Biofiber is used in the polymer based composite as a renewable resource due to its positive environmental benefits, biodegradable properties, low cost and high toughness. Biocomposite was fabricated using oil palm empty fruit bunch (EFB) as filler in phenolated EFB (PEFB) matrix. Phenolated EFB (PEFB) obtained from liquefaction of EFB in phenol was used as a biopolymer to replace novolak phenolic resin which is commonly used in composite materials. Sulfuric acid was used as a catalyst in the liquefaction reaction. The effect of thermal aging and blending ratio of PEFB matrix and EFB fibers on the mechanical properties of composites has been studied. The flexural data before and after thermal aging revealed the optimum amount of EFB filler is 50% . The result showed better compatibility between EFB and PEFB when compared with EFB and commercial novolak resin.
Cellulose carbamate (CC) was synthesized via hydrothermal process and mixed with graphene oxide (GO) to form a homogeneous cellulose matrix nanocomposite films. The properties of CC/GO nanocomposite films fabricated using simple solution-mixing method with different GO loadings were studied. Transmission electron microscope analysis showed the exfoliation of self-synthesized GO nanosheets within the CC matrix. X-ray diffraction results confirmed the crystalline structure of CC/GO films as the CC/GO mass ratio increased from 100/0 to 100/4. The mechanical properties of CC/GO film were significantly improved as compared to neat CC film. From thermogravimetric analysis result, the introduction of GO enhanced the thermal stability and carbon yields. The 3D homogeneous porous structures of the CC/GO films were observed under Field emission scanning electron microscope. These improvements in nanocomposite film properties could be confirmed by Fourier transform infrared spectroscopy due to the strong and good interactions between CC and GO.
In this study, cellulose nanocrystals (CNC) were produced using acid hydrolysis method. Kenaf core was pretreated with 4
wt. % sodium hydroxide (NaOH), followed by bleaching using 1.7 wt. % sodium chlorite (NaClO2
) in acetate buffer. The
bleached fiber was acid hydrolyzed for 45 and 55 min using 64 wt. % sulfuric acid (H2
SO4
). The size distribution of the
CNC segregated via differential centrifugation with different speed was also investigated. The CNC suspension obtained
was centrifuged at 3000, 6000, 9000 and 12000 rpm. The resultant CNC suspension collected was characterized using
Fourier transform infrared (FTIR) analysis, X-ray diffraction (XRD) and transmission electron microscopy (TEM). FTIR
results showed the progressive removal of non-cellulosic constituents for each subsequent treatment. It also showed that
the CNC produced after hydrolysing for 55 min has the highest degree of crystallinity (81.15%). CNC produced from acid
hydrolysis process of 45 min have lengths between 50 and 270 nm while CNC produced from acid hydrolysis process of
55 min have length around 40 to 370 nm.
Proses pencecairan lignin soda telah dilakukan dengan menggunakan fenol dengan nisbah 1:3. Proses dilakukan selama 90 minit pada suhu 130oC dalam keadaan refluk. Hasil pencecairan iaitu pemfenolan lignin (PL) telah dianalisis dengan Spektrometer Inframerah Transformasi Fourier (FTIR), reometer dan analisis termogravimetri (TGA). Sampel yang disintesis dengan menggunakan asid hidroklorik sebagai mangkin memberikan keputusan yang terbaik. Analisis FTIR menunjukkan kehadiran kumpulan berfungsi yang signifikan seperti gelang aromatik, alkohol dan karbonil. Kesemua sampel PL mematuhi persamaan Arhenius dan bersifat pseudo-plastik. Peratus kehilangan berat sampel dan kadar penguraian sampel PL dipengaruhi oleh jenis mangkin yang digunakan. Sampel PL yang disintesis dikelaskan sebagai biopolimer resin fenolik.
One of the most prolific plants utilized in various applications is mangosteen (Garcinia mangostana L.). Rich in potent bioactive compounds, such as xanthones, mangosteen is known to possess pharmacologically important anti-inflammatory and anti-tumor properties. However, most previous reviews have only discussed the application of mangosteen in medicinal areas, yet more recent studies have diverged and valorized its usage in other scientific fields. In this review, the utilization of this exotic fruit in postharvest biology (phytohormone roles, metabolite profiling, bioactive compounds, isolation method optimization, chemical contaminant identification, and management of pests and fruit disorders), food science (food products, animal feed supplementation, and food shelf-life determination), and engineering fields (fabric and solar cell dyes, carbon dots, activated carbon, and biomedical advanced materials) is presented in detail. Research papers published from 2016 onward were selected and reviewed to show the recent research trends in these areas. In conclusion, mangosteen has been utilized for various purposes, ranging from usage in industrially important products to applications in advanced technologies and biomedical innovation.
Cellulose was extracted from kenaf core pulp (KCP) by a series of bleaching processes (D) and alkali treatment (E) in the sequence of (DEED) and pretreated with acid hydrolysis in room temperature for 6 hours. The pretreated and non-treated cellulose were dissolved in lithium hydroxide/urea (LiOH/urea) and subsequently used to produce cellulose membrane cross linked with various percentages of glyoxal from 2.5 to 20%. The effects of acid hydrolysis pretreatment on solubility, crystallinity and morphology were investigated. The acid hydrolysis pretreatment leads to higher solubility of the cellulose solution. The formation of cellulose II and crystallinity index of the cellulose membrane were examined by X-ray diffraction (XRD). Cellulose membrane without acid hydrolysis pretreatment cross linked with higher percentage of glyoxal has higher tensile strength compared with the treated cellulose.
In this study oil palm empty fruit bunches (EFB) fibres was used to synthesize biophenolic resin (BPR) at a different
formaldehyde/liquefied empty fruit bunches (F/LEFB) molar ratio which is 1.0, 1.5 and 2.0. The higher molar ratio of F/
LEFB used has resulted in an increased of viscosity and solid content of BPR resin. The first decomposition of BPR resin
occured around 86 to 130°C due to the evaporation of low molecular weight substance which were water, free phenol
and formaldehyde. Glass fibre reinforced biophenolic composite (BPC) and glass fibre reinforced biophenolic elastomer
composite (BPEC) was successfully fabricated using BPR resin. The impact strength and flexural strain of BPEC were
higher than that of BPC. The impact strength of BPEC 1.5 was the highest at 47.71 kJm-2. However, the flexural strength
of BPEC was lower compared with BPC, which the highest flexural strength was obtained by BPC 1.0 at 65.18 MPa. The
cross-sectional image from scanning electron microscope (SEM) of BPEC and BPC confirmed the presence of epoxidized
natural rubber (ENR) improved the compatibility between glass fibre and BPR resin.
In this study, magnetic cellulose membranes (MCM) have been prepared by using cotton linter as cellulose source and NaOH/urea as cellulose solvent at different magnetite content. Cellulose was dissolved in pre-cooled NaOH/urea solvent at -13°C to form cellulose solution. The cellulose solution then was mix with magnetite (Fe3O4) nanoparticles synthesized via co-precipitation method of Fe2+ and Fe3+ in the presence of sodium hydroxide (NaOH) to form MCM. The MCMs formed at different percentage of Fe3O4 i.e., 10, 20 and 30%. Analysis from vibrating sample magnetometer (VSM) shows that the saturation magnetization of the MCM increase as the percentages of Fe3O4 nanoparticles increased. However, the addition of Fe3O4 nanoparticles in the regenerated cellulose membrane has decreased the crystallinity index of MCM. The surface morphology of the MCM showed that the Fe3O4 nanoparticles were dispersed in the pore of the membrane. Tensile test showed decreasing in the tensile strength of the cellulose membrane with the addition of Fe3O4 nanoparticle.
Oil palm is the major crop grown and cultivated in various Asian countries such as Malaysia, Indonesia and Thailand.
The core of oil palm trunk (COPT) consists of high sugar content, hence suitable for synthesis of fine chemicals and
biofuels. Increase of sugar content was reported previously during prolonged COPT storage. However, until now, there
has been no report on protein profiles during storage. Therefore, in this study, protein expression of the COPT during the
storage period of one to six weeks was investigated using sodium dodecyl sulphate polyacrylamide gel electrophoresis
(SDS-PAGE) coupled with optical density quantification and multivariate analyses for measuring differentially expressed
proteins. Accordingly, protein bands were subjected to tryptic digestion followed by tandem mass spectrometry (nanoLCMS/MS)
protein identification. The results from SDS-PAGE showed consistent protein bands appearing across the biological
replicates ranging from 10.455 to 202.92 kDa molecular weight (MW) regions. The findings from the principal component
analysis (PCA) plot illustrated the separation pattern of the proteins at weeks 4 and 5 of storage, which was influenced
mainly by the molecular weights of 14.283, 25.543, 29.757, 30.549, 31.511, 34.585 and 84.395 kDa, respectively. The
majority of these proteins are identified as those involved in stress- and defense-related, disease resistance, as well
as gene/protein expression processes. Indeed, these proteins were mostly upregulated during the later storage period
suggesting that long-term storage may influence the molecular regulation of COPT sap.
Membran selulosa terjana semula (MS) daripada pulpa teras kenaf telah berjaya dihasilkan menggunakan kaedah pra penyejukan dan digumpal menggunakan larutan asid sulfurik. MS disediakan daripada pelarutan selulosa kenaf dalam larutan akues NaOH/urea dan larutan selulosa seterusnya digumpal dengan H2SO4 pada kepekatan 5-12 peratus berat (% bt.) selama 1-10 min. Pengaruh kepekatan penggumpal H2SO4 dan masa penggumpalan ke atas struktur, saiz liang, sifat mekanik dan ketelusan cahaya MS telah dikaji menggunakan pembelauan sinar-X (XRD), imbasan mikroskop elektron tekanan boleh ubah (VPSEM), penguji regangan dan spektrofotometer ultra-violet sinar tampak (UV-vis). Keputusan VPSEM menunjukkan perubahan saiz liang membran bergantung kepada kepekatan larutan penggumpal H2SO4, manakala masa penggumpalan tidak mempengaruhi saiz liang membran. Membran yang direndam dengan larutan penggumpal pada kepekatan 10 % bt. dan masa pembekuan yang sederhana iaitu 5 min menunjukkan sifat mekanik yang lebih baik dengan nilai kekuatan regangan masing-masing 41.9 dan 43.5 MPa. Oleh itu, kajian ini dapat memberikan maklumat mengenai penyediaan MS dengan pelbagai saiz liang dan sifat mekanik dengan pengubahsuaian kepekatan dan masa penggumpalan.
Bio-novolac fibre made from phenol-formaldehyde derived oil palm empty fruit bunch (EFB) was produced using electrospinning method. The bio-novolac phenol-formaldehyde was prepared via liquefaction and resinification at two different molar ratios of formaldehyde to liquefied EFB (LEFB) (F:LEFB = 0.5:1 and 0.8:1). Electrospinning was applied to the bio-novolac phenol-formaldehyde (BPF) in order to form smooth and thin as-spun fibre. The BPF was electrospun at 15 kV and 15 cm distance between needle and collector at a flow rate of 0.5 mL/h. At lower molecular weight of BPF resin, beads formation was observed. The addition of poly(vinyl) butyral (Mw = 175,000 - 250,000) has improved the fibre formation with lesser beads hence produced more fibre. Polymer solution with higher molecular weight produced better quality fibre.
Chemical and thermal properties of pure lignin are depending on the plant origin, extraction method and type of
lignocellulosic. In this study, lignin from oil palm empty fruit bunch (EFB) and kenaf core were recovered from soda black
liquor by two steps of acid precipitation with hydrochloric acid and followed by soxhlet with n-hexane. The XRD analysis
of purified EFB lignin (EAL) and purified kenaf core lignin (KAL) exhibited amorphous properties, similar to the standard
alkali lignin (SAL). The FTIR and Raman spectra showed that all samples consist of HGS unit. In FTIR, the syringyl unit is
assigned at (1125 cm-1), (1327 and 1121 cm-1) and (1326and 1117 cm-1) meanwhile the guaicyl unit is assigned at (1263,
1212 and 1028 cm-1), (1271, 1217 and 1028 cm-1) and (1270, 1211 and 1030 cm-1) for SAL, EAL and KAL, respectively.
The peak around 1160 cm-1 represents C-O stretching of conjugated ester group present in HGS lignin. As for Raman, the
HGS unit exists in the range of 1100-1400 cm-1. Among the purified samples, the TGA result showed that KAL has a better
thermal stability with the residue of 36.49% and higher Tg value which is 152.69°C.
Bleached kenaf core pulps (BKC) were hydrolyzed in H2SO4 (0.5M) at different time (0min to 90min) at room temperature. After the hydrolysis process, the viscosity average molecular weight (Mŋ) for BKC sample has reduced from 14.5×10(4) to 2.55×10(4). The hydrolyzed BKC was then dissolved in NaOH:urea:water and in LiOH:urea:water mixed solvent at the ratio of 7:12:81 and 4.6:15:80.4, respectively. The increased in hydrolysis time has decreased Mŋ of cellulose leading to easy dissolution process. Higher porosity and transparency with lower crystallinity index (CrI) of regenerated membrane produced can be achieved as the Mŋ reduced. The properties of membrane were observed through FESEM, UV-vis spectrophotometer and XRD. This study has proven that acid hydrolysis has reduced the Mŋ of cellulose, thus, enhanced the properties of regenerated membrane produced with assisted by alkaline/urea system.
Dissolved oil palm empty fruit bunch (EFB) cellulose in NaOH/urea solvent was mixed with sodium carboxymethylcellulose (NaCMC) to form a green regenerated superabsorbent hydrogel. The effect of concentration of epichlorohydrin (ECH) as the crosslinker on the formation, physical, and chemical properties of hydrogel was studied. Rapid formation and higher gel content of hydrogel were observed at 10% concentration of ECH. The superabsorbent hydrogel was successfully fabricated in this study with the swelling ability >100,000%. Hydrogel with higher concentration of ECH showed opposite trend by having higher superabsorbent property than that of lower concentration. The covalent bond of COC was observed with Attenuated total reflectance fourier transform infrared (ATR-FT-IR) spectroscopy to confirm the occurrence of crosslinking. The physical and chemical properties of hydrogel were affected by swelling phenomenon. Hydrogel with higher degree of swelling exhibited lower moisture retention and higher transparency. Moreover, the weight of the superabsorbent hydrogel increased with the decrement of pH value of external media (distilled water). This study provided substantial information on the effect of different percentage of ECH as crosslinker on hydrogel basic properties. Furthermore, this study affords correlation of many essential driving forces that affected hydrogel superabsorbent property.
Bemisia tabaci (Gennadius) whitefly (BtWf) is an invasive pest that has already spread worldwide and caused major crop losses. Numerous strategies have been implemented to control their infestation, including the use of insecticides. However, prolonged insecticide exposures have evolved BtWf to resist these chemicals. Such resistance mechanism is known to be regulated at the molecular level and systems biology omics approaches could shed some light on understanding this regulation wholistically. In this review, we discuss the use of various omics techniques (genomics, transcriptomics, proteomics, and metabolomics) to unravel the mechanism of insecticide resistance in BtWf. We summarize key genes, enzymes, and metabolic regulation that are associated with the resistance mechanism and review their impact on BtWf resistance. Evidently, key enzymes involved in the detoxification system such as cytochrome P450 (CYP), glutathione S-transferases (GST), carboxylesterases (COE), UDP-glucuronosyltransferases (UGT), and ATP binding cassette transporters (ABC) family played key roles in the resistance. These genes/proteins can then serve as the foundation for other targeted techniques, such as gene silencing techniques using RNA interference and CRISPR. In the future, such techniques will be useful to knock down detoxifying genes and crucial neutralizing enzymes involved in the resistance mechanism, which could lead to solutions for coping against BtWf infestation.
Development of polyurethane foam (PUF) containing bio-based components is a complex process that requires extensive studies. This work reports on the production of rigid PUFs from polyol obtained via liquefaction of oil palm empty fruit bunch (EFB) biomass with different isocyanate (NCO) indexes. The effect of the NCO index on the physical, chemical and compressive properties of the liquefied EFB-based PUF (EFBPUF) was evaluated. The EFBPUFs showed a unique set of properties at each NCO index. Foaming properties had affected the apparent density and cellular morphology of the EFBPUFs. Increasing NCO index had increased the crosslink density and dimensional stability of the EFBPUFs via formation of isocyanurates, which had also increased their thermal stability. Combination of both foaming properties and crosslink density of the EFBPUFs had influenced their respective compressive properties. The EFBPUF produced at the NCO index of 120 showed the optimum compressive strength and released the least toxic hydrogen cyanide (HCN) gas under thermal degradation. The normalized compressive strength of the EFBPUF at the NCO index of 120 is also comparable with the strength of the PUF produced using petrochemical polyol.