DOI: 10.3303/CET2292112 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Paper Received: 27 December 2021; Revised: 8 March 2022; Accepted: 12 May 2022 
Please cite this article as: Damasco I.Y., Gallawan J.M.M., Lawagon C.P., 2022, Synthesis of Nanocellulose from Durian Rinds for the 
Preparation of a Self-healing Smart Concrete with Augmented Mechanical Properties, Chemical Engineering Transactions, 92, 667-672  
DOI:10.3303/CET2292112 
  

 CHEMICAL ENGINEERING TRANSACTIONS  
 

VOL. 92, 2022 

A publication of 

 

The Italian Association 

of Chemical Engineering 

Online at www.cetjournal.it 

Guest Editors: Rubens Maciel Filho, Eliseo Ranzi, Leonardo Tognotti 

Copyright © 2022, AIDIC Servizi S.r.l. 

ISBN 978-88-95608-90-7; ISSN 2283-9216 

Synthesis of Nanocellulose from Durian Rinds for the 

Preparation of a Self-healing Smart Concrete with Augmented 

Mechanical Properties 

Ivanbert Y. Damascoa, James Mark M. Gallawana,b, Chosel P. Lawagona,b,* 

a Chemical Engineering, College of Engineering Education, University of Mindanao, Davao City 8000, Philippines 
b Center of Green Nanotechnology Innovations for Environmental Solutions, Research and Publication Center, University of 

Mindanao, Davao City 8000, Philippines 

clawagon@umindanao.edu.ph 

Self-healing encapsulation for concrete repair is a technology that has been in considerable attention recently. 

Encapsulation permits an active substance to be immobilized, protected, released, and functionalized. Herein, 

nanocellulose from durian (Durio zibethinus) rinds were prepared to encapsulate silica, the primary self-healing 

agent. The investigation focused on the augmentation of encapsulated self-healing material-containing 

concrete’s mechanical properties. The synthesized durian nanocellulose (DNC) has a sheet-like morphology, 

whereas the encapsulated silica has a rough surface morphology based on the SEM micrographs. DNC and 

urea-formaldehyde (UF) were used to encapsulate silica, and the synthesized composite (DNC-UF@SiO2) was 

mixed in a cementitious matrix to test its self-healing properties. Results showed that the addition of the self-

healing material augmented the mechanical properties of concrete in both the pristine condition and healed 

samples. Notably, the DNC-UF@SiO2 showed better mechanical performance and lower water absorption than 

UF encapsulated SiO2. Hence, the prepared encapsulated self-healing material embedded in concrete showed 

significant healing potential concerning compressive and tensile strengths after damage, surpassing control 

specimens. Finally, a synthesis procedure was developed to prepare nanocellulose from durian rinds and 

encapsulate silica, showing a potential upcycling route of waste durian rinds for construction materials. 

1. Introduction 

Concrete is one of the most utilized structural materials in building and construction (Mullem et al., 2020). 

However, concrete composites inevitably develop cracks due to temperature fluctuations, external loads, and 

other external factors (Manvith Kumar Reddy et al., 2020). These concrete cracks are hard to detect (Kessler, 

2007), difficult, and are costly to repair (García Calvo et al., 2018). For instance, a staggering £40 billion of 

annual expenditures for structural maintenance were made in the UK alone (Chindasiriphan et al., 2020). In 

addition, repair, maintenance, and damaged concrete infrastructure replacements cover half of the EU's 

infrastructure budget (Gardner et al., 2018). Consequently, cracked concrete has a significant probability of 

deteriorating, resulting in a decrease in the integrity and stability of a concrete infrastructure, posing a 

considerable threat to its durability and safety (Cui,J., 2016). The development of a material that can 

instantaneously repair the cracks the instant it begins to appear would be a viable solution. It would induce 

operational cost, structural maintenance, and repair cost and significantly increase the durability and service life 

of the infrastructure (Gardner et al., 2018). Its ability to heal or repair itself when the material is damaged or 

when its degradation initiates open several significant construction materials applications (Tan et al., 2016). 

When damage is created, various smart materials can automatically heal themselves, such as bacteria-based 

self-healing concrete (Tan et al., 2020) and microcapsule-based self-healing concrete (Manoj Kumaar & 

Mageswari, 2021). For instance, microcapsule self-healing composites have gotten a lot of attention for their 

potential use in cement-based materials (Wang et al., 2021) and their industrial commercialization practicality 

(Tan et al., 2016). Various materials were used to synthesize the encapsulated self-healing composites for 

autogenous healing of concrete (Hassan et al., 2016). However, the amounts of the components in the 

667



encapsulated self-healing system and their effects on concrete's basic and self-healing capabilities necessitates 

further investigation (Wang et al., 2021). Consequently, there is an increase in research about composites 

reinforced with nanocellulose fibers from various sources. However, there is still less study on determining the 

potential of durian rinds as a composite reinforcement source (Rahman et al., 2016). Moreover, there is a 

prevalent high consumption of durian in the Philippines, especially in Davao City, which generates a high number 

of durian rinds wastes. For instance, Davao City is considered one of the world's largest durian producers (Lubis 

et al., 2018). It leads to massive quantities of unprocessed durian rinds waste which could be a potential source 

of a sustainable nanocellulose reinforcement material. 

This study focuses on the synthesis of nanocellulose from Durian rinds and utilizes it to encapsulate concrete 

self-healing material. Silica acts as the self-healing agent and urea-formaldehyde augmented with durian 

nanocellulose (DNC) as a polymeric shell coating. The synthesized encapsulated self-healing material was used 

as a cement additive to prepare the self-healing concrete.  

2. Materials and Methods 

2.1 Materials 

Sodium hydroxide (NaOH, AR ACS,Reagent Grade, Scharlau), sodium chloride (NaCl,Reagent Grade,99.5 %, 

Scharlau), glacial acetic acid (CH₃COOH,MW 60.05, 99.7 %, Panreac Quimica Sau, Spain), and sulfuric acid 

(H₂SO₄, MW 98.080, 95-97 %, AR ACS, Macron Fine Chemicals, Thailand)  were used for the extraction of 

nanocellulose from durian husk. Durian husks were procured from a local wet market in Davao City. Sodium 

metasilicate (Na2SiO3, ERN Chemical Industry) and hydrochloric acid (HCl, 36.5-38 %, Scharlau) were used to 

synthesize silica. Urea-formaldehyde (0 ≤ x < 0,1, Unicol srl, Fontanelle, Italia) and as-prepared nanocellulose 

were used to encapsulate silica. 

2.2 Characterization 

Surface morphologies of the synthesized materials were observed under Scanning Electron Microscope 

(ThermoScientific Quanta 250FEG SEM-EDX, USA). The SEM was equipped with an Energy Dispersive X-ray 

Spectrometer (EDX) for the self-healing material's elemental (C, Si, O, N) mapping. Thermogravimetric analysis 

(Mettler Toledo, DSC823e) was used to determine the material’s stability and the actual encapsulation content. 

2.3 Preparation of Raw Material 

Procured durian rinds were washed to remove excess organic residue before cutting into smaller sizes. Then, 

the durian rinds were boiled until softened to remove the remaining durian scums. The softened durian rinds 

were crushed and washed, extracting the durian fibers (DF). The extracted DF were dried in a drying oven at 

80 oC for at least two (2) days or until completely dried. Dried DF were crushed using a pulverizer (RRH-200, 

High-Speed Multifunction Comminutor, 28000 rpm) and were segregated according to different mesh sizes.  

2.4 Synthesis of Durian nanocellulose (DNC) 

The extracted DF was treated with sodium hydroxide (NaOH, 2 % solution) for four (4) hours at 100 oC under 

constant stirring (70 rpm). It was filtered and washed several times with deionized (DI) water until neutral pH 

was reached. The residue was then dried in a drying oven at 80 oC for 24 hours. The treated DF was crushed 

again using a mechanical pulverizer and bleached using a mixture of NaCl (22.5 g) and CH₃COOH (7.5 mL) in 

1.5 L of DI water under constant mechanical stirring at 70 oC for two (2) hours. After the bleaching process, DF 

was filtered, washed several times with DI water until a neutral pH, and dried (80 oC for 24 hours). Bleached DF 

was then crushed using a pulverizer, and treated with 64 % H₂SO₄ (1 g DF/30 mL H₂SO₄) under constant 

mechanical stirring at 40 oC for 30 minutes. Subsequently, the resulting suspension was immediately diluted 

with DI water (10 times of H₂SO₄ solution) to cease the acid hydrolysis process. The resulting suspension was 

then centrifuged (Table Top Laboratory Centrifuge, Digisystem Laboratory Instruments Inc., 3200 rpm) to 

remove the excess acid for 10 mins. To remove the non-reactive sulfate group, soluble sugars, and salts, the 

treated DF underwent dialysis for 48 hours or until a neutral pH was attained. Then, the DNC produced was 

sonicated for 5 mins, filtered, washed, and oven-dried (80 oC for 24 hours). 

2.5 Synthesis of DNC encapsulated SiO2 

Sodium metasilicate was dissolved in DI water (37.5 wt. %) and continuously mixed until crystal clear-like 

texture. Hydrochloric acid (38 wt. %) was added dropwise to the solution while constantly stirring until a stable 

gel-aqueous solution was achieved. The solution was then stabilized by mixing for another 15 minutes. 

Nanocellulose dissolved in DI water (12 wt. %) was added dropwise to the gel-aqueous mixture while stirring 

668



(60 oC). A urea-formaldehyde (UF) solution (38 wt. %) was also added dropwise, and the final solution was 

stirred for 2 hours. It was then filtered, washed with DI until neutral, and oven-dried (80 oC for 12 h). 

2.6 Preparation of concrete samples 

Materials needed for concrete mixing were based on the ACI 211.1-91 to determine the mass weight. Coarse 

and fine aggregates were immersed in water for at least 24h beforehand to achieve saturated surface dry 

condition during batching. Cement, water, and admixture were initially added by interval to ensure homogeneous 

dispersion by ½ of the dry mixture for an interval of 3 minutes. After forming a cement paste, coarse and fine 

aggregates were hand-mixed until thoroughly blended. The freshly mixed concrete was then placed into the 

concrete molds. Two layers were required for less than 100mm cube and with the help of a tamping rod to allow 

consolidation. Lastly, the sample was dried for 24h ± 4 h before removing it from the concrete mold to start 

curing the concrete specimen. 

2.7 Mechanical tests of concrete samples 

A compressive testing machine (UTM Shimadzu, UMH100) was used to evaluate the compressive strength of 

concrete samples prepared in this study (ASTM C109/C109M). The minimum required curing days for 

compressive strength testing were 7 and 28 days in accordance with ASTM C192 / C192M-19. The calculation 

of the compressive strength (fm, MPa) is the total maximum load (P, N) divided by the area of the loaded surface 

(A, mm2).  

2.8 Water absorption test 

The cracked concrete specimens were exposed to a controlled environment (temperature 25 oC, relative 

humidity > 95 %). Water absorption by capillarity (ASTM C1585) was performed after 28 days of exposure. 

3. Results and Discussion 

3.1 Characterization 

Fibers were extracted from durian rinds and pre-treated before utilization for nanocellulose synthesis. The DF’s 

surface morphology is fibrous and rod-like (Figure 1a). On the other hand, the DNC’s morphology (Figure 1b) 

depicts nanofibrous cellulose (Mazela et al., 2020), where tangled fibers formed into thin sheet-like structures. 

The sheet-like morphology is beneficial for its utilization in encapsulating the self-healing material. 

 

Figure 1: SEM micrographs of (a) extracted fiber and (b) nanocellulose from durian rinds. 

The self-healing agent (SiO2) encapsulation was done using urea-formaldehyde (UF) and DNC. The UF 

encapsulated SiO2 (UF@SiO2) resembles aggregated particles with a rough surface (Figure 2a). The roughness 

texture may help in its adherence to the cement paste. Its EDX analysis (Figure 2b) detected the presence of 

C, O, N, and Si. Si and O are due to SiO2, whereas C, N, O are due to UF. Furthermore, the DNC and UF 

encapsulated SiO2 (DNC-UF@SiO2) has a morphological structure (Figure 2c) similar to that of UF@SiO2, and 

EDX analysis (Figure 2d) showed an increased presence of C and O due to the added DNC. The detected Na 

is a by-product of the SiO2 synthesis (Na2SiO3 + 2HCl → 2NaCl + H2O + SiO2), albeit just a minimal amount. 

The amount of UF and DNC that encapsulated SiO2 can be calculated using the TGA analysis (Figure 3). The 

SiO2 nanoparticles have a slight weight loss of 1.04 %, occurring at 400 oC due to some organic impurities. The 

UF@SiO2 weight loss is 12.63 %, which UF accounts for 11.59 %. It is slightly lower than the actual amount of 

UF (13.92 %) used, which means that around 2.33% UF is lost during the encapsulation process. As for the 

DNC-UF@SiO2, weight loss is 14.36 %, which entails that the actual amount of DNC and UF is 13.32 %.  

669



Half of the amount of UF was replaced by DNC in the encapsulation process, which is more efficient, resulting 

in a material loss of just 0.6 %. Furthermore, mass loss below 200 oC can be attributed to moisture loss, then 

gradual thermal decomposition of encapsulating material (UF and DNC) above 200 oC and faster decomposition 

rate at above 400 OC. Nevertheless, both UF@SiO2 and DNC-UF@SiO2 showed thermal stability until 200 oC, 

which is already beneficial for application in concrete. 

 

 

Figure 2: SEM micrographs and EDX analysis of (a, b) UF encapsulated SiO2 (UF@SiO2), (c, d) DNC-UF 

encapsulated SiO2 (DNC-UF@SiO2). 

 
Figure 3: Thermogravimetric analysis of SiO2 nanoparticles, UF-encapsulated SiO2 (UF@SiO2), and DNC-UF 

encapsulated SiO2 (DNC-UF@SiO2). 

3.2 Mechanical Properties 

Concrete samples were prepared using the encapsulated self-healing material (5.0 wt. % with respect to 

cement) and subjected to tensile (T) and compressive (C) strength test. Also, the addition of the synthesized 

SiO2 in the cement mixture resulted in an increase in mechanical properties (8.2 % T, 32.7% C) compared to 

the reference samples (REF, without additive). This increase can be attributed to the reinforcing effect of silica 

on the cementitious matrix (Tan et al., 2016). A slight increase also is observed for UF@SiO2 and DNC-

UF@SiO2 concrete samples, noting that the latter has a better mechanical response. The partial replacement 

of UF with DNC may have resulted in better adhesion to the cement mixture since DNC is inherently more 

hydrophilic than UF and has rough surface. A similar trend is also observed in the healed concrete samples. A 

slight increase was also observed in the mechanical properties of healed concrete samples with varying self-

healing materials: SiO2 (5.1 % T, 60.1 % C), UF@SiO2 (3.9 % T, 4.5 % C), and DNC-UF@SiO2 (5.5 % T, 7.1 % 

C). Hence, encapsulating the self-healing material resulted in better mechanical responses and would benefit 

long-term adherence in concrete before cracks may occur. 

670



 

Figure 4: (a) Compressive and (b) tensile strength of pristine and healed concrete at 28 days. 

3.3 Water absorption by capillarity 

The water absorption results of healed concrete with self-healing materials showed lower absorption values 

than the reference sample. It indicates that self-healing materials improve the interaction of the hydrated 

compounds inherently found in concrete and form new products to heal the crack (Chindasiriphan et al., 2020). 

DNC-UF@SiO2 has the lowest water absorption values indicating that the hydrophilic properties of DNC may 

have helped in the healing process, especially that water is critical for self-healing to occur (Hassan et al., 2016). 

 

Figure 5: Water absorption by capillarity of cracked concrete samples after 28 days. 

3.4 Optical microscopy of self-healed concrete 

Autogenous healing of concrete due to continuous cement hydration may have occurred in the healed samples, 

given the improvement of their mechanical properties. As confirmed by the SEM-EDX analysis (Figure 6), 

healing products filled the cracked area, which resulted in an improved mechanical response. Occurrence of Na 

and Al are observed in the healed area (Figure 6 inset EDX result), indicating the possible presence of albite 

(NaAlSi3O8). Hence, there was an interaction between the encapsulated silica and the hydrated compounds in 

the cementitious matrix. 

 

Figure 6: (a) Optical micrographs and EDX analysis of self-healed concrete with DNC-UF@SiO2. 

671



4. Conclusions 

Encapsulation of SiO2 using DNC was successfully done, providing better mechanical properties to the healed 

samples. Concrete samples with self-healing material have better mechanical properties than reference 

samples. Also, healed concrete has slightly better mechanical performance than pristine samples. Hence, the 

prepared encapsulated self-healing material augmented and healed the mechanical properties of cracked 

concrete. In the future, optimization of the amount of self-healing material added to the cement mixture must be 

done, given the successful demonstration of the healing property of DNC-UF@SiO2. Also, elucidation on the 

long-term stability of DNC component in concrete must also be investigated. 

Acknowledgments 

This study was supported by the Department of Science and Technology – Philippine Council for Industry, 

Energy, and Emerging Technology Research and Development (DOST-PCIEERD) through the Young 

Innovators Program (YIP). 

References 

Chindasiriphan P., Yokota H., Pimpakan P., 2020, Effect of fly ash and superabsorbent polymer on concrete 

self-healing ability, Construction and Building Materials, 233, 116975.  

Cui, J. (2016). Effect of chemical admixture on durability of concrete. Chemical Engineering Transactions, 

55(1994), 439–444.  

García Calvo J. L., Pérez G., Carballosa P., Erkizia E., Gaitero J. J., & Guerrero A., 2019, The effect of 

nanoparticles on the self-healing capacity of high performance concrete, In Nanotechnology in Eco-efficient 

Construction: Materials, Processes and Applications. Elsevier Ltd., 43-67. 

Gardner D., Lark R., Jefferson T., Davies R., 2018, A survey on problems encountered in current concrete 

construction and the potential benefits of self-healing cementitious materials, Case Studies in Construction 

Materials, 8, 238–247.  

Hassan M. M., Milla J., Rupnow T., Al-Ansari M., Daly W. H., 2016, Microencapsulation of calcium nitrate for 

concrete applications, Transportation Research Record, 2577, 8–16.  

Kessler M. R., 2007, Self-healing: A new paradigm in materials design, Proceedings of the Institution of 

Mechanical Engineers, Part G: Journal of Aerospace Engineering, 221(4), 479–495.  

Lubis R., Saragih S. W., Wirjosentono B., Eddyanto E., 2018, Characterization of durian rinds fiber (Durio 

zubinthinus, murr) from North Sumatera, AIP Conference Proceedings, 2049 (1), 020069.  

Manoj Kumaar C., Mageswari M., 2021, Thermal analysis on self-healing concrete using polyvinyl alcohol, 

International Journal of Ambient Energy, 42(2), 220–226.  

Manvith Kumar Reddy C., Ramesh B., Macrin D., 2020, Effect of crystalline admixtures, polymers and fibers on 

self healing concrete - a review. Materials Today: Proceedings, 33, 763–770.  

Mazela B., Perdoch W., Peplinska B., Zielinski M., 2020, Influence of chemical pre-treatments and 

ultrasonication on the dimensions and appearance of cellulose fibers, Materials, 13, 5274. 

Mullem T. V., Gruyaert E., Caspeele R., Belie N. De., 2020, First large scale application with self-healing 

concrete in belgium: Analysis of the laboratory control tests, Materials, 13(4), 997. 

Tan L., Reeksting B., Ferrandiz-Mas V., Heath A., Gebhard S., Paine K., 2020, Effect of carbonation on bacteria-

based self-healing of cementitious composites, Construction and Building Materials, 257, 119501. 

Tan N. P. B., Keung L. H., Choi W. H. Lam W. C., Leung, H. N., 2016, Silica-based self-healing microcapsules 

for self-repair in concrete, Journal of Applied Polymer Science, 133(12), 1–12.  

Wang Y., Lin Z., Tang C., Hao W., 2021, Influencing factors on the healing performance of microcapsule self-

healing concrete, Materials, 14(15), 4139. 
 

 

672


	250Damasco.pdf
	Synthesis of Nanocellulose from Durian Rinds for the Preparation of a Self-healing Smart Concrete with Augmented Mechanical Properties