Past, present and future prospects of cotton cross-linking: New insight into nano particles

Enhancing Hydrophobicity and Oxygen Barrier of Xylan/PVOH Composite Film by 1,2,3,4-Butane Tetracarboxylic Acid Crosslinking

Hemicellulose has potential advantages in food packaging because of its abundant reserves, degradability and regeneration. However, compared with fossil-derived plastic films, hemicellulose-based films show inferior hydrophobicity and barrier properties because of their low degree of polymerization and strong hydrophilicity. Focusing on such issues, this work covers the modification of a xylan/polyvinyl alcohol (PVOH) film using 1,2,3,4-butane tetracarboxylic acid (BTCA) as esterifying agent. The thus prepared composite film was more compact owing to the esterification reaction with xylan and PVOH forming a crosslinked network structure and reducing the distance between molecular chains. The results showed that BTCA had a positive effect on the oxygen barrier, hydrophobicity and mechanical properties of the composite film. The tensile strength of the xylan/PVOH composite film with 10% BTCA content increased from 11.19 MPa to 13.99 MPa. A 20% BTCA loading resulted in an increase in the contact angle of the composite film from 87.1° to 108.2°, and a decrease in the oxygen permeability from 2.11 to 0.43 (cm³·µm)/(m²·d·kPa), corresponding to increase in the contact angle by 24% and a decrease in oxygen permeability by 80%. The overall performance enhancement indicates the potential application of such composites as food packaging.

Cellulose cross-linking with folic acid at room via diverse-based coupling reagents attaining multifunctional features

Here, cellulose was cross-linked with folic acid (FA) using tetrafluoroborate (TBTU) and carbodiimide (DIC) as coupling reagents through the pad method at room temperature. The interactions between FA and cellulose were proposed and determined with FTIR, and UV-visible also confirmed with nitrogen content. The newly formed ester peak showed the grafting of FA to the cellulose through esterification followed by cellulose cross-linking. The surface morphology of treated fabrics indicated no significant changes and also remained similar after 5 washing cycles. This had no negative impacts on the various physical and mechanical fabric features. The fabric color was changed with reasonable fastness to laundering and light. More FA showed higher N content indicating more bacterial killing for Pseudomonas aeroginosa (Psa) and Methicillin-Resistant Staphylococcus (MRSA). The reasonable viability of L929 and MCF-7 cells showed for treated fabric with FA below 5 %.

A novel polymer reactive flame retardant for the preparation of highly durable cotton fabrics

A novel polymer ammonium salt of polyethyleneimine phosphate phosphonic acid (APEMPPA) flame retardant for cotton fabrics was synthesized and characterized by nuclear magnetic resonance (NMR), in which some ammonium phosphoric acid groups were replaced by phosphate ester groups to decrease the phenomena that the ammonium ions in flame retardant would exchange with metal ions such as Ca²⁺ and Mg²⁺ in washing water to keep flame retardance well after washing. Energy dispersive X-ray (EDX), Fourier transform infrared spectroscopy (FTIR) results, and durability of treated cotton fabrics suggested that APEMPPA was grafted onto the cellulose. Limiting oxygen index (LOI) of 40 wt% APEMPPA-treated cotton fabric was 44.5 %, which was still 34.7 % after 50 LCs according to AATCC 61-2013 3A standard. Cone calorimetric and thermogravimetric (TG) results showed the treated cotton fabrics had excellent flame retardancy. TG-FTIR and Raman test results proposed that APEMPPA mainly played a condensed phase flame retardant. EDX results indicated that replacing some ammonium phosphate groups with phosphate ester groups was effective in maintaining flame retardancy during washing. All results showed that increasing the molecular weight and introducing phosphonate group in ammonium phosphorus acid flame retardant can effectively improve flame retardancy and durability. APEMPPA-treated cotton fabrics maintained good tensile strength.

Development of eco-friendly colored/multifunctionalized cellulose/polyester blended fabrics using plasma preactivation and subsequent coloration/multifunctionalization in single stage

A new green approach was developed in the present study to pre-activate and modify the cellulose/polyester blended fabrics surfaces using atmospheric plasma, as a green alternative to non-eco-friendly conventional chemical modification processes, followed by post-dyeing/functional finishing to obtain high value-added, multifunctional, protective and colored blended fabrics. The obtained results demonstrated that the imparted antibacterial and anti-UV functional properties and the increase in color strength are greatly improved owing to plasma pre-modification step. Type of plasma gas, O2− or N2−, blended substrate, cotton/polyester (C/PET) or viscose/polyester (V/PET), kind of coloring agent: pigment, basic dye or curcumin natural dye, as well as the chemical nature of functional additive: thyme oil, clove oil, lavender, tulsi, ginger, vanillin, ascorbic acid or salicylic acid, ZnO − or Al2O3− NPs have a significant impact on extent of coloration and bi-functionalization of the final products. The extent of surface modification as well degree of fixation and immobilization of the used coloring and functional agents as well as the durability to wash were confirmed by SEM & EDX analysis and washing test, respectively.

Amino-functionalized cross-linked cellulosic fabric with antibacterial, UV protection, and coloring effects using folic acid

The amino-functionalized cellulose with folic acid, via an esterification reaction between carboxylic acid of folic acid and hydroxyl groups of cellulose, can develop multifunctional products with new chemical and physical properties. Folic acid contains two carboxylic groups as well as an amine group that can be used as a coupling agent and provide suitable conditions for coupling hydroxyl-based compounds to cellulose. Also; the multi-functionalized cellulose with folic acid has no effects on the physical and mechanical properties and also has benefits such as antibacterial, UV protection, and wrinkle resistance. The FTIR-ATR and Raman analysis confirmed the amino functionalized-cellulosic fabric via an esterification reaction between cellulose and folic acid. The cell viability of L929 fibroblast (NCBI C161) and MCF-7 (NCBI C135) cancer cells indicated more effectiveness on MCF-7 cancer cells. Therefore; folic acid can be used as a biocompatible natural cross-linker to modify cellulose fabrics for apparel and medical applications.

Study on the cross-linking process of carboxylated polyaldehyde sucrose as an anti-wrinkle finishing agent for cotton fabric

Sucrose was oxidized in a two-step oxidation reaction catalyzed by 2,2,6,6-tetramethyl-1-piperidinyloxy (TEMPO)-laccase and sodium periodate (NaIO4). To generate carboxylated polyaldehyde sucrose (openSu) containing multiple aldehyde and carboxyl groups. The amount of TEMPO and laccase used, as well as the temperature and reaction time were optimized for the oxidation reaction. The successful combination of aldehyde and carboxyl groups of openSu with cellulose was achieved by changing the composition, ratio of the catalyst and the curing conditions. Thereafter, we analyzed the structural characteristics of openSu as well as the aldehyde and carboxyl group content using nuclear magnetic resonance carbon spectroscopy (13C NMR). We found that the optimal finishing conditions were a mixture of magnesium chloride and sodium hypophosphite at a mass concentration ratio of 16 g/L:4 g/L, and curing at 150 °C for 3 min followed by curing at 180 °C for 2 min. There was significant improvement in the anti-wrinkle performance of the openSu-finished fabric, with a wrinkle recovery angle of 258°, whiteness index of 72.1, and a tensile strength rate of more than 65%. We also studied the covalent crosslinking mechanism between openSu and the cotton fabrics.

High-efficiency durable flame retardant with ammonium phosphate ester and phosphine oxide groups for cotton cellulose biomacromolecule

Cotton fibers mainly consist of cellulose biological macromolecule, and its exceedingly flammable nature has severely restricted its application in the fields requiring flame retardancy. To endow cotton fabric with excellent flame retardancy and superior durability, a high-efficiency durable flame retardant (THPO-P) with ammonium phosphate ester and phosphine oxide groups was synthesized and chemically bonded to cotton fabric through padding-baking method. THPO-P showed high flame-retardant efficiency, and the add-on of 5.9% was sufficient to prepare cotton fabric with self-extinguished feature. With the add-on of 19.9%, treated fabric possessed excellent fire safety and durability. The total heat release and peak heat release rate values reduced by 77.1% and 91.8% in contrast to pristine fabric, respectively. Its LOI value still reached up to 33.4% even after 50 laundering cycles, which was far beyond the flame-retardant standard. THPO-P played flame-retardant role by restraining the release of flammable volatiles, liberating nonflammable gases and promoting the char formation during combustion. The flame-retardant treatment deteriorated the tensile strength, whiteness and softness of cotton fabric.

Locating the Reaction Site of 1,2,3,4-Butanetetracarboxylic Acid Carboxyl and Cellulose Hydroxyl in the Esterification Cross-Linking

The modification of cellulose with polycarboxylic acid is an important technology to functionalize the substrate. 1,2,3,4-Butanetetracarboxylic acid (BTCA) can significantly improve the anti-wrinkle performance of treated cotton fabrics by cross-linking with cellulose. However, the reaction site of BTCA carboxyl and the cellulose hydroxyl has not yet been clarified, which hinders the in-depth understanding about the reaction mechanism and the development of new cross-linking reagents. This study combines Fourier transform infrared and two-dimensional correlation spectroscopy to try to make it clear. Results confirmed that BTCA anhydride is an active intermediate (corresponding to the generally accepted theory) to esterify with cellulose hydroxyl, especially the O(6)-H(6) and O(2)-H(2). Cellobiose was taken as a model of cellulose to react with BTCA at variable temperatures, proving the above conclusion. In addition, the C14- or C11-containing carboxyl of BTCA showed a higher reactivity. Based on calculating reaction kinetics and thermodynamics with Gaussian 09W software, the most likely reaction route between BTCA and cellulose was as follows: BTCA → BTCA C5C14 anhydride → C14O15 ester → C14O15 ester C31C34 anhydride → C14O15C33O ester.

Enhancing the flame retardancy of lyocell fabric finished with an efficient, halogen-free flame retardant

A novel flame retardant (PNPG) containing phosphorus and nitrogen was synthesized through the reaction of neopentyl glycol, phosphoric acid and urea, and was then used for preparation of flame retardant lyocell fabric through a dip-dry-cure finishing process. The structure of the PNPG was confirmed by proton nuclear magnetic resonance spectroscopy (¹H-NMR) and Fourier transform infrared spectroscopy (FT-IR). The flame retardancy and thermal stability of the treated fabric were evaluated by a cone calorimetry test and thermogravimetric analysis (TG), which showed that the char residue of the treated fabric at 800 °C was as high as 39.7% under a nitrogen atmosphere. At the same time, the peak heat release rate (PHRR) and total heat release (THR) were significantly reduced by 92.9% and 81.2%, respectively. Obviously, the presence of flame retardant can effectively improve the thermal stability and flame retardancy of lyocell fabrics. In addition, thermogravimetric analysis combined with Fourier transform infrared spectroscopy (TG-IR), scanning electron microscopy (SEM), and Raman spectroscopy indicated that the flame retardant mechanism was consistent with the condensed phase and gas phase mechanism. The limiting oxygen index (LOI) of the treated samples could reach 39.3%, moreover, even after 20 laundering cycles (LCs), the LOI values of the samples finished at 28.3% with 120 g L⁻¹ flame retardant remaining, which confirmed the durability and high flame retardancy of the treated samples. In addition, the mechanical properties, whiteness, rigidity and flexibility of the fabrics treated with PNPG were insignificantly reduced within a more acceptable range than the original samples. In summary, the flame retardant described herein has excellent flame retardant properties and char-forming ability, and it is suitable for the preparation of flame retardant lyocell fibers.

A novel flame retardant (PNPG) containing phosphorus and nitrogen was synthesized based on neopentyl glycol, phosphoric acid and urea, and was then used for preparation of flame retardant lyocell fabric through a dip-dry-cure finishing process.

New Method to Evaluate the Crosslinking Degree of Resin Finishing Agent with Cellulose Using Kjeldahl Method and Arrhenius Formula

In anti-wrinkle finishing, the crosslinking degree of fabric is mainly determined by wrinkle recovery angle, stiffness, and viscosity, these indicators can only reflect the finishing effect from a macro perspective, which cannot reflect whether the crosslinking is sufficient, and it is difficult to quantify the crosslinking degree. In this paper, we combined the Kjeldahl method with the Arrhenius formula and proposed a method to analyze the crosslinking degree of dimethyloldihydroxyethyleneurea (two-dimensional (2D) resin) with cotton cellulose during delayed-cure finishing for the first time. The nitrogen content of completed fabrics during storage was measured by the Kjeldahl method, and the reaction rate equation of the 2D resin and cellulose under normal temperature conditions was calculated. The results show that the nitrogen content is more suitable to indicate the crosslinking degree, and the apparent activation energy was 28.271 kJ/mol and the pre-finger factor was 0.622, which indicated that the 2D resin was prone to cross-linking with cotton fabrics during storage. During long-term storage, the relative errors between the calculated and measured values of the nitrogen content were within ±5%, and the accuracy was higher than the traditional evaluation method. The stability of 2D resins during the storage of delayed-curing finishing was also analyzed through this method.

Polysaccharide nanoparticles: from fabrication to applications

The present review highlights the developments in polysaccharide nanoparticles with a particular focus on applications in biomedicine, cosmetics and food.

High temperature ATR-FTIR characterization of the interaction of polycarboxylic acids and organotrialkoxysilanes with cellulosic material

To convey novel properties to textile surface cotton-based fabrics were impregnated with solutions containing various chemical agents, such as butane-1,2,3,4-tetracarboxylic acid or hydrolyzed organotrialkoxysilanes (3-amino)propyltriethoxysilane), (3-glycidylpropyl)-trimethoxysilane, (3-triethoxysilylpropyl)succinic acid anhydride, octyltriethoxysilane, and Dynasylan F8815 (fluoroalkylfunctional water-borne oligosiloxane). The as-prepared cotton specimens were dried and cured at elevated temperatures. As the curing process can be performed at different temperatures, the impregnated and dried cotton samples were studied by means of time-dependent ATR-FTIR spectroscopy in an attempt to get a closer insight into the process mechanism. The results make evident that the butane-1,2,3,4-tetracarboxylic acid and (3-triethoxysilylpropyl)succinic acid anhydride reacts with the hydroxyl groups of the cellulose via a five-membered cyclic anhydride intermediate which is confirmed by vibration bands appearing at 1782 cm^-1 (symmetric stretching vibration of the anhydride carbonyl group) and at 1861 cm^-1 (antisymmetric stretching vibration of the anhydride carbonyl group).

Sustainable Personal Protective Clothing for Healthcare Applications: A Review

Personal protective equipment (PPE) is critical to protect healthcare workers (HCWs) from highly infectious diseases such as COVID-19. However, hospitals have been at risk of running out of the safe and effective PPE including personal protective clothing needed to treat patients with COVID-19, due to unprecedented global demand. In addition, there are only limited manufacturing facilities of such clothing available worldwide, due to a lack of available knowledge about relevant technologies, ineffective supply chains, and stringent regulatory requirements. Therefore, there remains a clear unmet need for coordinating the actions and efforts from scientists, engineers, manufacturers, suppliers, and regulatory bodies to develop and produce safe and effective protective clothing using the technologies that are locally available around the world. In this review, we discuss currently used PPE, their quality, and the associated regulatory standards. We survey the current state-of-the-art antimicrobial functional finishes on fabrics to protect the wearer against viruses and bacteria and provide an overview of protective medical fabric manufacturing techniques, their supply chains, and the environmental impacts of current single-use synthetic fiber-based protective clothing. Finally, we discuss future research directions, which include increasing efficiency, safety, and availability of personal protective clothing worldwide without conferring environmental problems.

Oxysucrose polyaldehyde: A new hydrophilic crosslinking reagent for anti-crease finishing of cotton fabrics

For the first time, oxidized sucrose (oxysucrose) was used as a hydrophilic crosslinking reagent instead of conventional anti-crease reagents for cotton fabrics. In this research, the partial oxidization of sucrose with sodium periodate generated multiple aldehydes, which acted as multifunctional cross-linkers and endowed cotton fabrics with anti-crease and hydrophilic function. The results showed that the oxysucrose-treated cotton fabrics obtained the maximum crease recovery angle of 245°, durable press rating of 3.0, and whiteness index of 82.8. Importantly, the oxysucrose-treated samples showed better hydrophilicity that overcomes the hydrophobization deficiency of anti-creased cotton fabrics treated with previously reported dimethylol dihydroxy ethylene urea (DMDHEU), glutaraldehyde (GA), and 1, 2, 3, 4,-butanetetracarboxylic acid (BTCA). The etherification reaction between the aldehyde group of oxysucrose and the hydroxyl group of cellulose was investigated and the possible crosslinking and anti-crease mechanism was proposed.

Environmentally responsive and anti-bugs textile finishes - Recent trends, challenges, and future perspectives

Bugs, such as microorganisms and insects, are present in the environment and sometimes can be health-hazardous if the living environment is not maintained following proper hygienic regulations. In the present scenario of increasing public awareness, environmental consciousness, and growing demand for easy-care, and disinfected textiles, the manufacturing of protective and easy-to-care textiles has become a key necessity of the modern world. Comfortable, clean, hygienic, antimicrobial, and insect repelling properties of textile goods are gaining the accelerating research momentum as a basic requirement to produce multifunctional textiles. These functional finishes have numerous applications such as in-home textiles, bed nets, and tenting, camping gear as well as in military uniforms. Synthetic antimicrobial and insect repellents are quite effective against insects and microscopic organisms but are slightly toxic to the human being and the environment. To overcome these problems, researchers are considering natural agents for functional finishes, but their effectiveness is less durable to textile material. Besides needful advantages, the excessive use of dyes in finishing processes heavily required washing cycles and ultimately release various types of hazardous dyes or wasteful effluents in the environment. This review reports the chemical composition and recent developments in textile finishes, particularly antimicrobial and insect repellent textile finishes. A large number of commonly used antimicrobial agents (i.e. chitosan, zwitterionic compounds, silver and silver-based compounds, titanium dioxide nanoparticles, imidazolium salts, triclosan and quaternary ammonium salts) and insect repellent textile finishes (i.e. N‑N‑diethyl‑m‑toluamide, permethrin, cypermethrin, pyrethrum, picaridin, bioallethrin, citriodiol and essential oils) have been presented. Finally, the review is wrapped up with major research gaps/challenges, concluding remarks, and future opportunities in this area of research.

Interaction of fibroblasts and induced pluripotent stem cells with poly(vinyl alcohol)-based hydrogel substrates

Induced pluripotent stem cells (iPSCs) provide a promising means of creating custom-tailored cell lines for cellular therapies. Their application in regenerative medicine, however, depends on the possibility that the maintenance and differentiation of cells and organs occur under defined conditions. One major component of stem cell culture systems is the substrate, where the cells must attach and proliferate. The present study aimed to investigate the putative cytotoxic effects of poly(vinyl alcohol) (PVA)-based matrices on the in vitro culture of mouse fetal fibroblasts. In addition, the PVA-based hydrogels were used to determine the capacity of bovine induced pluripotent stem cells (biPSCs) to adhere and proliferate on synthetic substrates. Our results show that both cell types interacted with the substrate and presented proliferation during culture. The biPSCs formed new colonies when cell suspensions were placed onto the hydrogel surface for culture. These results may represent a new characterized xeno-free clinical grade culture system to be widely applied in cell-based therapies.

Comparative Analysis of Dry and Wet Porometry Methods for Characterization of Regular and Cross-Linked Virus Removal Filter Papers

Pore-size distribution (PSD) is the most critical parameter for size-exclusion virus removal filters. Yet, different dry- and wet-state porometry methods yield different pore-size values. The goal of this work is to conduct comparative analysis of nitrogen gas sorption (NGSP), liquid-liquid and cryoporometry with differential scanning calorimetry (CP-DSC) methods with respect to characterization of regular and cross-linked virus removal filter paper based on cellulose nanofibers, i.e. the mille-feuille filter. The filters were further characterized with atomic force and scanning electron microscopy. Finally, the removal of the worst-case model virus, i.e. minute virus of mice (MVM; 20 nm, nonenveloped parvovirus) was evaluated. The results revealed that there is no difference of the obtained PSDs between the wet methods, i.e. DSC and liquid-liquid porometry (LLP), as well as no difference between the regular and cross-linked filters regardless of method. MVM filtration at different trans membrane pressure (TMP) revealed strong dependence of the virus removal capability on applied pressure. It was further observed that cross-linking filters showed enhanced virus removal, especially at lower TMP. In all, the results of this study highlight the complex nature of virus capture in size-exclusion filters.

Catalytic and ionic cross-linking actions of l-glutamate salt for the modification of cellulose by 1,2,3,4-butanetetracarboxylic acid

The sodium l-glutamate is reported as an efficient catalyst for the cross-linking between 1,2,3,4-butanetetracarboxylic acid (BTCA) and cellulose. Results presented ester absorbance of the treated fabrics strongly increased in the presence of the homemade l-glutamate salt, a mixture of l-glutamic acid (LGA) and NaOH at a specific ratio. Importantly, anti-wrinkle properties of the treated fabrics were significantly improved. Based on the relative concentration calculation, l-glutamate promoted the reaction of BTCA with cellulose by accelerating the formation of BTCA anhydrides and the esterification of anhydrides with cellulose. Besides, the improved anti-wrinkle property was partially attributed to the fact that the generated LGA reacted with cellulose and formed ionic cross-linking networks through amino groups with carboxyl groups in BTCA, which was confirmed by the Fourier transform infrared spectra and the computational calculations. Through detailed comparisons, l-glutamate catalyzed fabrics showed as good durability as sodium hypophosphite, indicating a possible alternative for phosphorus-containing catalysts.

Multi-Response Optimization of Resin Finishing by Using a Taguchi-Based Grey Relational Analysis

In this study, the influence and optimization of the factors of a non-formaldehyde resin finishing process on cotton fabric using a Taguchi-based grey relational analysis were experimentally investigated. An L₂₇ orthogonal array was selected for five parameters and three levels by applying Taguchi’s design of experiments. The Taguchi technique was coupled with a grey relational analysis to obtain a grey relational grade for evaluating multiple responses, i.e., crease recovery angle (CRA), tearing strength (TE), and whiteness index (WI). The optimum parameters (values) for resin finishing were the resin concentration (80 g·L⁻¹), the polyethylene softener (40 g·L⁻¹), the catalyst (25 g·L⁻¹), the curing temperature (140 °C), and the curing time (2 min). The goodness-of-fit of the data was validated by an analysis of variance (ANOVA). The optimized sample was characterized by Fourier-transform infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA), and scanning electron microscope (SEM) to better understand the structural details of the resin finishing process. The results showed an improved thermal stability and confirmed the presence of well deposited of resin on the optimized fabric surface.

Effects of divalent anionic catalysts on cross-linking of cellulose with 1,2,3,4-butanetetracarboxylic acid

1,2,3,4-Butanetetracarboxylic acid (BTCA) can efficiently esterify cellulose with pyrophosphoric acid (PPA) as a catalyst to remove protons of reaction intermediates. However, valence and relative concentration ratio (RCR) of catalyst anions correlating to pH of finishing bath played a critical role in the reactions. Results here indicated that wrinkle recovery angle, tensile strength retention and ester absorbance of fabrics treated at pH of 2.8 showed higher values. It was a competing reaction for BTCA molecules to esterify or depolymerize cellulose. Importantly, divalent PPA anions were more efficient than monovalent ones in catalyzing the esterification between anhydrides and cellulose, which was confirmed by FTIR results and two-dimensional correlation spectroscopy analyses and by the RCRs of PPA anions and their changing rates versus pH. Furthermore, the higher catalytic efficiency of divalent anions was proved by the selected model catalysts. Meaningfully, the fabrics treated at pH≤3.2 presented good durability.

Loading of chitosan - Nano metal oxide hybrids onto cotton/polyester fabrics to impart permanent and effective multifunctions

New and durable multifunctional properties of cotton/polyester blended fabrics were developed through loading of chitosan (Cs) and various metal oxide nanoparticles (MONPs) namely ZnO, TiO₂, and SiO₂ onto fabric surface using citric acid/Sodium hypophosphite for ester-crosslinking and creating new anchoring and binding sites, COOH groups, onto the ester-crosslinked fabrics surface. The surface morphology and the presence of active ingredients (Cs & MONPs) onto selected - coated fabric samples were analyzed by SEM images and confirmed by EDS spectrums. The influence of various finishing formulations on some performance and functional properties such as wettability, antibacterial activity, UV-protection, self-cleaning, resiliency and durability to wash were studied. The obtained results revealed that the extent of improvement in the imparted functional properties is governed by type of loaded-hybrid and follows the decreasing order: Cs-TiO₂NPs>Cs-ZnONPs>SiO₂NP_s>Cs alone, as well as kind of substrate cotton/polyester (65/35)>cotton/polyester (50/50). Moreover, after 15 washing cycles, the durability of the imparted functional properties of Cs/TiO₂NP_s - loaded substrates marginally decreased indicating the strong fixation of the hybrid components onto the ester-crosslinked substrates. The obtained bioactive multifunctional textiles can be used for producing eco-friendly protective textile materials for numerous applications.

Green and Sustainable Technology for High-Efficiency and Low-Damage Manipulation of Densely Crosslinked Proteins

A two-step technology using nontoxic and eco-friendly chemicals is developed for the durable setting of densely/highly crosslinked proteins, such as wool and hair. Currently, most technologies for morphological modification are effective only for materials from non-highly-crosslinked proteins and cellulose. Before their morphological change, only water is needed to interrupt hydrogen bonds and ionic linkages, which stabilize the relative positions of molecules in non-highly-crosslinked proteins and cellulose. However, highly crosslinked proteins contain disulfide crosslinks, which are insusceptible to water. Thus, the controlled cleavage of disulfide bonds is required for creating new morphologies of highly crosslinked protein materials, such as hair and wool. Herein, cysteine and citric acid (CA) were used for the two-step setting of highly crosslinked proteins. This recipe showed better morphological change and less mechanical loss than commercial hair styling products. A reaction between CA and keratin was proposed, and verified via NMR and Raman spectra and titration. This technology could be a prospective alternative to achieve durable hair setting, anticrease finishing of wool textiles, and other durable morphological changes needed for highly crosslinked proteins.

Multifunctional cellulose-containing fabrics using modified finishing formulations

High performance functional cellulose-containing fabrics were prepared by including ZrO–NPs, ZnO–NPs and TiO₂–NPs into traditional finishing formulations.

Anti-wrinkle and UV protective performance of cotton fabrics finished with 5-(carbonyloxy succinic)-benzene-1,2,4-tricarboxylic acid

1,2,3,4-Butane tetracarboxylic acid (BTCA) has been considered as one of the most promising crosslinking agent to replace dimethylol dihydroxy ethylene urea (DMDHEU) for anti-wrinkle finishing on cotton fabrics. However, it could cause significant strength loss of the treated fabrics. In this study, a 5-(carbonyloxy succinic)-benzene-1,2,4-tricarboxylic acid (BSTA) was synthesized and applied as an effective crosslinking agent. The results show that fabrics treated with BSTA present the same or even better anti-wrinkle properties as that with BTCA. FTIR was employed to analyze ester bond formation process on cellulose. Finishing conditions such as agent concentration, curing temperature, and bath pH were also discussed to evaluate crosslinking effect of cellulose. BSTA, as a derivative of photo-active conjugated compound, can absorb ultraviolet lights and offer ultraviolet (UV) protective property on treated materials. The treated fabrics showed excellent UV protection performance due to the addition of aromatic conjugated system on fabrics.

Cotton flame retardancy: state of the art and future perspectives

This paper reviews the most significant achievements in cotton flame retardancy merging past experience and current efforts.

Quantitative analysis of citric acid/sodium hypophosphite modified cotton by HPLC and conductometric titration

Isocratic HPLC was used in conjunction with conductometric titration to quantitatively examine the modification of cotton cellulose by citric acid (CA)/sodium hypophosphite (SHP). CA/SHP had been extensively used as a green crosslinking agent for enhancement of cellulose and other carbohydrate polymers without in-depth understanding of the mechanisms. The current study investigated all identifiable secondary polycarboxylic acids from CA decomposition in the CA/SHP-cellulose system under various curing conditions. It was found that CA decomposition was more sensitive to temperature compared with the desirable esterification reaction. Two crosslinking mechanisms, namely ester crosslinking and SHP crosslinking were responsible for the observed improvement in crease resistance of CA/SHP treated cotton fabrics. An oligomer of citraconic acid (CCA) and/or itaconic acid (IA) was identified as a possible contributor to fabric yellowing. Finally, the crease resistance of fabrics correlated strongly with CA preservation in polyol-added CA/SHP crosslinking systems. The dosage of polyol should be held below an inflexion point to keep the undesirable competition against cellulose minimum. The combination of HPLC and conductometric titration was demonstrated to be useful in studying the CA/SHP-cellulose crosslinking system. The findings have implications for better application of CA/SHP in polysaccharide modifications in general.

ZnO nano reactor on textiles and polymers: ex situ and in situ synthesis, application, and characterization

Zinc oxide consumption has increased in today's world. It is one of the most popular nanoparticles with photocatalytic activity under light illumination utilized in different industries, especially in textiles and polymers. Lately, textiles and polymers with new features have been produced through utilization of ZnO nanoparticles to create photocatalytic characteristics, UV absorption, self-cleaning, and antimicrobial properties. Various approaches have been introduced to synthesize and apply nanoparticles on the textile and polymer surfaces such as cotton, polyester, wool, and others. This review presents diverse aspects of nano zinc oxide application in textile and polymer industry and approaches used for in situ and ex situ synthesis and application of nano zinc oxide on different textiles and polymers. This also brings a brief overview on the several studies accomplished in this area.

Structure and properties of cotton fabrics treated with functionalized dialdehyde chitosan

In this research, modified cotton fabrics were prepared by pad-dry-cure technique from the aldehyde chitosan solution containing 3-aminopropyltriethoxysilane (APTES) and 1,2-ethanediamine (EDA) respectively. The structural characterization of the modified cotton fabrics was performed by attenuated total reflection ATR, scanning electron microscopy (SEM) and thermogravimetry (TG) analysis and physical mechanical properties were measured. The adsorption kinetics of modified cotton fabrics were also investigated by using the pseudo first-order and pseudo second-order kinetic model. The dyeing rate constant k1, k2 and half adsorption time t1/2 were calculated, respectively. The results show that the mechanical properties of different modified cotton fabrics were improved, and the surface color depth values (K/S), UV index UPF and anti-wrinkle properties were better than those of untreated cotton. Dyeing kinetics data at different temperatures indicate that Direct Pink 12B up-take on the modified cotton fabrics fitted to pseudo second-order kinetic model.