ABSTRACT
OBJECTIVES: The present study aimed to assess the attitude of Saudi and Pakistani individuals with diabetes regarding Eid-al-Fitr festivities, exploring diabetes care during the month of Ramadan and these individuals' dietary patterns on Eid day. DESIGN: Cross-sectional study. SETTING: Jeddah (Saudi Arabia) and Karachi (Pakistan). PARTICIPANTS: Of the total 405 subjects, 204 individuals with diabetes from Saudi Arabia (SA) and 201 from Pakistan (Pak) were enrolled. DATA COLLECTION AND ANALYSIS: This survey-based study was carried out in SA and Pak after Eid-al-Fitr 2020. An online questionnaire was circulated via various social media platforms. The data analyses were performed using SPSS V.26. RESULTS: There were 80 subjects with type 1 diabetes mellitus (DM) and 325 subjects with type 2 DM. Among our study subjects, 73 were on insulin, 260 were on oral antidiabetics (OADs) and 72 were taking both OADs and insulin. Two-thirds of the participants, 276 (68%) visited their physicians before Ramadan. Many participants (175, 43.2%) broke their fast a day or more because of diabetes. Many participants consumed sugary food on Eid day. The use of chocolates, sugary foods and fresh juices on Eid-al-Fitr was higher in Saudi subjects than in Pakistani ones (p<0.001). Saudi subjects with diabetes adhered more strictly to medications during Ramadan than Pakistani subjects (p=0.01). Saudi participants were more compliant with monitoring DM during Eid-al-Fitr compared with Pakistani subjects. Many participants in both groups felt stressed or depressed and stated that their Eid celebrations were restrictive because of their DM conditions. CONCLUSIONS: Most Saudi and Pakistani participants enjoyed Eid celebrations by abstaining from dietary restrictions. The sugar consumption attitude during Eid day was not up to the mark. Many subjects broke their fasts for a day or more because of diabetes. Saudis were more vigilant in monitoring DM than Pakistanis during Eid-al-Fitr. Individuals with diabetes should consult their physicians before Ramadan for checkups and counselling.
Subject(s)
Diabetes Mellitus , Fasting , Humans , Saudi Arabia , Pakistan , Cross-Sectional Studies , Hypoglycemic Agents/therapeutic use , Insulin/therapeutic use , Diabetes Mellitus/drug therapyABSTRACT
Chitosan was functionalized to synthesize Quaternized N-trimethyl chitosan (TMC) and incorporated in polyethersulfone (PES) polymer to fabricate membranes for enhanced antifungal activity and water treatment. The TMC was synthesized from chitosan via reductive alkylation and methylation. The effect of concentration of chitosan and TMC on the properties of functionalized PES membranes was investigated. The membrane with the lowest concentration of TMC 5% (w/w) resulted in the largest average pore size than the PES membrane without chitosan or TMC. The surface wettability was enhanced as contact angle was reduced from 90° to 57° by increasing concentration of TMC to 15% (w/w). The resultant membranes exhibited improved water hydrophilicity, permeability and inhibition against fungal species. The functionalized membranes had shown noticeable antifungal activity against Aspergillus niger in the case of 15% TMC with 72% antifungal activity and 15% chitosan with 63% antifungal activity against Fusarium solani.
Subject(s)
Antifungal Agents/pharmacology , Chitosan/pharmacology , Drinking Water/microbiology , Membranes, Artificial , Quaternary Ammonium Compounds/pharmacology , Antifungal Agents/chemical synthesis , Antifungal Agents/chemistry , Aspergillus niger/drug effects , Chitosan/chemical synthesis , Chitosan/chemistry , Fusarium/drug effects , Hydrophobic and Hydrophilic Interactions , Permeability , Polymers/chemistry , Porosity , Quaternary Ammonium Compounds/chemical synthesis , Quaternary Ammonium Compounds/chemistry , Sulfones/chemistry , Water Purification/instrumentation , WettabilityABSTRACT
Currently a variety of tools and techniques are used to deliver complex medicines. Whereas, certain advanced methods assure the safety and usefulness by regulating the pharmacokinetic and pharmacodynamic. Thus, we aimed this study to develop a novel gastro retentive floating tablets. The formulation was designed to provide the desired controlled and complete release of drug for prolonged period of time. The formulations were evaluated for physical characterization. The obtained results of hardness (4.6-5.1), friability (0.20-0.43%), weight variation (350 ±2 - 350±5) and in vitro buoyancy were found within official limits of United Stated Pharmacopoeia (USP). Whereas, the F-7 showed most optimized intra gastric floating characteristics and exhibited 93.87% release of diclofenac sodium in 9 hours. The Floating Lag Time of 8 minutes and Total Floating Time >12 hours were recorded. In-vitro drug release kinetics evaluated using the linear regression method was found to follow the Zero Order and Peppas model for the release of both the drugs. DSC thermograph and FTIR spectra depicted that there was no chemical incompatibility between drugs and polymers. In conclusion the desgined tablet can be use in clinical practice as model drug. Because, the pre-compression and post-compression parameters were satisfactory and within desired limits.
Subject(s)
Diclofenac/administration & dosage , Drug Compounding/methods , Delayed-Action Preparations/administration & dosage , Delayed-Action Preparations/pharmacokinetics , Diclofenac/pharmacokinetics , Drug Liberation , Humans , Spectroscopy, Fourier Transform Infrared , TabletsABSTRACT
Novel pH-sensitive γ-irradiated low molecular weight (MW) chitosan (CS) (pre-irradiated) and poly (vinyl alcohol) (PVA) blended injectable hydrogels, crosslinked with varying concentrations of glycerol, were fabricated for drug delivery application. The effect of low MW irradiated CS on controlled drug release was evaluated to address the problem of higher viscosity and lower solubility of high MW CS. The FTIR spectra of hydrogels depicted the presence of all the incorporated functional groups and the developed interactions (physical and chemical). The surface morphology of hydrogels assessed by scanning electron microscope exhibited porous microstructure. All hydrogels were subjected to the swelling analysis in different media (water, buffer and electrolytes). The pH sensitive hydrogel samples exhibited less swelling at acidic and neutral pH while higher swelling at basic pH. CPG-0.5 showed the highest swelling at all pH media as compared to other hydrogel samples. CPG-1.0 was selected for the release analysis of drug because of its highest swelling (114.47%) in distilled water having neutral pH. It was loaded with model drug (Montelukast Sodium) during the preparation phase and studied for drug release capability. The in-vitro controlled release evaluation of hydrogel (CPG-1.0) was performed in SGF and SIF using UV-visible spectroscopy. The results confirmed their applications in injectable drug release systems as all the loaded drug was released in 30â¯min in SGF (pHâ¯-1.2) while the release of drug in SIF (pHâ¯-6.8) was in controlled manner (99.62% in 3â¯h). The improved antibacterial activity of these hydrogel films was owing to the fact that the γ-irradiated low MW CS has ruptured the bacterial cell and its metabolism more efficiently by inflowing in the cell.
Subject(s)
Acetates/administration & dosage , Quinolines/administration & dosage , Chitosan/administration & dosage , Chitosan/chemistry , Chitosan/radiation effects , Cross-Linking Reagents/pharmacology , Cyclopropanes , Delayed-Action Preparations , Drug Delivery Systems , Drug Evaluation, Preclinical , Drug Liberation , Escherichia coli/drug effects , Gamma Rays , Glycerol/pharmacology , Hydrogels/administration & dosage , Hydrogels/chemistry , Hydrogels/radiation effects , Hydrogen Bonding , Hydrogen-Ion Concentration , Hydrophobic and Hydrophilic Interactions , Microscopy, Electron, Scanning , Molecular Weight , Polyvinyl Alcohol/administration & dosage , Porosity , Spectrophotometry, Ultraviolet , Spectroscopy, Fourier Transform Infrared , SulfidesABSTRACT
In this work, we developed hybrid membranes integrated with Nanocrystalline cellulose (NCC)/Gum Arabic (GuA) conjugates using crosslinked Poly (vinyl alcohol) (PVA) as a matrix phase with the addition of PEO-PPO-PEO block copolymer that insured pore formation. At first, the NCC was prepared from microcrystalline cellulose via acid hydrolysis process. The performance property of hybrid NCC/GuA was measured using boron removal. The results showed that the rejection capability enhanced as compared to the control membranes, especially at 0.1wt% of NCC the selectivity is up to 92.4% with the flux rate of 21.3L/m2.h. Moreover, the GuA in NCC/GuA conjugate significantly enhances the antibacterial activity by hindering the bacterial attachment to the surface as both of them carry the negative charge. Also by providing the active sites responsible for hydrogen bonding thus enhancing the hydrophilic character resulted in increased permeation flux rate. Therefore, the NCC/GuA conjugated membranes have great potentials for boron removal.
Subject(s)
Anti-Bacterial Agents/chemistry , Boron/chemistry , Cellulose/chemistry , Gum Arabic/chemistry , Membranes, Artificial , Nanoparticles/chemistry , Water Purification/instrumentation , Chlorine/chemistry , Cross-Linking Reagents/chemistry , Drug Resistance, Bacterial , Escherichia coli/drug effects , Polyethylene Glycols/chemistry , Polyvinyl Alcohol/chemistry , Propylene Glycols/chemistry , Silanes/chemistry , Water Purification/methodsABSTRACT
Spigelian hernias are a rare defect in the Spigelian aponeurosis, comprising of 0.1-2% of all hernias. These rare hernias can contain intra-abdominal tissue, and rarely bladder. Spigelian hernias pose a high risk for incarceration or strangulation of its herniated content if not repaired promptly. There are a number of routinely employed operative techniques to repair Spigelian hernias, including open or laparoscopic, suture or mesh repair, transabdominal pre-peritoneal approach or totally extraperitoneal approach. Robotic Spigelian repairs have been rarely reported in the literature. We report three cases of incarcerated Spigelian hernias that were successfully repaired robotically with mesh.
Subject(s)
Hernia, Abdominal/surgery , Robotic Surgical Procedures/methods , Abdomen/diagnostic imaging , Aged , Humans , Male , Robotic Surgical Procedures/instrumentation , Surgical Mesh , Tomography, X-Ray ComputedABSTRACT
Novel biodegradable films were prepared by blending guar gum, chitosan and poly (vinyl alcohol) having mint (ME) and grapefruit peel (GE) extracts and crosslinked with nontoxic tetraethoxysilane (TEOS). The co-concentration effect of TEOS with natural extracts on the films was studied. FTIR analysis confirmed the presence of incorporated components and the developed interactions among the polymer chains. The surface morphology of the films by SEM showed the hydrophilic character due to porous network structure. The films having both ME and GE with maximum amount of crosslinker (100µL), showed maximum swelling (58g/g) and stability while the optical properties showed increased protection against UV light. This film sample showed compact network structure which enhanced the ultimate tensile strength (40.03MPa) and elongation at break (104.8%). ME/GE conferred the antioxidant properties determined by radical scavenging activity and total phenolic contents (TPC) as ME films have greater TPC compared to GE films. The soil burial test exhibited the degradation of films rapidly (6days) confirming their strong microbial activity in soil. The lower water vapour transmission rate and water vapour permeability showed better shelf life; hence, these biodegradable films are environmental friendly and have potential for food and other packaging.
Subject(s)
Chitosan/chemistry , Food Packaging/methods , Galactans/chemistry , Mannans/chemistry , Plant Extracts/chemistry , Plant Gums/chemistry , Silanes/chemistry , Biodegradation, Environmental , Citrus paradisi/chemistry , Cross-Linking Reagents/chemistry , Humans , Membranes, Artificial , Mentha/chemistry , Polyvinyl Alcohol/chemistry , Porosity , Steam/analysis , Tensile Strength , Ultraviolet RaysABSTRACT
The report presents the formulation of hydrogel based on biopolymers chitosan and guar gum after cross-linking for sustained release of a commonly used orally prescribed analgesic Paracetamol. The oral ingestion of Paracetamol is associated with complications of the gastric tract and liver metabolism that can be effectually avoided by using transdermal drug delivery systems. The formulated transdermal patch was characterized for physicochemical properties including swelling, bonding pattern (using FTIR Fourier Transform Infra-Red and Scanning Electron Microscopy SEM) and antimicrobial activity. Biocompatibility and cytotoxicity was examined in vitro using cell culture in HeLa cell lines. After characterizing the novel formulated hydrogel were employed for the preparation of drug encapsulated in alginate beads as a transdermal patch. After formulation of the transdermal patch, the drug release was studied using an avian skin model. The results followed zero order kinetics and Non-Fickian law for diffusion. Paracetamol due to its small molecular mass (151.163g/mol) released in a sustained manner. The released drug successfully retained its biological effects including anti-inflammatory and anti-protease activity, indicating no interaction between the drug and the formulated hydrogel. It was shown that the formulated hydrogels could be safely used as a dermal patch for the sustained drug release of Paracetamol.
Subject(s)
Acetaminophen/administration & dosage , Acetaminophen/chemistry , Chitosan/chemistry , Drug Carriers/chemistry , Galactans/chemistry , Hydrogels/chemistry , Mannans/chemistry , Plant Gums/chemistry , Acetaminophen/pharmacokinetics , Animals , Anti-Infective Agents/chemistry , Anti-Infective Agents/pharmacology , Cell Line , Cell Survival/drug effects , Chickens , Delayed-Action Preparations , Diffusion , Drug Compounding , Drug Liberation , Humans , Spectroscopy, Fourier Transform InfraredABSTRACT
Antifouling polyethersulfone (PES) membranes for water disinfection were fabricated by incorporating varying concentrations of carbohydrate polymer chitosan and Zinc oxide hybrid nanoparticles (CS-ZnO HNPS). The CS-ZnO HNPS were prepared using chemical precipitation method and were characterized using SEM, XRD and FTIR. The membranes were then fabricated by incorporating nanoparticles of CS-ZnO HNPS with three different concentrations of 5%, 10% and 15% w/w in the casting solution of PES through phase inversion method. The influence of nano-sized CS-ZnO HNPS on the properties of PES was characterized to study morphology, contact angle, water retention, surface roughness and permeability flux. The membranes with the maximum concentrations of 15% HNPS resulted in larger mean pore sizes and lowest contact angle value as compare to the pristine PES membrane. The prepared membranes exhibited significant water permeability, hydrophilicity and prevention against microbial fouling. The prepared membranes were observed to have significant antibacterial as well as antifungal properties due to the synergistic effect of chitosan and ZnO against both bacteria of the type of S. Aureus, B. Cereus, E. coli, and fungi such as S. typhi, A. fumigatus and F. solani.
ABSTRACT
Inspired by the hydrophilic, biocompatible, adsorbent properties of chitosan. A simple, adaptable, green synthesis method was developed to prepare a thin film composite membranes using chitosan as a pore decorating material for the removal of anionic dye-Reactive orange 16 (RO-16). The hydrophilic chitosan was used to fill up the porous hydrophobic PVDF substrate, modified by MWCNTs. The dye rejection was carried out through the formation of a strong electrostatic interaction between the cationic group of chitosan surface and the anionic group of RO-16 dye. The dye molecules accumulate on the chitosan surface, thus promoting the higher retention rate. The TFC membranes were evaluated using dead filtration plant. It is found that the modified membranes showed RO-16 rejection up to 91% with optimum permeation flux of 170kgm-2h-1. Furthermore, the presence of chitosan on MWCNT/PVDF substrate provides a hydrophilic character thus decreasing the active sites available for foulant attachment which is confirmed by the fouling study. The CTAB foulant showed an increase in flux rate even after physical flushing. The modification procedure is performed under mild conditions, thus it is helpful to fabricate TFC membrane at a commercial scale.
ABSTRACT
Silane crosslinked biopolymer based novel pH-responsive hydrogels were fabricated by blending the cationic (chitosan) and anionic (alginate) polymers with poly(vinyl alcohol). Tetraethoxysilane (TEOS) was used, as a crosslinker in different amounts due to its nonhazardous nature, to study its impact on physical and chemical properties of the prepared injectable hydrogels along with the controlled release of drug. The swelling response of the prepared hydrogels was examined in different solvent media which exhibited decreased swelling ratio with increase in the amount of TEOS. All the fabricated hydrogels represented highest swelling at acidic pH while low swelling at basic and neutral pH. This specific pH sensitive behavior at pH 7 made them an appropriate candidate for the injectable controlled drug delivery in which Neomycin Sulfate (NMS) was successfully loaded on suitable hydrogel (comprising 50µL TEOS) to study its release mechanism. The results revealed that in simulated gastric fluid (SGF), hydrogel released the entire drug (NMS) in initial 30min while in simulated intestinal fluid (SIF), NMS was released in a controlled way up to 83% in 80min. These results endorsed that the hydrogels could be practiced as a smart intelligent material for injectable controlled drug delivery as well as for other biomedical applications at physiological pH.
Subject(s)
Drug Carriers/chemistry , Hydrogels/chemistry , Neomycin/chemistry , Silanes/chemistry , Anti-Bacterial Agents/chemistry , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/toxicity , Buffers , Delayed-Action Preparations , Drug Carriers/pharmacology , Drug Carriers/toxicity , HeLa Cells , Humans , Hydrogels/pharmacology , Hydrogels/toxicity , Injections , Water/chemistryABSTRACT
Blended membranes of polyurethane and cellulose acetate were prepared, characterized and investigated for their performance. Various ratios of cellulose acetate were employed to prepare four different blend membranes. The characteristics of both pure and blend membranes were investigated and results were compared to distinguish their properties. Functional group analysis was carried out by attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) of pure and blend samples. Contact angle measurement and water content were evaluated to determine the membrane hydrophilicity. Moreover, the membrane morphology was studied by scanning electron microscopy (SEM). The membrane permeation properties and ability to reject chromium (VI) ions were tested at various pH and pressure by utilizing different salt concentrations.
Subject(s)
Cellulose/analogs & derivatives , Chromium/isolation & purification , Membranes, Artificial , Polyurethanes/chemistry , Water Pollutants, Chemical/isolation & purification , Water Purification/instrumentation , Cellulose/chemical synthesis , Cellulose/chemistry , Equipment Design , Hydrogen-Ion Concentration , Permeability , Polyurethanes/chemical synthesis , Water/analysis , Water Purification/methodsABSTRACT
Novel silane crosslinked tough hydrogel scaffolds were prepared using chitosan (CS) and polyvinyl alcohol (PVA) to give network structure and scaffolds properties. The influence of crosslinking and PVA concentration on scaffolds were studied. Fourier transform infrared spectroscopy (FTIR) spectroscopy confirmed the presence of incorporated components. Tensile strength (TS) and fracture strain analysis of scaffolds were detected owing to the mutual effect of chemically and physically crosslinked network. Tough hydrogel scaffolds having 90% CS and 10% PVA exhibited TS of 49.18MPa and 10.15% elongation at break. The contact angle is less than 90° exhibited the hydrophilic nature of the scaffold. X-ray diffraction analysis (XRD) indicated the characteristics peaks fitting to CS and PVA and increase in the crystallinity of scaffolds. Cytotoxicity of scaffolds with different human fibroblast cell lines (F121, F192 and F84) for indirect method and human dermal fibroblast cell lines (F121) for direct method was evaluated. This indicated that these biomaterials were non-toxic, viable to the used cell lines, helpful in the growth of these cells and did not discharge toxic material damaging to the living cells.
Subject(s)
Chitosan , Fibroblasts/metabolism , Hydrogels , Materials Testing , Polyvinyl Alcohol , Tissue Scaffolds/chemistry , Cell Line , Chitosan/chemistry , Chitosan/pharmacology , Humans , Hydrogels/chemistry , Hydrogels/pharmacology , Polyvinyl Alcohol/chemistry , Polyvinyl Alcohol/pharmacologyABSTRACT
Cellulose acetate/Polyethylene glycol-600 composite membranes were fabricated by two step phase inversion procedure and modified by in-situ reduction of silver nitrate. FTIR spectra demonstrated the existence of functional groups for bonding of silver with oxygen at 370cm(-1), 535cm(-1). The XRD diffractogram indicates characteristic peaks at 2θ values of 38.10°, 44.30°, 64.40°, and 77.30° which confirm the successful incorporation of silver within matrix of composite membranes. The morphology of composite membranes with appearances of spongy voids was exemplified from the scanning electron microscope. The atomic force microscopy was used to determine the increase in the surface roughness of the membranes. The increase in hydrophilicity, measured through contact angle, is rendered to the embedment of silver. The modification of membranes increased the flux from 0.80 to 0.95L/hr.m(2). The resulting membranes have outstanding ability to fight against gram negative Escherichia Coli and Bacillus Sabtilus. The novel cellulose acetate/polyethylene glycol membranes customized with silver have paved the path for evolution of axenic membranes.
Subject(s)
Anti-Bacterial Agents/chemistry , Cellulose/analogs & derivatives , Membranes, Artificial , Polyethylene Glycols/chemistry , Salinity , Water Purification/methods , Water/chemistry , Anti-Bacterial Agents/pharmacology , Bacillus/drug effects , Cellulose/chemistry , Cellulose/pharmacology , Escherichia coli/drug effects , Permeability , Sterilization , Water Purification/instrumentationABSTRACT
Graphene oxide (GO) was indigenously synthesized from graphite using standard Hummers method. Chitosan-graphene oxide green composite films were fabricated by mixing aqueous solution of chitosan and GO using dilute acetic acid as a solvent for chitosan. Chitosan of different viscosity and calculated molecular weight was used keeping amount of GO constant in each composite film. The structural properties, thermal stability and mechanical properties of the composite films were investigated using Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), thermogravimetric analysis (TGA) and tensile test. FTIR studies revealed the successful synthesis of GO from graphite powder and it was confirmed that homogenous blending of chitosan and GO was promising due to oxygenated functional groups on the surface of GO. XRD indicated effective conversion of graphite to GO as its strong peak observed at 11.06° as compared to pristine graphite which appeared at 26°. Moreover, mechanical analysis confirmed the effect of molecular weight on the mechanical properties of chitosan-GO composites showing that higher molecular weight chitosan composite (GOCC-1000) showed best strength (higher than 3GPa) compared to other composite films. Thermal stability of GOCC-1000 was enhanced for which residual content increased up to 56% as compared to the thermal stability of GOCC-200 whose residue was restricted to only 24%. The morphological analysis of the composites sheets by SEM was smooth having dense structure and showed excellent interaction, miscibility, compatibility and dispersion of GO with chitosan. The prepared composite films find their applications as biomaterials in different biomedical fields.
Subject(s)
Biocompatible Materials/chemical synthesis , Chitosan/chemistry , Graphite/chemistry , Oxides/chemistry , X-Ray DiffractionABSTRACT
Selected properties of chitosan (CS) and poly(vinyl alcohol) (PVA) blends crosslinked by tetraethoxysilane (TEOS) were studied. XRD analysis showed characteristics peak at 22.5° attributed to the crystalline structure of CS and PVA. DSC thermograms unveiled the quantitative determination of free, intermediate and bound water in the blends. Tensile strength and fracture strain of blends were observed due to the combined effect of physically and chemically crosslinked network structures. The decrease in water contact angle indorsed the hydrophilic performance while the storage modulus G' and loss modulus Gâ³ was decreased as the temperature was increased exhibited the viscoelastic property of the blends. The fabricated blends can be employed for drug delivery systems, tissue engineering and other biomedical applications.
Subject(s)
Biocompatible Materials/chemistry , Chitosan/chemistry , Polyvinyl Alcohol/chemistry , Biomechanical Phenomena , Calorimetry, Differential Scanning , Elasticity , Hydrogels/chemistry , Polymers/chemistry , Rheology , Temperature , Viscosity , X-Ray DiffractionABSTRACT
Thermally-induced phase separation (TIPS) method was used to synthesize polymer matrix (PM) membranes for reverse osmosis from cellulose acetate/polyethylene glycol (CA/PEG300) conjugated with silica nanoparticles (SNPs). Experimental data showed that the conjugation of SNPs changed the surface properties as dense and asymmetric composite structure. The results were explicitly determined by the permeability flux and salt rejection efficiency of the PM-SNPs membranes. The effect of SNPs conjugation on MgSO4 salt rejection was more significant in magnitude than on permeation flux i.e. 2.38 L/m(2)h. FTIR verified that SNPs were successfully conjugated on the surface of PM membrane. DSC of PM-SNPs shows an improved Tg from 76.2 to 101.8 °C for PM and PM-S4 respectively. Thermal stability of the PM-SNPs membranes was observed by TGA which was significantly enhanced with the conjugation of SNPs. The micrographs of SEM and AFM showed the morphological changes and increase in the valley and ridges on membrane surface. Experimental data showed that the PM-S4 (0.4 wt% SNPs) membrane has maximum salt rejection capacity and was selected as an optimal membrane.
Subject(s)
Cellulose/analogs & derivatives , Membranes, Artificial , Nanoparticles/chemistry , Osmosis , Polyethylene Glycols/chemistry , Silicon Dioxide/chemistry , Cellulose/chemistry , Magnesium Sulfate/chemistryABSTRACT
In this study pristine multi-walled carbon nanotubes (MWCNTs) were surface engineered (SE) in strong acidic medium by oxidation purification method to form SE-MWCNT. Five different amount of SE-MWCNT ranging from 0.1 to 0.5 wt% were thoroughly and uniformly dispersed in cellulose acetate/polyethylene glycol (CA/PEG400) polymer matrix during synthesis of membrane by dissolution casting method. The structural analysis, surface morphology and roughness was carried out by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and atomic force microscopy (AFM), respectively, which showed that the dispersed SE-MWCNT was substantially tethered in CA/PEG400 polymer matrix membrane. The thermogravimetric analysis (TGA) of membranes also suggested some improvement in thermal properties with the addition of SE-MWCNT. Finally, the performance of these membranes was assessed for suitability in drinking water treatment. The permeation flux and salt rejection were determined by using indigenously fabricated reverse osmosis pilot plant with 1000 ppm NaCl feed solution. The results showed that the tethered SE-MWCNT/CA/PEG400 polymer matrix membrane, with strong SE-MWCNTs/polymer matrix interaction, improved the salt rejection performance of the membrane with the salt rejection of 99.8% for the highest content of SE-MWCNT.
Subject(s)
Cellulose/analogs & derivatives , Membranes, Artificial , Nanotubes, Carbon/chemistry , Polyethylene Glycols/chemistry , Cellulose/chemistry , Microscopy, Atomic Force , Microscopy, Electron, Scanning , Spectroscopy, Fourier Transform Infrared , Water/chemistry , Water PurificationABSTRACT
Biopolymer based pH-sensitive hydrogels were prepared using chitosan (CS) with polyethylene glycol (PEG) of different molecular weights in the presence of silane crosslinker. The incorporated components remain undissolved in different swelling media as they are connected by siloxane linkage which was confirmed by Fourier transform infrared spectroscopy. The swelling in water was enhanced by the addition of higher molecular weight PEG. The swelling behaviour of the hydrogels against pH showed high swelling in acidic and basic pH, whereas, low swelling was examined at pH 6 and 7. This characteristic pH responsive behaviour at neutral pH made them suitable for injectable controlled drug delivery. The controlled release analysis of Cefixime (CFX) (model drug) loaded CS/PEG hydrogel exhibited that the entire drug was released in 30 min in simulated gastric fluid (SGF) while in simulated intestinal fluid (SIF), 85% of drug was released in controlled manner within 80 min. This inferred that the developed hydrogels can be an attractive biomaterial for injectable drug delivery with physiological pH and other biomedical applications.
Subject(s)
Chitosan/chemistry , Drug Carriers/chemistry , Hydrogels/chemistry , Anti-Bacterial Agents/chemistry , Anti-Bacterial Agents/pharmacology , Bacteria/drug effects , Cefixime/chemistry , Delayed-Action Preparations , Drug Carriers/pharmacology , Drug Liberation , Hydrogels/pharmacology , Hydrogen-Ion Concentration , Injections , Molecular Weight , Polyethylene Glycols/chemistry , Silanes/chemistryABSTRACT
The surface of the cellulosic fabrics was modified using self-prepared emulsions of polyurethane acrylate copolymers (PUACs). PUACs were prepared by varying the molecular weight of polycaprolactone diol (PCL). The PCL was reacted with isophorone diisocyanate (IPDI) and chain was extended with 2-hydroxy ethyl acrylate (HEA) to form vinyl terminated polyurethane (VTPU) preploymer. The VTPU was further co-polymerized through free radical polymerization with butyl acrylate in different proportions. The FT-IR spectra of monomers, prepolymers and copolymers assured the formation of proposed PUACs structure. The various concentrations of prepared PUACs were applied onto the different fabric samples using dip-padding techniques. The results revealed that the application of polyurethane butyl acrylate copolymer showed a pronounced effect on the tear strength and pilling resistance of the treated fabrics.