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Effective mitigation of single-component and mixed textile dyes from aqueous media using recyclable graphene-based nanocomposite

Tran TV, Vo DN, Nguyen DTC, Ching YC, Nguyen NT, Nguyen QT

Environ Sci Pollut Res Int, 2022 Jan 11.
PMID: 35013974 DOI: 10.1007/s11356-022-18570-y

The present study reported the synthesis and utilization of a graphene-based hybrid nanocomposite (MnFe2O4/G) to mitigate several synthetic dyes, including methylene blue, malachite green, crystal violet, and Rhodamine B. This adsorbent was structurally analyzed by several physicochemical techniques such as X-ray diffraction, Fourier-transform infrared spectroscopy, scanning electron microscopy, Raman spectroscopy, N2 adsorption-desorption isotherm measurement, point of zero charge, and Boehm titrations. BET surface area of MnFe2O4/G was measured at 382.98 m2/g, which was substantially higher than that of MnFe2O4. MnFe2O4/G possessed diverse surface chemistry properties with the presence of many functional groups such as carboxylic acid, phenolic, lactone, and basic groups. MnFe2O4/G was used to remove synthetic dyes in the aqueous media. The effect of many factors, e.g., concentration (5-50 mg/L), pH (4-10), dose (5-20 mg), and temperature (25-45 °C) on adsorption performance of MnFe2O4/G was conducted. Kinetic, isotherm, intraparticle, and thermodynamic models were adopted for investigating adsorption phenomenon of dyes on MnFe2O4/G. The maximum adsorption capacity of dyes over MnFe2O4/G was found as Rhodamine B (67.8 mg/g) < crystal violet (81.3 mg/g) < methylene blue (137.7 mg/g) < malachite green (394.5 mg/g). Some tests were performed to remove mixed dyes, and mixed dyes in the presence of antibiotics with total efficiencies of 65.8-87.9% after 120 min. Moreover, the major role of π-π stacking interaction was clarified to gain insight into the adsorption mechanism. MnFe2O4/G could recycle up to 4 cycles, which may be beneficial for further practical water treatment.
Effect of TEMPO-oxidization and rapid cooling on thermo-structural properties of nanocellulose

Mhd Haniffa MAC, Ching YC, Chuah CH, Yong Ching K, Nazri N, Abdullah LC, et al.

Carbohydr Polym, 2017 Oct 01;173:91-99.
PMID: 28732923 DOI: 10.1016/j.carbpol.2017.05.084

Recently, surface functionality and thermal property of the green nanomaterials have received wide attention in numerous applications. In this study, microcrystalline cellulose (MCC) was used to prepare the nanocrystalline celluloses (NCCs) using acid hydrolysis method. The NCCs was treated with TEMPO [(2,2,6,6-tetramethylpiperidin-1-yl)oxy radical]-oxidation to prepare TEMPO-oxidized NCCs. Cellulose nanofibrils (CNFs) also prepared from MCC using TEMPO-oxidation. The effects of rapid cooling and chemical treatments on the thermo-structural property studies of the prepared nanocelluloses were investigated through FTIR, thermogravimetric analysis-derivative thermogravimetric (TGA-DTG), and XRD. A posteriori knowledge of the FTIR and TGA-DTG analysis revealed that the rapid cooling treatment enhanced the hydrogen bond energy and thermal stability of the TEMPO-oxidized NCC compared to other nanocelluloses. XRD analysis exhibits the effect of rapid cooling on pseudo 2Ihelical conformation. This was the first investigation performed on the effect of rapid cooling on structural properties of the nanocellulose.
Influence of a nonionic surfactant on curcumin delivery of nanocellulose reinforced chitosan hydrogel

Sampath Udeni Gunathilake TM, Ching YC, Chuah CH, Illias HA, Ching KY, Singh R, et al.

Int J Biol Macromol, 2018 Oct 15;118(Pt A):1055-1064.
PMID: 30001596 DOI: 10.1016/j.ijbiomac.2018.06.147

Nanocellulose reinforced chitosan hydrogel was synthesized using chemical crosslinking method for the delivery of curcumin which is a poorly water-soluble drug. Curcumin extracted from the dried rhizomes of Curcuma longa was incorporated to the hydrogel via in situ loading method. A nonionic surfactant (Tween 20) was incorporated into the hydrogel to improve the solubility of curcumin. After the gas foaming process, hydrogel showed large interconnected pore structures. The release studies in gastric medium showed that the cumulative release of curcumin increased from 0.21% ± 0.02% to 54.85% ± 0.77% with the increasing of Tween 20 concentration from 0% to 30% (w/v) after 7.5 h. However, the entrapment efficiency percentage decreased with the addition of Tween 20. The gas foamed hydrogel showed higher initial burst release within the first 120 min compared to hydrogel formed at atmospheric condition. The solubility of curcumin would increase to 3.014 ± 0.041 mg/mL when the Tween 20 concentration increased to 3.2% (w/v) in simulated gastric medium. UV-visible spectra revealed that the drug retained its chemical activity after in vitro release. From these findings, it is believed that the nonionic surfactant incorporated chitosan/nanocellulose hydrogel can provide a platform to overcome current problems associated with curcumin delivery.
Electro-Stimulated Release of Poorly Water-Soluble Drug from Poly(Lactic Acid)/Carboxymethyl Cellulose/ZnO Nanocomposite Film

Gunathilake TMSU, Ching YC, Chuah CH, Hai ND, Nai-Shang L

Pharm Res, 2020 Aug 30;37(9):178.
PMID: 32864721 DOI: 10.1007/s11095-020-02910-z

PURPOSE: Among various types of external stimuli-responsive DDS, electric-responsive DDS are more promising carriers as they exploit less complex, easily miniaturized electric signal generators and the possibility of fine-tuning the electric signals. This study investigates the use of intrinsically biocompatible biopolymers in electro-simulative drug delivery to enhance the release of poorly-soluble/non-ionic drug.
METHODS: CMC/PLA/ZnO/CUR nanocomposite films were prepared by the dispersion of CMC and ZnO NPs in solubilized PLA/curcumin medium, followed by solvent casting step. Curcumin is poorly water-soluble and used as the model drug in this study. The films with different contents of CMC, PLA and ZnO NPs were characterized using FTIR, impedance spectroscopy, tensile testing and FESEM imaging. The in vitro drug release of the films was carried out in deionized water under DC electric field of 4.5 V.
RESULTS: The ionic conductivity of the films increased with increasing the CMC concentration of the film. The addition of a small amount of ZnO NPs (2%) successfully restored the tensile properties of the film. In response to the application of the electric field, the composite films released drug with a near-linear profile. There was no noticeable amount of passive diffusion of the drug from the film with the absence of the electric field.
CONCLUSION: The outcome of this study enabled the design of an electric-responsive nanocomposite platform for the delivery of poorly water-soluble/non-ionic drugs. Graphical abstract.
Multivariate Analysis on Orofacial Odontogenic Infection in Northern Peninsular Malaysia

Ching YC, Poh NM, Ee KS, Feng LX, Mun YK, Mei TM

J Oral Maxillofac Surg, 2021 Nov 13.
PMID: 34863695 DOI: 10.1016/j.joms.2021.11.007

PURPOSE: This regional 2-center study was designed 1) to analyze the clinical features of all patients with odontogenic orofacial infection as per type of visit, 2) to analyze the clinical features of diabetic patients compared with nondiabetic patients, and 3) to identify potential variables that may associate with long length of stay (LOS) of patients admitted for orofacial odontogenic infection in Northern Peninsular Malaysia.
PATIENTS AND METHODS: All adult patients with orofacial odontogenic infections who attended the Oral and Maxillofacial Department of Hospital Raja Permaisuri Bainun and Hospital Sultan Abdul Halim from March 2015 to February 2019 were included. Data on patients' demography, medical history, smoking status, clinical presentation, and LOS were collected. Multivariate logistic regression analysis was performed using the dichotomous dependent variable, namely, short LOS (LOS <5 days) and long LOS (LOS ≥5 days).
RESULTS: A total of 355 patients were reported with the mean age of 39.93 ± 15.95 years old. Multivariate analysis revealed that diabetes (adjusted odds ratio = 4.387, 95% confidence interval = 1.453 to 13.241, P value = .009) and multiple space involvement (adjusted odds ratio = 4.859, 95% confidence interval = 1.280, 18.454, P value = .020) were responsible for long LOS.
CONCLUSIONS: Judicious treatment is recommended when treating patients of such infection that involved multiple spaces with underlying diabetes mellitus.
Fulltext Preparation and Characterization of Starch/Empty Fruit Bunch-Based Bioplastic Composites Reinforced with Epoxidized Oils

Yang J, Ching YC, Chuah CH, Liou NS

Polymers (Basel), 2020 Dec 29;13(1).
PMID: 33383626 DOI: 10.3390/polym13010094

This study examined the development of starch/oil palm empty fruit bunch-based bioplastic composites reinforced with either epoxidized palm oil (EPO) or epoxidized soybean oil (ESO), at various concentrations, in order to improve the mechanical and water-resistance properties of the bio-composites. The SEM micrographs showed that low content (0.75 wt%) of epoxidized oils (EOs), especially ESO, improved the compatibility of the composites, while high content (3 wt%) of EO induced many voids. The melting temperature of the composites was increased by the incorporation of both EOs. Thermal stability of the bioplastics was increased by the introduction of ESO. Low contents of EO led to a huge enhancement of tensile strength, while higher contents of EO showed a negative effect, due to the phase separation. The tensile strength increased from 0.83 MPa of the control sample to 3.92 and 5.42 MPa for the composites with 1.5 wt% EPO and 0.75 wt% ESO, respectively. EOs reduced the composites' water uptake and solubility but increased the water vapor permeability. Overall, the reinforcing effect of ESO was better than EPO. These results suggested that both EOs can be utilized as modifiers to prepare starch/empty-fruit-bunch-based bioplastic composites with enhanced properties.
Fulltext Synthesis, Characterization and the Solvent Effects on Interfacial Phenomena of Jatropha Curcas Oil Based Non-Isocyanate Polyurethane

Haniffa MACM, Ching YC, Chuah CH, Kuan YC, Liu DS, Liou NS

Polymers (Basel), 2017 May 01;9(5).
PMID: 30970841 DOI: 10.3390/polym9050162

Non-isocyanate polyurethane (NIPU) was prepared from Jatropha curcas oil (JCO) and its alkyd resin via curing with different diamines. The isocyanate-free approach is a green chemistry route, wherein carbon dioxide conversion plays a major role in NIPU preparation. Catalytic carbon dioxide fixation can be achieved through carbonation of epoxidized derivatives of JCO. In this study, 1,3-diaminopropane (DM) and isophorone diamine (IPDA) were used as curing agents separately. Cyclic carbonate conversion was catalyzed by tetrabutylammonium bromide. After epoxy conversion, carbonated JCO (CJCO) and carbonated alkyd resin (CC-AR) with carbonate contents of 24.9 and 20.2 wt %, respectively, were obtained. The molecular weight of CJCO and CC-AR were determined by gel permeation chromatography. JCO carbonates were cured with different amine contents. CJCO was blended with different weight ratios of CC-AR to improve its characteristics. The cured NIPU film was characterized by spectroscopic techniques, differential scanning calorimetry, and a universal testing machine. Field emission scanning electron microscopy was used to analyze the morphology of the NIPU film before and after solvent treatment. The solvent effects on the NIPU film interfacial surface were investigated with water, 30% ethanol, methyl ethyl ketone, 10% HCl, 10% NaCl, and 5% NaOH. NIPU based on CCJO and CC-AR (ratio of 1:3) with IPDA crosslink exhibits high glass transition temperature (44 °C), better solvent and chemical resistance, and Young's modulus (680 MPa) compared with the blend crosslinked with DM. Thus, this study showed that the presence of CC-AR in CJCO-based NIPU can improve the thermomechanical and chemical resistance performance of the NIPU film via a green technology approach.
Fulltext Preparation and Characterization of Polyvinyl Alcohol-Chitosan Composite Films Reinforced with Cellulose Nanofiber

Choo K, Ching YC, Chuah CH, Julai S, Liou NS

Materials (Basel), 2016 Jul 29;9(8).
PMID: 28773763 DOI: 10.3390/ma9080644

In this study microcrystalline cellulose (MCC) was oxidized by 2,2,6,6-tetramethylpiperidine-1-oxyl radical (TEMPO)-mediated oxidation. The treated cellulose slurry was mechanically homogenized to form a transparent dispersion which consisted of individual cellulose nanofibers with uniform widths of 3-4 nm. Bio-nanocomposite films were then prepared from a polyvinyl alcohol (PVA)-chitosan (CS) polymeric blend with different TEMPO-oxidized cellulose nanofiber (TOCN) contents (0, 0.5, 1.0 and 1.5 wt %) via the solution casting method. The characterizations of pure PVA/CS and PVA/CS/TOCN films were performed in terms of field emission scanning electron microscopy (FESEM), tensile tests, thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FTIR), and X-ray diffraction (XRD). The results from FESEM analysis justified that low loading levels of TOCNs were dispersed uniformly and homogeneously in the PVA-CS blend matrix. The tensile strength and thermal stability of the films were increased with the increased loading levels of TOCNs to a maximum level. The thermal study indicated a slight improvement of the thermal stability upon the reinforcement of TOCNs. As evidenced by the FTIR and XRD, PVA and CS were considered miscible and compatible owing to hydrogen bonding interaction. These analyses also revealed the good dispersion of TOCNs within the PVA/CS polymer matrix. The improved properties due to the reinforcement of TOCNs can be highly beneficial in numerous applications.
Recent advances in celluloses and their hybrids for stimuli-responsive drug delivery

Sampath Udeni Gunathilake TM, Ching YC, Chuah CH, Rahman NA, Liou NS

Int J Biol Macromol, 2020 May 07;158:670-688.
PMID: 32389655 DOI: 10.1016/j.ijbiomac.2020.05.010

The limitations of existing drug delivery systems (DDS) such as non-specific bio-distribution and poor selectivity have led to the exploration of a variety of carrier platforms to facilitate highly desirable and efficient drug delivery. Stimuli-responsive DDS are one of the most versatile and innovative approach to steer the compounds to the intended sites by exploiting their responsiveness to a range of various triggers. Preparation of stimuli-responsive DDS using celluloses and their derivatives offer a remarkable advantage over conventional polymer materials. In this review, we highlight on state-of-art progress in developing cellulose/cellulose hybrid stimuli-responsive DDS, which covers the preparation techniques, physicochemical properties, basic principles and, mechanisms of stimuli effect on drug release from various types of cellulose based carriers, through recent innovative investigations. Attention has been paid to endogenous stimuli (pH, temperature, redox gradient and ionic-strength) responsive DDS and exogenous stimuli (light, magnetic field and electric field) responsive DDS, where the cellulose-based materials have been extensively employed. Furthermore, the current challenges and future prospects of these DDS are also discussed at the end.
Occurrence and exposure risk assessment of organic micropollutants in indoor dust from Malaysia

Yang J, Ching YC, Kadokami K

Chemosphere, 2022 Jan;287(Pt 3):132340.
PMID: 34826953 DOI: 10.1016/j.chemosphere.2021.132340

Indoor dust is an important source of human exposure to hazardous organic micropollutants (OMPs) because humans spend about 90 % of their time in the indoor environments. This study initially analyzed the concentrations and compositions of OMPs in the dust of different indoor environments from Kuala Lumpur, Malaysia. A total of 57 OMPs were detected and assigned to 7 chemical classes in this study. The total concentration of OMPs ranged from 5980 to 183,000 ng/g, with the median concentration of 46,400 ng/g. Personal care products, organophosphate esters, and pesticides were the dominant groups, with their median concentrations at 12,000, 10,000, and 5940 ng/g, respectively. The concentrations and compositions of influential OMPs varied in different microenvironments, suggesting different sources and usage patterns in the house. Then, the noncarcinogenic and carcinogenic risks of exposure to these substances for diverse age groups were assessed based on the median concentration. Cumulative noncarcinogenic risks of these OMPs via ingestion pathway were estimated to be negligible (1.41 × 10-4 - 1.87 × 10-3). The carcinogenic risks of these OMPs were higher than 10-6 (1.63 × 10-6 - 6.17 × 10-6) and should be noted. Theobromine accounted for more than 89 % of the cumulative cancer risk, implying that the carcinogenic risk of theobromine needs further monitoring in the future. Toddler was the most affected group for cancer risk among all the age groups, regardless of the microenvironments. These findings from this study may provide a benchmark for future efforts to ensure the safety of indoor dust for the local residents.
Fulltext Comparison of biogenic silver nanoparticles formed by Momordica charantia and Psidium guajava leaf extract and antifungal evaluation

Nguyen DH, Vo TNN, Nguyen NT, Ching YC, Hoang Thi TT

PLoS One, 2020;15(9):e0239360.
PMID: 32960911 DOI: 10.1371/journal.pone.0239360

Exploiting plant extracts to form metallic nanoparticles has been becoming the promising alternative routes of chemical and physical methods owing to environmentally friendly and abundantly renewable resources. In this study, Momordica charantia and Psidium guajava leaf extract (MC.broth and PG.broth) are exploited to fabricate two kinds of biogenic silver nanoparticles (MC.AgNPs and PG.AgNPs). Phytoconstituent screening is performed to identify the categories of natural compounds in MC.broth and PG.broth. Both extracts contain wealthy polyphenols which play a role of reducing agent to turn silver (I) ions into silver nuclei. Trace alkaloids, rich saponins and other oxygen-containing compounds creating the organic corona surrounding nanoparticles act as stabilizing agents. MC.AgNPs and PG.AgNPs are characterized by UV-vis and FTIR spectrophotometry, EDS and TEM techniques. FTIR spectra indicate the presence of O-H, C = O, C-O-C and C = C groups on the surface of silver nanoparticles which is corresponded with three elements of C, O and Ag found in EDS analysis. TEM micrographs show the spherical morphology of MC.AgNPs and PG.AgNPs. MC.AgNPs were 17.0 nm distributed in narrow range of 5-29 nm, while the average size of PG.AgNPs were 25.7 nm in the range of 5-53 nm. Further, MC.AgNPs and PG.AgNPs exhibit their effectively inhibitory ability against A. niger, A. flavus and F. oxysporum as dose-dependence. Altogether, MC.AgNPs and PG.AgNPs will have much potential in scaled up production and become the promising fungicides for agricultural applications.
Fulltext Green Silver Nanoparticles Formed by Phyllanthus urinaria, Pouzolzia zeylanica, and Scoparia dulcis Leaf Extracts and the Antifungal Activity

Nguyen DH, Lee JS, Park KD, Ching YC, Nguyen XT, Phan VHG, et al.

Nanomaterials (Basel), 2020 Mar 17;10(3).
PMID: 32192177 DOI: 10.3390/nano10030542

Phytoconstituents presenting in herbal plant broths are the biocompatible, regenerative, and cost-effective sources that can be utilized for green synthesis of silver nanoparticles. Different plant extracts can form nanoparticles with specific sizes, shapes, and properties. In the study, we prepared silver nanoparticles (P.uri.AgNPs, P.zey.AgNPs, and S.dul.AgNPs) based on three kinds of leaf extracts (Phyllanthus urinaria, Pouzolzia zeylanica, and Scoparia dulcis, respectively) and demonstrated the antifungal capacity. The silver nanoparticles were simply formed by adding silver nitrate to leaf extracts without using any reducing agents or stabilizers. Formation and physicochemical properties of these silver nanoparticles were characterized by UV-vis, Fourier transforms infrared spectroscopy, scanning electron microscope, transmission electron microscope, and energy dispersive X-ray spectroscopy. P.uri.AgNPs were 28.3 nm and spherical. P.zey.AgNPs were 26.7 nm with hexagon or triangle morphologies. Spherical S.dul.AgNPs were formed and they were relatively smaller than others. P.uri.AgNPs, P.zey.AgNPs and S.dul.AgNPs exhibited the antifungal ability effective against Aspergillus niger, Aspergillus flavus, and Fusarium oxysporum, demonstrating their potentials as fungicides in the biomedical and agricultural applications.
Fulltext Optimization of Mechanical Properties for Polyoxymethylene/Glass Fiber/Polytetrafluoroethylene Composites Using Response Surface Methodology

Kunnan Singh JS, Ching YC, Abdullah LC, Ching KY, Razali S, Gan SN

Polymers (Basel), 2018 Mar 20;10(3).
PMID: 30966373 DOI: 10.3390/polym10030338

This paper investigated the effects of polytetrafluoroethylene (PTFE) micro-particles on mechanical properties of polyoxymethylene (POM) composites. Since PTFE is immiscible with most polymers, the surface was etched using sodium naphthalene salt in tetrahydrofuran to increase its surface energy. The effects of two variables, namely PTFE content and PTFE etch time, on the mechanical properties of the composite were studied. Experiments were designed in accordance to response surface methodology (RSM) using central composite design (CCD). Samples were prepared with different compositions of PTFE (1.7, 4.0, 9.5, 15.0, or 17.3 wt %) at different PTFE etch times (2.9, 5.0, 10.0, 15.0, or 17.1 min). Four mechanical properties of the POM/GF/PTFE composites, that is, strength, stiffness, toughness, and hardness, were characterized as a function of two studied variables. The dependency of these mechanical properties on the PTFE etch conditions was analyzed using analysis of variance (ANOVA). Overall desirability, D global index, was computed based on the combination of these mechanical properties for POM/GF/PTFE composites. The D global index was found to be 87.5%, when PTFE content and PTFE etch time were 6.5% and 10 min, respectively. Good correlation between experimental and RSM models was obtained using normal probability plots.
Fulltext Effects of PTFE Micro-Particles on the Fiber-Matrix Interface of Polyoxymethylene/Glass Fiber/Polytetrafluoroethylene Composites

Singh JSK, Ching YC, Liu S, Ching KY, Razali S, Gan SN

Materials (Basel), 2018 Nov 02;11(11).
PMID: 30400137 DOI: 10.3390/ma11112164

Reinforcing polyoxymethylene (POM) with glass fibers (GF) enhances its mechanical properties, but at the expense of tribological performance. Formation of a transfer film to facilitate tribo-contact is compromised due to the abrasiveness of GF. As a solid lubricant, for example, polytetrafluoroethylene (PTFE) significantly improves friction and wear resistance. The effects of chemically etched PTFE micro-particles on the fiber-matrix interface of POM/GF/PTFE composites have not been systematically characterized. The aim of this study is to investigate their tribological performance as a function of micro-PTFE blended by weight percentage. Samples were prepared by different compositions of PTFE (0, 1.7, 4.0, 9.5, 15.0 and 17.3 wt.%). The surface energy of PTFE micro-particles was increased by etching for 10 min using sodium naphthalene salt in tetrahydrofuran. Tribological performance was characterized through simultaneous acquisition of the coefficient of friction and wear loss on a reciprocating test rig in accordance to Procedure A of ASTM G133-95. Friction and wear resistance improved as the micro-PTFE weight ratio was increased. Morphology analysis of worn surfaces showed transfer film formation, encapsulating the abrasive GF. Energy dispersive X-ray spectroscopy (EDS) revealed increasing PTFE concentration from the GF surface interface region (0.5, 1.0, 1.5, 2.0, 2.5 µm).
Preparation of aerogel beads and microspheres based on chitosan and cellulose for drug delivery: A review

Shi W, Ching YC, Chuah CH

Int J Biol Macromol, 2021 Feb 15;170:751-767.
PMID: 33412201 DOI: 10.1016/j.ijbiomac.2020.12.214

Spherical aerogels are not easily broken during use and are easier to transport and store which can be used as templates for drug delivery. This review summarizes the possible approaches for the preparation of aerogel beads and microspheres based on chitosan and cellulose, an overview to the methods of manufacturing droplets is presented, afterwards, the transition mechanisms from sol to a spherical gel are reviewed in detail followed by different drying processes to obtain spherical aerogels with porous structures. Additionally, a specific focus is given to aerogel beads and microspheres to be regarded as drug delivery carriers. Furthermore, a core/shell architecture of aerogel beads and microspheres for controlled drug release is described and subjected to inspire readers to create novel drug release system. Finally, the conclusions and outlooks of aerogel beads and microspheres for drug delivery are summarized.
Cellulose supported promising magnetic sorbents for magnetic solid-phase extraction: A review

Mhd Haniffa MAC, Ching YC, Illias HA, Munawar K, Ibrahim S, Nguyen DH, et al.

Carbohydr Polym, 2021 Feb 01;253:117245.
PMID: 33279000 DOI: 10.1016/j.carbpol.2020.117245

Cellulose with ample hydroxyl groups is considered as a promising supportive biopolymer for fabricating cellulose supported promising magnetic sorbents (CMS) for magnetic solid-phase extraction (MSPE). The easy recovery via external magnetic field, and recyclability of CMS, associated with different types and surface modifications of cellulose has made them a promising sorbent in the field of solid-phase extraction. CMS based sorbent can offer improved adsorption and absorption capabilities due to its high specific surface area, porous structure, and magnetic attraction feature. This review mainly focuses on the fabrication strategies of CMS using magnetic nanoparticles (MNPs) and various forms of cellulose as a heterogeneous and homogeneous solution either in alkaline mediated urea or Ionic liquids (ILs). Moreover, CMS will be elaborated based on their structures, synthesis, physical performance, and chemical attraction of MNPs and their MSPE in details. The advantages, challenges, and prospects of CMS in future applications are also presented.
Fulltext Review of Bionanocomposite Coating Films and Their Applications

Mhd Haniffa MAC, Ching YC, Abdullah LC, Poh SC, Chuah CH

Polymers (Basel), 2016 Jun 29;8(7).
PMID: 30974522 DOI: 10.3390/polym8070246

The properties of a composite material depend on its constituent materials such as natural biopolymers or synthetic biodegradable polymers and inorganic or organic nanomaterials or nano-scale minerals. The significance of bio-based and synthetic polymers and their drawbacks on coating film application is currently being discussed in research papers and articles. Properties and applications vary for each novel synthetic bio-based material, and a number of such materials have been fabricated in recent years. This review provides an in-depth discussion on the properties and applications of biopolymer-based nanocomposite coating films. Recent works and articles are cited in this paper. These citations are ubiquitous in the development of novel bionanocomposites and their applications.
Bio-based Poly(hydroxy urethane)s: Synthesis and Pre/Post-Functionalization

Mhd Haniffa MAC, Munawar K, Ching YC, Illias HA, Chuah CH

Chem Asian J, 2021 Jun 01;16(11):1281-1297.
PMID: 33871151 DOI: 10.1002/asia.202100226

New and emerging demand for polyurethane (PU) continues to rise over the years. The harmful isocyanate binding agents and their integrated PU products are at the height of environmental concerns, in particular PU (macro and micro) pollution and their degradation problems. Non-isocyanate poly(hydroxy urethane)s (NIPUs) are sustainable and green alternatives to conventional PUs. Since the introduction of NIPU in 1957, the market value of NIPU and its hybridized materials has increased exponentially in 2019 and is expected to continue to rise in the coming years. The secondary hydroxyl groups of these NIPU's urethane moiety have revolutionized them by allowing for adequate pre/post functionalization. This minireview highlights different strategies and advances in pre/post-functionalization used in biobased NIPU. We have performed a comprehensive evaluation of the development of new ideas in this field to achieve more efficient synthetic biobased hybridized NIPU processes through selective and kinetic understanding.
Synthesis of chitosan aerogels as promising carriers for drug delivery: A review

Wei S, Ching YC, Chuah CH

Carbohydr Polym, 2020 Mar 01;231:115744.
PMID: 31888854 DOI: 10.1016/j.carbpol.2019.115744

Chitosan with abundant functional groups is regarded as important ingredients for preparing aerogel materials in life science. The biocompatibility and biodegradability of chitosan aerogels, coupled to the variety of chemical functionalities they include, result in them promising carriers for drug delivery. Moreover, chitosan aerogels as drug delivery vehicles can offer improved drug bioavailability and drug loading capacity due to their highly porous network, considerably large specific surface area and polycationic feature. The major focus of this review lies in preparation methods of chitosan aerogels from acidic aqueous solution and chitosan solution in Ionic Liquids (ILs). In addition, chitosan aerogels as drug delivery carriers are introduced in detail and expected to inspire readers to create new kind of drug delivery system based on chitosan aerogels. Finally, growing points and perspectives of chitosan aerogels in drug delivery system are given.
Investigations on the interactions of proteins with nanocellulose produced via sulphuric acid hydrolysis

Gunathilake TMSU, Ching YC, Uyama H, Nguyen DH, Chuah CH

Int J Biol Macromol, 2021 Dec 15;193(Pt B):1522-1531.
PMID: 34740692 DOI: 10.1016/j.ijbiomac.2021.10.215

The investigation of protein-nanoparticle interactions contributes to the understanding of nanoparticle bio-reactivity and creates a database of nanoparticles for use in nanomedicine, nanodiagnosis, and nanotherapy. In this study, hen's egg white was used as the protein source to study the interaction of proteins with sulphuric acid hydrolysed nanocellulose (CNC). Several techniques such as FTIR, zeta potential measurement, UV-vis spectroscopy, compressive strength, TGA, contact angle and FESEM provide valuable information in the protein-CNC interaction study. The presence of a broader peak in the 1600-1050 cm-1 range of CNC/egg white protein FTIR spectrum compared to the 1600-1050 cm-1 range of CNC sample indicated the binding of egg white protein to CNC surface. The contact angle with the glass surface decreased with the addition of CNC to egg white protein. The FESEM EDX spectra showed a higher amount of N and Na on the surface of CNC. It indicates the density of protein molecules higher around CNC. The zeta potential of CNC changed from -26.7 ± 0.46 to -21.7 ± 0.2 with the introduction of egg white protein due to the hydrogen bonding, polar bonds and electrostatic interaction between surface CNC and protein. The compressive strength of the egg white protein films increased from 0.064 ± 0.01 to 0.36 ± 0.02 MPa with increasing the CNC concentration from 0 to 4.73% (w/v). The thermal decomposition temperature of CNC/egg white protein decreased compared to egg white protein thermal decomposition temperature. According to UV-Vis spectroscopy, the far-UV light (207-222nm) absorption peak slightly changed in the CNC/egg white protein spectrum compared to the egg white protein spectrum. Based on the results, the observations of protein nanoparticle interactions provide an additional understanding, besides the theoretical simulations from previous studies. Also, the results indicate to aim CNC for the application of nanomedicine and nanotherapy. A new insight given by us in this research assumes a reasonable solution to these crucial applications.

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