scholarly journals Synthesis of Biomaterial-Based Hydrogels Reinforced with Cellulose Nanocrystals for Biomedical Applications

2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Pavan Kumar Dara ◽  
Mahadevan Raghavankutty ◽  
Karthik Deekonda ◽  
Anil Kumar Vemu ◽  
Visnuvinayagam Sivam ◽  
...  

Cellulose nanocrystals (CNC) were prepared by formic acid hydrolysis and TEMPO- (2,2,6,6-tetramethyl-piperidine-1-oxyl-) mediated oxidation. The prepared CNCs were reinforced into biopolymers chitosan (CHI), alginate (ALG), and gelatin (GEL) to obtain “CNC-ALG-GEL” and “CNC-CHI-GEL” hydrogels. The synthesized hydrogels were characterized for physicochemical, thermal, and structural characterization using Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), thermal gravity analysis (TGA), and X-ray diffraction (XRD) analyses. Notably, the reinforcement of CNC has not altered the molecular structure of a biopolymer as revealed by FT-IR analysis. The hydrogels reinforced with CNC have shown better thermal stability and miscibility as revealed by thermal gravity analysis. The physicochemical, thermal, and structural characterization revealed the chemical interaction and electrostatic attraction between the CNC and biopolymers. The biocompatibility was investigated by evaluating the viability of the L929 fibroblast cell, which represents good biocompatibility and nontoxic nature. These hydrogels could be implemented in therapeutic biomedical research and regenerative medicinal applications.


Materials ◽  
2018 ◽  
Vol 11 (9) ◽  
pp. 1725 ◽  
Author(s):  
Xiaohong Liu ◽  
Ming Li ◽  
Xuemei Zheng ◽  
Elias Retulainen ◽  
Shiyu Fu

As a type of functional group, azo-derivatives are commonly used to synthesize responsive materials. Cellulose nanocrystals (CNCs), prepared by acid hydrolysis of cotton, were dewatered and reacted with 2-bromoisobuturyl bromide to form a macro-initiator, which grafted 6-[4-(4-methoxyphenyl-azo) phenoxy] hexyl methacrylate (MMAZO) via atom transfer radical polymerization. The successful grafting was supported by Fourier transform infrared spectroscopy (FT-IR) and Solid magnetic resonance carbon spectrum (MAS 13C-NMR). The morphology and surface composition of the poly{6-[4-(4-methoxyphenylazo) phenoxy] hexyl methacrylate} (PMMAZO)-grafted CNCs were confirmed with Transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). The grafting rate on the macro-initiator of CNCs was over 870%, and the polydispersities of branched polymers were narrow. The crystal structure of CNCs did not change after grafting, as determined by X-ray diffraction (XRD). The polymer PMMAZO improved the thermal stability of cellulose nanocrystals, as shown by thermogravimetry analysis (TGA). Then the PMMAZO-grafted CNCs were mixed with polyurethane and casted to form a composite film. The film showed a significant light and pH response, which may be suitable for visual acid-alkali measurement and reversible optical storage.



Polymers ◽  
2018 ◽  
Vol 10 (8) ◽  
pp. 896 ◽  
Author(s):  
Qiqi Fan ◽  
Guangping Han ◽  
Wanli Cheng ◽  
Huafeng Tian ◽  
Dong Wang ◽  
...  

In this work, an easy way to prepare the polylactic acid (PLA)/wheat straw fiber (WSF) composite was proposed. The method involved uses either the dopamine-treated WSF or the two-step montmorillonite (MMT)-modified WSF as the filler material. In order to achieve the dispersibility and exfoliation of MMT, it was modified by 12-aminododecanoic acid using a two-step route. X-ray diffraction (XRD) and scanning electron microscopy (SEM) were performed to characterize the modified MMT and the coated WSF. As for the properties of PLA/WSF composites, some thermal (using Fourier transform infrared spectroscopy (FT-IR) and thermogravimetric analysis) and mechanical properties (flexural, tensile, and impact) were analyzed. The results showed that the dopamine was successfully coated onto the WSF. Furthermore, Na-MMT was successfully transformed to organo-montmorillonite (OMMT) and formed an exfoliated structure. In addition, a better dispersion of MMT was obtained using the two-step treatment. The interlayer spacing of modified MMT was 4.06 nm, which was 123% higher than that of the unmodified MMT. Additionally, FT-IR analysis suggested that OMMT diffused into the PLA matrix. The thermogravimetric analysis (TGA) showed that a higher thermal stability of PLA/WSF composites was obtained for the modified MMT and dopamine. The results also showed that both the dopamine treated WSF and the two-step-treated MMT exhibited a positive influence on the mechanical properties of PLA/WSF composites, especially on the tensile strength, which increased by 367% compared to the unmodified precursors. This route offers researchers a potential scheme to improve the thermal and mechanical properties of PLA/WSF composites in a low-cost way.



2016 ◽  
Vol 675-676 ◽  
pp. 209-212 ◽  
Author(s):  
Wichian Siriprom ◽  
Nirun Witit-Anun ◽  
Auttapol Choeysuppaket ◽  
T. Ratana

In this study were to explore the properties of interaction between cellulose and calcium carbonate particle (CaCO3) which derive from Papia Undulates Shell in procedure of biocomposite synthesis. The structural properties of cellulose powder Papia Undulates Shell and cellulose-calcium carbonate composite film were investigated by using X-ray Diffraction (XRD) and Fourier transform infrared spectroscopy (FT-IR) and the compositions of cellulose/CaCO3 biocomposite film were studied by Energy Dispersive X-ray Fluorescence (EDXRF). The experimental results demonstrated the morphology of Papia Undulates Shell were crystalline aragonite phase and the cellulose have structural as amorphous-crystalline but after film forming the composite film between cellulose and Papia Undulates Shell also have amorphous structural. The result of FTIR used to confirmed the formation of bonding between molecular, it indicated that the cellulose/CacO3 biocomposite film had good biocompatibility due to the biocomposite film have both characteristic feature of CO3-2 group (~874 cm-1 and ~713 cm-1) and the glucose of cellulose at ~1635, ~1064 and ~946 cm-1. Another that, the result from EDXRF shown the chemical composition of organic compound of cellulose/CaCO3 biocomposite film was highest with 99.437 while the Papia Undulates Shell have 0.341 Wt% with corresponding with the ratio of filler material which mixture as 1%. So that, the cellulose/calcium carbonate bicomposite film could be candidate for biocomposite film application.



2011 ◽  
Vol 10 (03) ◽  
pp. 441-445 ◽  
Author(s):  
M. KARL CHINNU ◽  
L. SARAVANAN ◽  
R. JAYAVEL ◽  
C. M. RAGHAVAN ◽  
K. VIJAI ANAND ◽  
...  

Cadmium sulfide nanoparticles have been synthesized by hydrothermal method using cadmium acetate, thiosemicarbazide, and sodium hydroxide as precursors with hexamethylene tetramine as the surfactant. From the X-ray diffraction analysis, it is observed that synthesized CdS nanoparticles show cubic phase. The presence of HMTA in CdS was confirmed by FT-IR analysis. The bandgap value of CdS nanostructure has been estimated by DRS–UV-Visible spectral analysis. The formation of flower-like nanoclusters was observed using scanning electron microscopy (SEM). The application of CdS nanoparticles in photocatalytic degradation was also studied.



Polymers ◽  
2021 ◽  
Vol 13 (23) ◽  
pp. 4187
Author(s):  
Huifang Xie ◽  
Xin Ma ◽  
Wenbin Lin ◽  
Shiting Dong ◽  
Qiang Liu ◽  
...  

In the current study, linear dextrin (LD) was prepared using waxy potato starch debranched with pullulanase, which has attracted immense interest in the food, pharmaceutical, and cosmetic industries as a versatile ingredient. Various LDs were separated on the basis of their differential solubility in aqueous/ethanol solutions of different volumetric ratios. Three LD products—LD Fabrications with 40% ethanol (F-40); LD Fabrications with 50% ethanol (F-50); and LD Fabrications with 60%, 70%, and 80% ethanol (F-M)—were obtained with an average degree of polymerization (DP) values of 31.44, 21.84, and 16.10, respectively. The results of Fourier transform infrared spectroscopy (FT-IR) analysis revealed that the reaction mainly involved hydrogen bonding and a hydrophobic interaction between LD and insulin in the process of inclusion complex formation. X-ray diffraction (XRD) results indicated that insulin was encapsulated in LD. The results of circular dichroism (CD) showed that the changes in the secondary structure of insulin were negligible during the release from the inclusion complexes. The order of encapsulation capacity is as follows: the complex composed of F-M and insulin (F-M-INS) > the complex composed of LD and insulin (LD-INS) > the complex composed of F-50 and insulin (F-50-INS) > and the complex composed of F-40 and insulin (F-40-INS). F-M-INS inclusion complexes showed a better effect on reducing the release of insulin in gastric juice and promoting the release of insulin in intestinal juice and blood plasma than LD-INS.



2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Zulnazri Zulnazri ◽  
Rozanna Dewi ◽  
Sulhatun Sulhatun ◽  
Nasrun Nasrun

The aim of this study was to hydrolyzed cellulose nanocrystals as cellulose-based biomass residues from oil palm by using hydrochloric acid under hydrothermal conditions. The characterization of cellulose nanocrystals was determined by FT-IR spectroscopy and X- ray diffraction. The infrared spectroscopy showed there has been a removal of lignin and hemicellulose in the spectrum. Crystallinity which reaches 78.59% was obtained by hydrolysis using hydrochloric acid catalyst 3 mol/L with a reaction time of 1 hour. Based on the graph of -ln CA/CA0 vs. time obtained that Cellulose nanocrystals forming reaction is of first order. The reaction rate constants to the formation of glucose (k2) is greater than the reaction rate constant to the formation of Cellulose nanocrystals (k1), which indicates that the phase of slow reaction is the reaction of the most influential on the overall reaction rate, the reaction of the formation of Cellulose nanocrystals.



Crystals ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1125
Author(s):  
Dovydas Karoblis ◽  
Ramunas Diliautas ◽  
Eva Raudonyte-Svirbutaviciene ◽  
Kestutis Mazeika ◽  
Dalis Baltrunas ◽  
...  

In this study, the aqueous sol-gel method was employed for the synthesis of (1−x)SrTiO3-xBiMnO3 solid solutions. Powder X-ray diffraction analysis confirmed the formation of single-phase perovskites with a cubic structure up to x = 0.3. A further increase of the BiMnO3 content led to the formation of a negligible amount of neighboring Mn3O4 impurity, along with the major perovskite phase. Infrared (FT-IR) analysis of the synthesized specimens showed gradual spectral change associated with the superposition effect of Mn-O and Ti-O bond lengths. By introducing BiMnO3 into the SrTiO3 crystal structure, the size of the grains increased drastically, which was confirmed by means of scanning electron microscopy. Magnetization studies revealed that all solid solutions containing the BiMnO3 component can be characterized as paramagnetic materials. It was observed that magnetization values clearly correlate with the chemical composition of powders, and the gradual increase of the BiMnO3 content resulted in noticeably higher magnetization values.



2019 ◽  
Vol 20 (8) ◽  
pp. 1910 ◽  
Author(s):  
Kabiru Musa Aujara ◽  
Buong Woei Chieng ◽  
Nor Azowa Ibrahim ◽  
Norhazlin Zainuddin ◽  
Chantara Thevy Ratnam

Gamma-ray radiation was used as a clean and easy method for turning the physicochemical properties of graphene oxide (GO) in this study. Silane functionalized-GO were synthesized by chemically grafting 3-aminopropyltriethoxysilane (APTES) and 3-glycidyloxypropyltrimethoxysilane (GPTES) onto GO surface using gamma-ray irradiation. This established non-contact process is used to create a reductive medium which is deemed simpler, purer and less harmful compared conventional chemical reduction. The resulting functionalized-GO were characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), thermogravimetric analysis (TGA), and Raman spectroscopy. The chemical interaction of silane with the GO surface was confirmed by FT-IR. X-ray diffraction reveals the change in the crystalline phases was due to surface functionalization. Surface defects of the GO due to the introduction of silane mioties was revealed by Raman spectroscopy. Thermogravimetric analysis of the functionalized-GO exhibits a multiple peaks in the temperature range of 200–650 °C which corresponds to the degradation of chemically grafted silane on the GO surface.



Author(s):  
Vânia Denise Schwade ◽  
Bárbara Tirloni

Pyrimidine-2-thione (HSpym) reacts with lead(II) thiocyanate and lead(II) bromide in N,N-dimethylformamide (DMF) to form poly[(μ-isothiocyanato-κ2 N:S)(μ4-pyrimidine-2-thiolato-κ6 N 1,S:S:S:S,N 3)lead(II)], [Pb(C4H3N2S)(NCS)] n or [Pb(Spym)(NCS)] n , (I), and the polymeric one-dimensional (1D) compound catena-poly[[μ4-bromido-di-μ-bromido-(μ-pyrimidine-2-thiolato-κ3 N 1,S:S)(μ-pyrimidine-2-thione-κ3 N 1,S:S)dilead(II)] N,N-dimethylformamide monosolvate], {[Pb2Br3(C4H3N2S)(C4H4N2S)]·C3H7NO} n or {[Pb2Br3(Spym)(HSpym)]·DMF} n , (IIa), respectively. Poly[μ4-bromido-di-μ3-bromido-(μ-pyrimidine-2-thiolato-κ3 N 1,S:S)(μ-pyrimidine-2-thione-κ3 N 1,S:S)dilead(II)], [Pb2Br3(C4H3N2S)(C4H4N2S)] n or [Pb2Br3(Spym)(HSpym)] n , (IIb), could be obtained as a mixture with (IIa) when using a lesser amount of solvent. In the crystal structures of the pseudohalide/halide PbII stable compounds, coordination of anionic and neutral HSpym has been observed. Both Spym− (in the thiolate tautomeric form) and NCS− ligands were responsible for the two-dimensional (2D) arrangement in (I). The Br− ligands establish the 1D polymeric arrangement in (IIa). Eight-coordinated metal centres have been observed in both compounds, when considering the Pb...S and Pb...Br interactions. Both compounds were characterized by FT–IR and diffuse reflectance spectroscopies, as well as by powder X-ray diffraction. Compound (IIa) and its desolvated version (IIb) represent the first structurally characterized PbII compounds containing neutral HSpym and anionic Spym− ligands. After a prolonged time in solution, (IIa) is converted to another compound due to complete deprotonation of HSpym. The structural characterization of (I) and (II) suggests HSpym as a good candidate for the removal of PbII ions from solutions containing thiocyanate or bromide ions.



2010 ◽  
Vol 658 ◽  
pp. 49-52 ◽  
Author(s):  
Wen Kun Zhu ◽  
Xue Gang Luo ◽  
An Kai Luo ◽  
Xuan Liang

Calcium carbonate with various structures and morphologies were prepared under double injection of the CaCl2 and Na2CO3 solutions with molar ratio of 1:1 at 30 °C, taking lignin as the induction agents. They were characterized by scanning electron microscopy, infrared spectroscopy thermal analysis and X-ray diffraction. The synthesis mechanism was also discussed. The results showed that calcium carbonate of different shape were obtained with the concentration of lignin at 10g/L, 20g/L and 30g/L, respectively, under 30°C while CaCl2 and Na2CO3 were kept at the same concentration of 0.5mol/L. The size of the particles was in a range between 3 and 5μm and the particles were calcites. Compared with the normal calcium carbonate, the compound has advanced thermal decomposition behavior. Fourier transform infrared spectroscopy (FT-IR) analysis revealed the presence of lignin and calcite. The electrostatic interaction of Ca2+ with lignin and the complementary of stereo-structure play important roles in the formation of Dumbbell Shaped Calcium Carbonate.



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