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In this study, an activated peroxide system was established for low-temperature bleaching of cotton by incorporating N-[4-(triethylammoniomethyl)benzoyl]caprolactam chloride (TBCC), hydrogen peroxide (H2O2) and sodium bicarbonate (NaHCO3) into an aqueous solution. The bleaching performance was modelled by response surface methodology based on a central composite rotatable design of experiment, in which concentration of TBCC ([TBCC]), concentration of NaHCO3 ([NaHCO 3]), temperature (T) and time (t) were four independent variables, and the degree of whiteness (DoW) of bleached cotton was measured as the response variable. For each individual bleaching experiment, TBCC and H2O2 were used in a molar ratio of 1:1.1 and NaHCO3 in a molar amount greater than that of H2O2 for the purpose of driving reactions to completion. A reduced quadratic model (RQM) was constructed using regression analysis with backward elimination, which was used to conduct a practical low-temperature bleaching process for cotton. In comparison to the typical conventional peroxide system, the TBCC-activated peroxide system based on the RQM predication provided cotton with an equivalent DoW and slightly inferior water absorbency, resulted in no apparent damage to cotton fibers, but worked under much milder conditions. This study provides useful insights into scaling up the TBCC-activated peroxide system for low-temperature bleaching of cotton.

Cotton fabrics with sophisticated surface-specific properties were obtained by grafting poly(tert-butyl acrylate) (PtBA), poly(acrylic acid) (PAA), poly(oligo(ethylene oxide) monomethyl ether methacrylate) (POEOMA), poly(N,Ndimethylaminoethyl methacrylate) (PDMAEMA) and quaternized PDMAEMA (QPDMAEMA) bushes on cotton surfaces using surface-initiated activators regenerated by electron transfer atom transfer radical polymerization (SI-ARGET ATRP) of three rather different monomers in a water-ethanol solvent. Due to the different physical properties and chemical composition of grafted polymers, the properties of such obtained cotton fabrics can be tailored including mechanical properties from enhanced tensile strength to increased breaking elongation, hydrophilic/hydrophobic characteristics from superhydrophilic to hydrophobic, varied water absorption abilities, different dye adsorption capabilities and charge properties. This work presents a high potential surface modification route towards functional textiles which are expected to play an important role in the future applications.

A screening experiment was designed to investigate the possible factors affecting the performance of activated peroxide systems (APSs) on bleaching of cotton fabric. The design of experiment comprised thirteen factors such as type of bleach activator (BA), concentration of bleach activator ([BA]), molar ratio of hydrogen peroxide to bleach activator ([H2O2]:[BA]), type of peroxide stabilizer (PS), concentration of peroxide stabilizer ([PS]), type of wetting agent (WA), concentration of wetting agent ([WA]), pH value of bleach bath (pH), bleaching temperature (T), bleaching time (t), liquor-to-goods ratio, cotton substrate (C), and water quality (W). The bleaching performance of APSs was accessed by measuring the degree of whiteness of bleached cotton fabric which was defined as the response factor for statistical analysis. The screening analysis revealed that C was the most significant factor affecting the performance of APSs on bleaching of cotton fabric, followed by T, BA, [BA], pH, PS, and [H2O2]:[BA]. Additionally, two-factor interactions were found as well between C and T, T and pH, C and BA, C and [BA], T and [BA], W and [PS], C and PS, and pH and [H2O2]:[BA]. These significant main effects and two-factor interactions were interpreted in details for a better understanding of the performance of APSs on bleaching of cotton fabric. The findings of this study are valuable for further establishment and optimization of APSs for low-temperature bleaching of cotton fabric.

In this paper, a series of C-terminal modified analogs of endomorphin-2 is investigated using ESI-FT-ICR-MS. Some b, y″, a, and internal ions are found in the CID spectra and slight mass differences between the calculated and observed results are obtained. Moreover, if the C-terminal modified group is t-butyloxy, it can lose butene through McLafferty rearrangement. FT-ICR MS shows its power in peptide sequencing successfully helping us obtain the structure of peptide analogs.