Furong Tao

Anti-degradation gelatin films crosslinked by active ester based on cellulose

Functionalization of microcrystalline cellulose (MCC) with EDTA dianhydride (EDTAD) was first achieved using an esterification reaction. N-Hydroxysuccinimide-activated MCC-EDTAD ester (MEN), a novel macromolecule crosslinker based on MCC, was synthesized for the modification of gelatin films. The reaction between gelatin and MEN was verified by the residual free amino test, FTIR and XRD spectra. The introduction of MEN into gelatin decreased the film degradation ratio and increased its thermal stability, flexibility, hydrophobicity, light barrier performance and water uptake ability. Additionally, SEM images proved the successful surface grafting reaction and degradation phenomenon. This unique gelatin film material with advanced properties broke the limitation of the blending method for modification of gelatin with macromolecules and broadened its application as a novel sustained-release material.

Facile fabrication of AIE/AIEE-active fluorescent nanoparticles based on barbituric for cell imaging applications

Four barbituric derivatives (1–4), were synthesized with obvious aggregation induced emission (AIE) or aggregation induced emission enhancement (AIEE) behaviors. The optical properties in different states and the mechanisms of the enhanced emission of 1–4 were investigated. We found that there were a large number of globular or blocky nanoparticles with average diameters from 229 to 394 nm in tetrahydrofuran (THF)/water solutions when the water fraction (fw) was 90%. The single crystal data of 2 and 4 reveal that multiple intermolecular interactions restrict the intramolecular motions, and promote the formation of a herringbone arrangement (4), thus permitting intense emission in the aggregate state. In addition, the frontier molecular orbital energy and band gap calculated by density functional theory (DFT) are consistent with the experimental results. Compound 4 is cell-permeable: upon entering the live cells, the dye molecules can accumulate in the lysosomes and turn on the fluorescence.

Preparation and characterization of gelatin film modified by cellulose active ester

Functionalization of microcrystalline cellulose (MCC) with 1,2,3,4-butanetetracarboxylic acid dianhydride (BTCAD) was obtained by esterification reaction. A novel macromolecule cross-linker, MCC-BTCAD-NHS (MBN), was successful prepared through amidation between N-hydroxysuccinimide (NHS) and MCC-BTCAD to modify gelatin films. The reaction between gelatin and MBN was confirmed by the residual free amino test, FTIR, elemental analysis, and XRD spectra. The results indicated that the addition of MBN into gelatin decreased the film degradation ratio and increased its thermal stability, flexibility, hydrophobicity, light barrier performance, and water adsorption ability. In addition, SEM images further proved the successful cross-linking reaction. The particular gelatin film material with excellent performance ended up the limitation of blending modification method for gelatin with natural macromolecule and extended its application in many fields.

Detection of nitroaromatic explosives by a 3D hyperbranched σ–π conjugated polymer based on a POSS scaffold

A three-dimensional hyperbranched polymer (3D-HP) with σ–π conjugated PDMPS (poly(dichloromethylphenylsilane)s) units covalently bonded to a polyhedral oligosilsesquioxane (POSS) scaffold was prepared by a one-step “thiol–ene click chemistry” reaction. Compared with POSS-based organic polymers, the 3D-HP with a flexible Si–Si chain showed enhanced solubility. This 3D hyperbranched polymer exhibited outstanding thermal stability and optimal photophysical properties. For probing nitroaromatics (NACs), the 3D-HP showed excellent sensitivity (Ksv = 2.83 × 104 M−1) against the presence of a tetrahydrofuran (THF) solution of 2,4,6-trinitrotoluene (TNT). In addition, the 3D-HP coated on glass films exposed to saturated DNT vapor exhibited a high quenching efficiency (ηEP) of the fluorescence of 3D-HP film, which was drastically suppressed (82%) for 300 s. The excellent fluorescent quenching performance of the 3D-HP can be attributed to the following points: (i) hyperbranched conjugated polymers afford multi-dimensional transport pathways for excitons migration; (ii) there exists in the polymer high electron affinity and rapid electron delocalization of σ–π conjugated polysilanes; (iii) noncovalent interactions between the electropositive δ+ Si atoms of σ–π conjugated polysilanes and N and/or O atoms of electron-deficient nitroaromatics (NACs) facilitate the adsorption of NACs. Furthermore, the bulky octathiol-POSS units in the 3D-HP can improve the permeability of the film sensor. This 3D hyperbranched σ–π conjugated polymer 3D-HP has the potential to be used to prepare sensitive, selective, and stable sensors for the detection of NACs explosives.

Evaluation of nitriloacetic acid modified cellulose film on adsorption of methylene blue

A novel composite film (MCαN) based on microcrystalline cellulose (MCC) and nitrilotriacetic acid anhydride (NTAA) was prepared via casting method for the adsorption of methylene blue (MB) from aqueous solution. FT-IR, XRD, elemental analysis and TGA analysis demonstrated the success of modification. The swelling behavior, mechanical properties and MB adsorption performance of the modified MCαN films were improved obviously. The recycling study illustrated that MC2N film could be recycled and exhibited constant adsorption performance for five successful runs. In addition, mechanism study found that adsorption behavior of the composite films was better consistent with the pseudo-second order kinetic model and the Langmuir model. All the results suggested that the MCαN films could be considered as a promising candidate for dye wastewater treatment.

Eco-friendly biorefractory films of gelatin and TEMPO-oxidized cellulose ester for food packaging application

BACKGROUND In recent years, many types of food-packaging films and composites have been prepared using gelatin because of its good film-forming ability, non-toxic nature and cost-effectiveness. However, the relatively weak thermal stability, poor mechanical properties and easily-degradable quality limit the potential application of gelatin as a practical material. Microcrystalline cellulose (MCC), which comprises one of the most abundant biomass resources, has been regarded as a safe and reliable food additive because it has the same ingredients as the cellulose in peoples daily intake. Food-packaging films with the excellent properties provided by gelatin and oxidized-cellulose represent a topic of great interest. RESULTS MCC was modified by 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO)-mediated oxidation and chosen as the base of the macromolecule cross-linker (TMN). After modification of gelatin film by TMN, the minimum amount of free -NH2 in solution was 4.8 × 10-4  mol g-1 ). The thermal property obviously increased (from 322.31 o C to 352.63 o C) and was crucial for usage in the food industry. The highest water contact value 123.09° (η = 25%) indicated a better surface hydrophobicity. The higher Eab (58.88%) and lower Em (77.16%) demonstrated that a more flexible and shatter-proof material was obtained. Water vapor uptake studies suggested increased moisture absorption and greater swelling ability. CONCLUSION The film material obtained in the present study was safe, stable, eco-friendly and biorefractory and could also be decomposed completely by the environment after disposal as a result of the properties of the ingredients gelatin and cellulose. The incorporation of a cellulosic cross-linker to gelatin-based films was an ideal choice with respect to developing a packaging for the food industry.

Preparation and properties of gelatin films incorporated with N-hydroxysuccinimide-activated end-bit binary acid

A series of novel cross-linkers, N-hydroxysuccinimide (NHS)-activated end-bit binary acid (NHS-C4, C5, C6, C8, C10, C14), were synthesised to modify gelatin films and the crosslinking effects were compared. Homogeneous films with the exception of the film crosslinked by NHS-C14 were observed and the thickness was measured using a scanning electron microscope. The section feature influenced by different film-treatment conditions was also recorded. The differential scanning calorimetry results indicated higher thermal stability. The water contact angles confirmed enhanced hydrophobicity. NHS-C6, which was used as a probe crosslinker, exhibited the best crosslinking effect that the content of the free -NH2 achieved was the lowest out of all the crosslinkers. The biodegradation results of gelatin films modified by NHS-C6 exhibited better degradation-resistance and excellent stability. In addition, the optimal experimental conditions were 45°C for 12 h when [NHS-C6]/[-NH2] = 2.5.

Preparation of a hyperbranched porous polymer and its sensing performance for nitroaromatics

A hyperbranched porous polymer P based on adamantane and pyrene was synthesized through the Sonogashira coupling reaction. The three-dimensional rigid molecular skeleton of adamantane makes polymer P porous. Compound M, which acts as the block moiety between two adamantane groups in polymer P, was also synthesized for the control experiment. Compared with M, the characteristics of P changed remarkably with it exhibiting different emission behaviors and performances for the detection of DNT. In saturated DNT vapor, the quenching efficiency (ηEP) of film P (82%) was remarkably superior compared with that of film M (22%). In addition, a series of films with different thicknesses and different amounts of polymer P were prepared. Results showed that the quenching efficiencies did not change with an increase in the film thickness.

Preparation and physicochemistry properties of smart edible films based on gelatin-starch nanoparticles: Preparation and physicochemistry properties of smart edible films

BACKGROUND Among the natural polymers able to form edible films, starch and gelatin (Gel) are potential sources. Corn starch is a polysaccharide widely produced around the world, and gelatin differs from other hydrocolloids as a fully digestible protein, containing nearly all the essential amino acids, except tryptophan. Based on this, with advantages such as abundance, relatively low cost, biodegradability, and edibility, studies considering alternative systems for food protection that utilize biopolymers have increased significantly in recent years. RESULTS A novel macromolecular crosslinker starch-BTCAD-NHS (starch-butanetetracarboxylic acid dianhydride-N-hydroxysuccinimide, SBN) was successfully prepared to modify gelatin film. Compared with the blank gelatin films, the resulting SBN-Gel films exhibited improved surface hydrophobicity, higher tense strength and elongation-at-break, lower Youngs modulus values, greater opacity, poorer water vapour uptake properties and better anti-degradation capacity. CONCLUSION The modified gelatin film material with advanced properties obtained in this work was safe, stable eco-friendly and biorefractory, and was an ideal choice to form packaging in the food industry. Also, the crosslinking SBN-Gel coating was effective in reducing corruption and extending the shelf life of peeled apple substantially.

Cellulose-based film modified by succinic anhydride for the controlled release of domperidone

Abstract Succinic anhydride (SAD) modified microcrystalline cellulose (MCC) films was prepared and used for the controlled release of the drug domperidone (dom). The morphology and chemical structure of the modified materials were characterized by SEM, FTIR, XRD and TG/DSC techniques. The physical properties, such as water uptake and swelling, light barrier properties, mechanical testing, in vitro degradation behavior, have been investigated. Results showed that the modified cellulose membranes exhibited good anti-UV properties, higher water uptake values, improved mechanical capacity and anti-biodegradability. In addition, the modified MCC films (MS) as the drug carrier indicated the controlled release of domperidone and the release mechanism was proposed using Korsmeyer–Peppas equation at pH 7.4. The developed drug delivery system possessed the profound significance in improving pharmacodynamics and bioavailability of drugs.