens. This

shows that the margins of the boards were not as uniformly

compact as the central parts. Careful measures should

therefore be taken to sample not from the marginal parts of

composite boards for scientific purposes. Correlation

analysis for the seven different gas permeability times

(central parts of the boards) with the two liquid perme-

ability times showed high significant positive R-square for

all the seven vacuum pressures (Table 2). However, the

seventh vacuum pressure showed the highest R-square

(0.954 for the 1st-drop, and 0.987 for 50-mm lowering

time); so the gas permeability values of this vacuum

pressure was used for reporting purposes in the present

paper. Similar study on the correlation between gas and

liquid permeability of particleboard showed the highest

correlation in the third vacuum pressure (Taghiyari 2011b).

It can therefore be concluded that in MDF where some of

the single fibers may be loose enough to be moved under

high vacuum pressures, lower vacuum pressures (that is,

Gas-7) may give a better scope of the liquid permeability.

The specific gas permeability value of the four treat-

ments showed that control specimens had the lowest spe-

cific gas permeability (0.13 9 10-13 m3/m) and NZ-150

specimens had the highest (0.39 9 10-13 m3/m) (Fig. 4).

The reason for the higher gas permeability of NZ-150 can

be assigned to the lower fiber volume of this treatment. The

micro-cavities in the MDF-matrix facilitated the air flow

(Fig. 2b). However, not much difference was seen in the

gas permeability of NZ-50 and NZ-100, although both

treatments showed higher gas permeability than that of the

control treatment. This may indicate that more NZ-parti-

cles have contributed in binding the fibers together at 100 g

Fig. 1 Liquid permeability

measurement apparatus

(RILEM) (The length of the

circular specimen in the present

study was 16 mm, equal to the

thickness of the MDF boards)

Abb. 1 Apparat zur Messung

der Flussigkeitsdurchlassigkeit

(RILEM) (Die Lange des

runden Prufkorpers betrug

16 mm, entsprechend der Dicke

der MDF-Platten)

356 Eur. J. Wood Prod. (2013) 71:353–360

123

Fig. 2 MDF texture a control

specimen: fibers are integrated

more intensely; b NZ-150: some

void spaces are observed in the

texture leading air to pass

through much easier

Abb. 2 a Struktur der MDF-

Kontrollprobe: Die Spane sind

starker verdichtet; b NZ-150: es

sind einige Hohlraume in der

Struktur zu sehen, durch die die

Luftdurchlassigkeit leichter

erreicht wird

Gas permeability coefficient of control treatment at seven different vacuum pressures

0

0.05

0.1

0.15

0.2

0.25

CC CM CC CM CC CM CC CM CC CM CC CM CC CM

Gas 1 Gas 2 Gas 3 Gas 4 Gas 5 Gas 6 Gas 7

Gas

per

mea

bili

ty

Fig. 3 Specific gas permeability values of the seven different

vacuum pressures for control treatment (9 10-13 m3/m) (CC Control

central specimens, CM control marginal specimens)

Abb. 3 Kennwerte der Gaspermeabilitat der Kontrollplatte bei 7

verschiedenen Vakuumdrucken (9 10-13 m3/m)

Table 2 Correlation analysis of the 7 gas permeability time values of

different water column heights with liquid permeability time values in

the control treatment (1st drop and 50-mm lowering time)

Gas and water permeabilities Gas 1 Gas 2 Gas 3 Gas 4 Gas 5 Gas 6 Gas 7

1st Drop time 0.83 ** (?) 0.86 ** (?) 0.89 ** (?) 0.90 ** (?) 0.91 ** (?) 0.93 ** (?) 0.95 ** (?)

50-mm lowering time 0.89 ** (?) 0.92 ** (?) 0.94 ** (?) 0.95 ** (?) 0.96 ** (?) 0.97 ** (?) 0.99 ** (?)

Gas 1 1 1.00 ** (?) 0.99 ** (?) 0.99 ** (?) 0.98 ** (?) 0.97 ** (?) 0.94 ** (?)

Gas 2 1 1.00 ** (?) 1.00 ** (?) 0.99 ** (?) 0.98 ** (?) 0.96 ** (?)

Gas 3 1 1.00 ** (?) 1.00 ** (?) 0.99 ** (?) 0.98 ** (?)

Gas 4 1 1.00 ** (?) 0.99 ** (?) 0.98 ** (?)

Gas 5 1 1.00 ** (?) 0.99 ** (?)

Gas 6 1 1.00 ** (?)

Gas 7 1

Gas 1–7: The 7 water column heights for measuring gas permeability making 7 vacuum pressures

NS Non significant

(?) Positive correlation

** Correlation is significant at the l % level (2-tailed)

* Correlation is significant at the 5 % level (2-tailed)

Gas Permeability (Gas 7)

0

0.05

0.1

0.15

0.2

0.25

0.3

0.35

0.4

0.45

Control NZ50 NZ100 NZ150

Sp

ecif

ic g

as p

erm

eab

ility A

BB

C

Fig. 4 Specific gas permeability values for control, NZ-50, NZ-100,

and NZ-150 treatments (9 10-13 m3/m) (NZ = nanozycosil)

Abb. 4 Kennwerte der Gaspermeabilitat der Kontrollplatte sowie der

Platten mit 50 (NZ-50), 100 (NZ-100) und 150 (NZ-150) g/kg Nano-

Zycosil (9 10-13 m3/m)

Eur. J. Wood Prod. (2013) 71:353–360 357

123

consumption level of NZ, resulting in more wood fiber-

integration and consequent lowering the gas permeability.

More than this NZ-content, however, resulted in enlarge-

ment of the micro-cavities to the extent that the binding

property of NZ could not compensate for.

NZ-100 treatment showed an overall highest 1st-drop

liquid permeability time, showing the highest imperme-

ability of this treatment against water (Fig. 5). Further-

more, NZ-50 showed the highest impermeability in terms

of 50-mm lowering time (Fig. 6). The highest liquid per-

meability (the lowest times) was observed in NZ-150

treatment, although not much difference was observed in

comparison to control specimens for both liquid perme-

ability times. This shows the impermeability effects of

nanozycosil against water penetration. That is, NZ-150

treatment showed nearly similar liquid permeability atti-

tude towards water to the control treatment, although this

treatment had the most micro-cavities and showed the

highest specific gas permeability. Water-repellant effects of

zycosil nanoparticles were also noticeable in NZ-50 and

NZ-100 treatments, although showing different attitude

towards the two liquid permeability times.

Cluster analysis was carried out based on the specific

gas permeability and the two liquid permeability times

(Fig. 7). Results of this analysis showed an overall simi-

larity between control and NZ-100 treatments. This proves

that zycosil nanoparticles have the potentiality to keep the

permeability properties of MDF constant regardless of the

lower fiber content and more micro-cavities. However, NZ-

150 was clustered quite differently, showing that the NZ-

particles could no longer compensate the effects of micro-

cavities on the permeability values. NZ-50 treatment was

clustered quite differently with the other three treatments.

It can therefore be concluded that this NZ-consumption

level could be recommended to improve impermeability

against water in MDF. The density of all four treatments

was kept constant in the present study to highlight the

water-repellant effects of zycosil nanoparticles. However,

NZ-application without decreasing the wood fiber volume

may be studied to come to a final decision for industrial

purposes.

Liquid permeability (1st drop)

0

2000

4000

6000

8000

10000

12000

14000

Control NZ50 NZ100 NZ150

Sec

on

d

A

B BB

Fig. 5 Liquid permeability of the 1st-drop for the four treatments of

control, NZ-50, NZ-100, and NZ-150 treatments (s) (NZ nanozycosil)

Abb. 5 Flussigkeitspermeabilitat bezogen auf den Beginn des

Abtropfens bei der Kontrollplatte sowie der Platten mit 50, 100 und

150 g/kg Nano-Zycosil

Liquid permeability (50-mm-lowering time)

0

5000

10000

15000

20000

25000

Control NZ50 NZ100 NZ150

Sec

on

d

A

BBCBC

Fig. 6 Liquid permeability of the 50-mm lowering time for the four

treatments of control, NZ-50, NZ-100, and NZ-150 (s) (NZ nano-

zycosil)

Abb. 6 Flussigkeitspermeabilitat bezogen auf die 50 mm-Absen-

kdauer bei der Kontrollpatte sowie der Platten mit 50, 100 und 150 g/kg

Nano-Zycosil

Fig. 7 Cluster analysis based on gas permeability value as well as the two liquid permeability times for the four treatments of control, NZ-50,

NZ-100, and NZ-150 (NZ nanozycosil)

Abb. 7 Clusteranalyse basierend auf den Kennwerten der Gaspermeabilitat und der beiden Flussigkeitsdurchlassigkeitszeiten der Kontrollplatte

sowie der Platten mit 50, 100 und 150 g/kg Nano-Zycosil

358 Eur. J. Wood Prod. (2013) 71:353–360

123

4 Conclusion

1. MDF with lower densities would usually have higher

specific gas permeability values; however, nano-zy-

cosil can alter this trend to some extent.

2. Zycosil water-repellant property decreases water

permeability in MDF to the extent that it even compen-

sates the micro-cavities resulted from the lower fiber-

content.

3. Consumption level of 50 g of zycosil nanoparticles/kg dry

weight fibers may be recommended for industrial pur-

poses to increase impermeability property towards water.

Acknowledgments The author is thankful to Mr. Mohammad Aieni,

the managing director, and Engin. Mohammad Taghi Kazemi, the

production manager, of Sanaye Choobe Khazar Co. (MDF Caspian

Khazar, htp://www.choobekhazar.com), for procurement of the nec-

essary fiber and raw materials for the present research project. The

technical consultancy of Mr. Younes Sarvari Samadi is also appreci-

ated. I am also grateful to Zydex Industries for preparation of Nano-

Zycosil liquid. Last but not least, we pay our tribute to Mr. Majid

Ghazizadeh, the internal sales manager of Pars Chemical Industries

Company, for the procurement of the resin for the present study.

References

Akhtari M, Ghorbani Kokandeh M, Taghiyari HR (2012) Mechanical

properties of Paulownia fortune wood impregnated with silver,

copper, and zinc oxide nanoparticles. J Trop Forest Sci

24(4):507–511

Awoyemi L (2007) Determination of optimum borate concentration

for alleviating strength loss during heat treatment of wood.

Wood Sci Technol 42:39–45

Awoyemi L, Westermark U (2005) Effects of borate impregnation on

the response of wood strength to heat treatment. Wood Sci

Tchnol 39:484–491

Baileys JK, Marks BM, Ross AS, Crawford DM, Krzysik AM, Muehl

JH, Youngquist JA (2003) Providing moisture and fungal

protection to wood-based composites. Forest Prod J 53(1):76–81

Barna M (2011) Natural regeneration of Fagus sylvatica L.: a review.

Austrian J Forest Sci 128(2):71–91. ISSN: 03795292

Borrega M, Karenlampi PP (2010) Hygroscopicity of heat-treated

Norway spruce (Picea abies) wood. Eur J Wood Prod 68:233–235

Dashti H, Salehpur SH, Taghiyari HR, Akbari F, Heshmati S (2012a)

The Effect of nanoclay on the mass transfer properties of plywood.

Digest J Nanomater Biostructures (DJNB) 7(3):853–860

Dashti H, Shahverdi M, Taghiyari HR, Salehpur Sh, Heshmati S

(2012b) Effects of steaming and microwave pretreatments on

mass transfer characteristics of Aleppe oak (Quercus infectoria).

BioResources 7(3):3262–3273

Dermoe D, Zillig W, Carmeliet J (2012) Variation of measured cross-

sectional cell dimensions and calculated water vapor permeabil-

ity across a single growth ring of spruce wood. Wood Sci

Technol 46:827–840

Dykstra DP (2012) Has reduced-impact logging outlived its useful-

ness? J Trop Forest Sci 24(1) Guest Editorial

Eshaghi S, Faezipour M, Taghiyari HR (2013) Investigation on lateral

resistance of joints made with drywall and sheet metal screws in

bagasse particleboard and comparison with that of commercial

MDF. Maderas-Cienc Tecnol; 15(2) (in press)

Gardner DJ, Tascioglu C, Walinder MEP (2003) Wood composite

protection. In: B. Goodell, DD Nicholas, TP Schultz (eds) Wood

deterioration and preservation: advances in our changing World.

American Chemical Society, Washington, DC, pp 399–419

Ghorbani M, Akhtari M, Taghiyari HR, Kalantari A (2012) Effects of

silver and zinc-oxide nanoparticles on gas and liquid permeabil-

ity of heat-treated Paulownia wood. Austrian J Forest Sci

129(1):106–123

Gogoi M, Deb P (2012) Light scattering behavior of magnetic field

induced directional self assembly of iron oxide nanoparti-

cles suspension. NANO J 7(4):1250027. doi:10.142/S179329

2012500270

Grace JK (2005) Termite response to agricultural fiber composites:

Bagasse. The 36th Annual Meeting of IRG/WP 05-10549,

Bangalore, India

Heidarpour F, Wan WA, Karimi Ghani AB, Bin Ahmadun FR, Sobri

S, Zargara M, Mozafari MR (2011) Nano silver-coated poly-

propylene water filter: I. Manufacture by electron beam gun

using a modified balzers 760 machine. Digest J Nanomater

Biostructures 5(3):787–796

Hering S, Keunecke D, Niemz P (2012) Moisture-dependent ortho-

tropic elasticity of beech wood. Wood Sci Technol 46:927–938

Kirkpatrick JW, Barnes HM (2006) Biocide treatments for wood

composites—a review. The International Research Group on

Wood Protection, IRG/WP 06-40323

Laks PE (2002) Biodegradation susceptibility of untreated engineered

wood products. In: Enhancing the Durability of Lumber and

Engineered Wood Products. FPS Symposium Proceedings No.

7249. Forest Products Society, Madison, pp 125–130

Lotfizadeh H, Shahverdi M, Dashti H, Taghiyari HR (2012) Potential

usage of nanotechnology in wood drying: treating poplar boards

with nanometals affects the drying behavior. Digest J Nanomater

Biostructures 7(3):2309–2319

Mahaptra DR, Willatzen M, Melnik RVN, Lassen B (2012) Modeling

heterostructures with Schroedinger–Poisson–Navier interactive

schemes, effects of carrier charge, and influence of electrome-

chanical coupling. NANO J 7(4):1250031. doi:10.1142/S17932

92012500312

Manning MJ (2002) Wood protection processes for engineered wood

products. In: Enhancing the durability of lumber and engineered

wood products. FPS Symposium Proceedings. Forest Products

Society: Madison, pp 131–136

Narashimha G, Praveen B, Mallikarjuna K, Deva Prasad Raju B

(2011) Mushrooms (Agaricus bisporus) mediated biosynthesis of

silver nanoparticles, characterization and their antimicrobial

activity. Int J Nano Dim 2(1):29–36

Papadopoulos A (2012) Sorption of acetylated pine wood decayed by

brown rot, white rot, and soft rot: different fungi—different

behavior. Wood Sci Technol 46:919–926

Prondana M, Ionita D, Ungureanu C, Bojin D, Demetrescu I (2011)

Enhancing antibacterial effect of multiwalled carbon nanotubes

using silver nanoparticles. Digest J Nanomater Biostructures

6(2):549–556

Rangavar H, Taghiyari HR, Mehr M (2013) Effects of nanocopper on

physical and mechanical properties of MDF. J Trop Forest Sci

(Accepted)

Rassam Gh, Ghofrani M, Taghiyari HR, Jamnani B (2012) Mechan-

ical performance and dimensional stability of nano-silver

impregnated densified spruce wood. Eur J Wood Prod 70:595–

600

Sadeghi B, Rastgo S (2012) Study of the shape controlling silver

nanoplates by reduction process. Int J Bio-Inorg Hybrid Nano-

mater 1(1):33–36

Shi SHQ (2007) Diffusion model based on Fick’s second law for the

moisture absorption process in wood fiber-based composites: is it

suitable or not? Wood Sci Technol 41:645–658

Eur. J. Wood Prod. (2013) 71:353–360 359

123

Siau JF (1971) Flow in Wood. Syracuse University Press, Syracuse,

p 131

Siau JF (1995) Wood: influence of moisture on physical properties.

Department of Wood Science and Forest Products Virginian

Polytechnic Institute and State University, Blacksburg, pp 1–63

Soltaninezhad M, Aminifar A (2011) Study nanostructures of

semiconductor zinc oxide (ZnO) as a photocatalyst for the

degradation of organic pollutants. Int J Nano Dim 2(2):137–145

Stockel F, Konnerth J, Moser J, Kantner W, Gindl-Altmutter W

(2012) Micromechanical properties of the interphase in pMDI

and UF lines. Wood Sci Technol 46:611–620

Taghiyari HR (2006) English for Special Purpose: Wood and Paper

Sciences and Technology; Karafarinan Publication Organization,

ESBN: 964-7284-50-0, p.p. 205

Taghiyari HR (2011a) Study on the effect of nanosilver impregnation

on mechanical properties of heat-treated Populus nigra. Wood

Sci Technol 45:399–404

Taghiyari HR (2011b) Effects of nano-silver on gas and liquid

permeability of particleboard. Digest J Nanomater Biostructures

(DJNB) 6(4):1509–1517

Taghiyari HR (2012a) Correlation between gas and liquid perme-

abilities in some nanosilver-impregnated and untreated hard-

woods. J Trop Forest Sci (JTFS) 24(2):249–255

Taghiyari HR (2012b) Fire-retarding properties of nano-silver in solid

woods. Springer: Wood Sci Technol 46:939–952

Taghiyari HR (2013) Effects of heat-treatment on permeability of

untreated and nanosilver-impregnated native hardwoods. Made-

ras-Cienc Tecnol 15(2) (in press)

Taghiyari HR, Efhami D (2011) Diameter increment response of

Populus nigra var. betulifolia induced by alfalfa. Austrian J

Forest Sci 128(2):113–127

Taghiyari HR, Sarvari Samadi Y (2010) Ultimate length for reporting

gas permeability of Carpinus betulus wood. Special Topics Rev

Porous Media 1 (4):345–351. doi:10.1615/SpecialTopicsRev

PorousMedia.v1.i4.60 (Begell House, inc. publishers)

Taghiyari HR, Parsapajouh D, Karimi AN, Pourtahmasi K (2008)

Evaluation of Fiber Characteristics in the Juvenile wood and

mature wood of Populus deltoids (69) and Populus 9 euro-americana (214), grown in Gillan Province, Iran. Iran J Nat

Resour 61(3):713–722

Taghiyari HR, Karimi AN, Parsapajouh D, Pourtahmasi K (2010).

Study on the longitudinal gas permeability of juvenile wood and

mature wood. Special Topics Rev Porous Media 1(1):31–38. doi:

10.1615/SpecialTopicsRevPorousMedia.v1.i1.30 (Begell House,

inc. publishers)

Taghiyari HR, Rangavar H, Farajpour Bibalan O (2011a) Nano-silver

in particleboard. BioResources 6(4):4067–4075

Taghiyari HR, Efhami D, Karimi AN, Pourtahmasi K (2011b) Effect

of initial spacing on gas permeability of Populus nigra Var.

betulifolia. J Trop Forest Sci 23(3):305–310

Taghiyari HR, Talaei A, Karimi A (2011c) A correlation between the

gas and liquid permeabilities of beech wood heat-treated in hot

water and steam mediums. Maderas Ciencia tecnologia 13(3):

329–336

Taghiyari HR, Rassam Gh, Lotfinejad Sani Y, Karimi A (2012a)

Effects of nano-silver impregnation on some mechanical prop-

erties of ice-blasted specimens prepared from two native species.

J Trop Forest Sci (JTFS) 24(1):83–88

Taghiyari HR, Gholamiyan H, Karimi A (2012b) Effects of heat-

treatment on screw and nail withdrawal resistance of nanosilver-

impregnated and untreated solid woods. Curr Nanosci 8:637–642

Taghiyari HR, Layeghi M, Aminzadeh Liyafooee F (2012b) Effects

of dry ice on gas permeability of nano-silver-impregnated

Populus nigra and Fagus orientalis. IET Nanobiotechnology,

NBT20110048.3d. doi:10.1049/iet.nbt.2011.0048

Taghiyari HR, Enayati A, Gholamiyan H (2012d) Effects of nano-

silver impregnation on brittleness, physical and mechanical

properties of heat-treated hardwoods. Wood Sci Technol. doi:

10.1007/s00226-012-0506-7

Taghiyari HR, Rangavar H, Noori P (2012e) Nano-Wollastonite in

MDF, Part I: Fire-Retarding Properties. Eur J Wood Prod

(Submitted)

Valenzuela J, von Leyser E, Pizzi A, Westermeyer C, Gorrini B

(2012) Industrial production of pine tannin-bonded particleboard

and MDF. Eur J Wood Prod 70(5):735–740

Wegner TH, Jones P (2006) Advancing cellulose-based nanotechnol-

ogy. Cellulose 13:115–118

Wegner TH, Winandy JE, Ritter MA (2005) Nanotechnology

opportunities in residential and non-residential construction. In:

2nd International Symposium on Nanotechnology in Construc-

tion, Bilbao, Spain

Wisitoraat A, Pimtara I, Phokharatkul D, Jaruwongrangsee K,

Tuantranont A (2010) Zinc oxide nanopolypods synthesized by

thermal evaporation of carbon nanotubes and zinc oxide mixed

powder. Current Nanoscience 6(1):45–53

Wodzicki TJ (2001) Natural factors affecting wood structure. Wood

SciTechnol 35:5–26

Wu C, Li F, Zhang Y, Wang L, Guo T (2012) Enhanced field

emission performance of tetrapod-liked zinc oxide nanoneedlesby coating with graphene oxide sheets. Curr Nanosci 8(1):23–25

Yu Y, Jiang Z, Wang G, Tian G, Wang H, Song Y (2012) Surface

functionalization of bamboo with nanostructured ZnO. Wood Sci

Technol 46:781–790

360 Eur. J. Wood Prod. (2013) 71:353–360

123