Dye Salt Research Articles

Thin-film composite polyester nanofiltration membrane with high flux and efficient dye/salts separation fabricated from precise molecular sieving structure of β-cyclodextrin

The treatment of dye pollutant and salts by nanofiltration membrane technology usually has the difficulty of low permeability and higher pressure in the case of maintaining a high rejection. In this study, high flux polyester membranes of β-cyclodextrin/trimesoyl chloride - multiwalled carbon nanotubes (β-CD/TMC-MWCNTs) were fabricated on a modified multiwalled carbon nanotubes (MWCNTs) substrate via interfacial polymerization (IP) process. The modified MWCNTs substrate was not only beneficial to modulating the permeation and distribution of aqueous phase monomer (β-cyclodextrin, β-CD), but also in favor of the formation of an ultrathin loose selective polyester active layer due to the porous network structure. The optimization experiments about the reaction time and monomer concentrations were conducted. The experimental results showed that the pure water flux of the as-prepared β-CD/TMC-MWCNTs membrane was 179.93 L m-2h-1 bar-1 (at the pressure of 0.1 MPa) when the reaction time of IP process was 5 min. The single dye removal efficiency of β-CD/TMC-MWCNTs membrane was 97.41% for Brilliant Green (BG) and 96.39% for Congo red (CR), respectively. The removal efficiency of dye/salt mixture by the membrane was above 84% for BG and over 98% for CR, respectively. The results indicated that the membrane had the efficient selective separation performance for the dye/salt mixture benefiting from the special molecular sieving architectures with the precisely intrinsic inner cavity of β-CD/TMC-MWCNTs membrane. Furthermore, the reusability, chlorine resistance, and antifouling ability of the β-CD/TMC-MWCNTs membrane was relatively excellent, and the membrane could effectively remove BG (>93%) and CR (>98%) simultaneously for mixed BG/CR dyes in real water body. These results suggested that the as-prepared β-CD/TMC-MWCNTs membrane had the potential of practical application in dye wastewater treatment.

Eco-friendly degradative decolourisation and detoxification of azo dye Amido Black 10B by Bacillus sp. strain AK1

ABSTRACT In this study, an azo dye Amido Black 10B was decolourised and degraded by using bacterium Bacillus sp. strain AK1. The strain decolourised 96% of the dye in 30 h at 100 mg L−1 dye concentration. Decolourisation under different sets of conditions, such as increasing dye concentration (100–600 mg L−1), pH (5–11), temperature (25–55°C) and salt levels (10–40 g L−1), was studied and found that the strain could decolourise up to 600 mg L−1 of the dye by about 54% in 72 h at pH 7 and 35°C. The bacterium also exhibited the ability to act under varied pH from 5 to 11, temperature from 25°C to 55°C and salt levels of up to 30 g L−1. The azoreductase enzyme responsible for the breaking of azo bond exhibited the activity of 1.5371 µM min−1 mg−1 protein. The products of dye degradation were identified by using UV–Visible spectroscopy and HPLC. The decolourisation also resulted in a decline in toxicity, as indicated by phytotoxicity assessment. There was also a corresponding decrease in the BOD and COD of the decolourised sample by more than 85%, which indicates the reduction in the pollution loads after decolourisation.

Electrically conductive membranes for contemporaneous dye rejection and degradation

Ultrafiltration (UF) and nanofiltration (NF) membranes have attracted great research interest to treat dye wastewaters. However, UF membranes suffer from low dye rejection and NF membranes have low salt recovery. There is a tradeoff between the dye rejection and salt recovery in the UF and NF membranes. A novel membrane is required for dye rejection with high salt recovery. Herein, we report a novel UF conductive ceramic membrane made from nano-zeolite and carbon nanostructures (CNS) combined with an external electric potential to treat crystal violet (CV) dye/NaCl-Na2SO4 salt solution. The membrane showed trimodal hierarchical porosity, a water contact angle of ≈40°, good flexibility and high electrical conductivity. Voltages from 2 to 15 V were applied to the membrane acting as a cathode in a cross-flow filtration setup. High dye rejections ≈100% with a flux of 210 LMH at a voltage as low as 3 V were achieved. Contemporaneous dye degradation was observed with several intermediate compounds, identified through mass spectroscopy. It was observed that higher potentials produced nitrates/nitrites from organic intermediates as deduced from ion chromatography results. Donnan steric repulsion increased with higher potentials, leading to increased ion transfer resistance for anions and improved permeation for cations. Various permeate properties such as pH and conductivity were monitored, along with high salt recoveries, hence providing a huge advantage of using such a membrane for treating dye wastewaters with selective dye/salt rejection. The versatile properties, together with its facile fabrication process indicates tremendous prospect of zeolite/CNS membranes for multipurpose applications treating wastewaters containing charged molecules and ions.

Spray drift deposition comparison of fluorimetry and analytical confirmation techniques.

Tracer dyes are often used as surrogates to characterize pesticide spray drift and it is assumed that they accurately reflect analytical measurement of active ingredients; however, the validity of this assumption remains inconclusive. Consequently, the influence of measurement technique on the magnitude of deposition of spray drift was investigated using spray drift samples evaluated by traditional analytical techniques (HPLC-MS/MS) and fluorimetry (1,3,6,8-pyrene-tetra sulfonic acid tetrasodium salt dye tracer). The experiment was conducted in a low-speed wind tunnel under controlled meteorological conditions. The herbicide mesotrione was sprayed through three spray air induction nozzles (anvil deflector flat fan TTI11004; flat fan AI11004; flat fan AIXR11003). Spray drift deposition samples were collected using stainless steel discs pairs placed side by side in the center of the wind tunnel at distances of 5, 10, 20, 30, and 40 ft (1.5, 3.1, 6.1, 9.1, and 12.2m) from the spray nozzle. The analytical technique determined pesticide concentration on one disc per pair, and the other was evaluated by fluorimetry. The experimental results, analyzed using the linear split-split plot model, revealed that median deposition concentrations were 15% higher using the tracer dye fluorescence method relative to the analytical method, potentially due in part to procedural recovery inefficiencies of the analytical method (the mean overall procedural recovery result and RSD was 87% ± 6.4% (n=12). This relationship was consistent and held true for the three nozzle types at all distances within the wind tunnel. © 2021 Society of Chemical Industry.

Conjugated polymers with anionic dyes: Synthesis, properties, and sensing ability for nucleosides, DNA, and BSA

AbstractThe reaction of N‐(2,4‐dinitrophenyl)pyridinium chloride (salt[Cl−]) with sodium salts of anionic dyes, such as acid red 52 (AR52), acid violet 49 (AV49), and coomassie brilliant blue G‐250 (CBBG250) involves an anion exchange between the chloride anion of salt(Cl−) and sulfonium anion of the dyes, resulting in the generation of novel Zincke salts, namely, salt(AR52), salt(AV49), and salt(CBBG250), respectively. Reactions of salt(AR52), salt(AV49), and salt(CBBG250) with piperazine in the absence of catalysts resulted in the opening of the pyridinium ring to yield ionic polymers comprising units of 5‐piperazinium‐2,4‐dienylideneammonium and the corresponding dye anion, namely polymer(AR52), polymer(AV49), and polymer(SBBG250), respectively. The corresponding model compounds for the polymers were also synthesized by reacting salt(AR52), salt(AV49), and salt(CBBG250) with piperidine. Polymer(AV49) and polymer(SBBG250) were found to be suitable for the detection of nucleosides, DNA, and proteins, realized by monitoring the changes in their UV–vis absorption spectra, arising from the anionic dyes within the polymers. The polymers and the model compounds were electrochemically oxidized in solution.

Polyphenylsulfone membrane modified by novel dendritic fibrous nanosilica (KCC-1-nPr-NH-AcCys) toward water treatment

In this work, a new type of dendritic fibrous nanosilica (DFNS) was synthesized by anchoring of N-acetylcysteine on its surface. Then, polyphenylsulfone nanocomposite membranes were prepared by phase inversion method in the presence of different amount of functionalized dendritic fibrous nanosilica (KCC-1-nPr-NH-AcCys) for water treatment. The morphological and the characteristic properties of prepared nanoparticles and the modified membrane were investigated by FT-IR, SEM, EDX, BET-BJH, pure water flux, water uptake analysis, and contact angle (CA) measurements. The obtained surface area, pore volume, and the mean pore volume for functionalized material (KCC-1-nPr-NH-AcCys) were 87.5 m2 g−1, 1.1 cm3 g−1 and 4.79 nm, respectively. Also, membrane performance was evaluated in the presence of some heavy metals (Pb2+, Co2+, Ni2+), salts (Na+, Mg2+), and malachite green dye as solution contaminants. The results showed that the applied nanomaterials in the fabrication of membrane not only generate a high surface area but also improve the membrane properties such as its hydrophilicity and pure water flux (between 5.7 Kg m−2 h−1 to 282.98 Kg m−2 h−1 for 0–7 wt%, respectively). Obtained results showed that the membranes (with 3 wt% and 5 wt% of dendritic fibrous nanosilica have the best performance in heavy metal and dye removal and salt rejection and pure water flux.

Durable and chemical resistant ultra-permeable nanofiltration membrane for the separation of textile wastewater

It is highly challenging to prepare durable and chemical resistant ultra-permeable membranes that can quickly separate small organic molecules like dye or inorganic salt in the complex textile wastewater industry. Here, side-chain sulfonated poly(ether ether ketone) (SPEEK) was synthesized and prepared the poly(ether ether ketone) (PEEK) - SPEEK nanofiltration (NF) membrane by a simple dipping coating and heat treatment. Single component filtration tests of the optimized membrane showed ultrahigh pure water flux (126 Lm−2 h−1 bar−1) and relatively low NaCl rejection (6.7%). Moreover, the negatively charged membrane exhibited excellent rejection of 98.8% toward Congo red (CR). The pure water flux was about 9 folds than that of commercial NF270 with comparable solutes rejection. The separation tests of CR and NaCl mixed solution at optimized conditions exhibited ultra-high permeation flux (34 Lm−2 h−1 bar−1), satisfactory dye (98.8%)/salt (< 10%) rejection and the separation performance remained stable after 10 cycles. Finally, the contaminated membrane was washed with ethanol, the permeation flux and the CR rejection remained constant after several cycles, while the commercial NF1 membrane exhibited serious swelling only within one cycle. The prepared membrane exhibited good organic solvents resistance and antifouling properties. Thus, this work confirmed the PEEK-SPEEK NF membrane showed great potential in the sustainable treatment of textile wastewater.

Red-sensitive organic nanoparticle-polymer composite materials for volume holographic gratings with large refractive index modulation amplitudes

We demonstrate volume holographic recording at a wavelength of 640 nm in a photopolymerizable nanoparticle-polymer composite (NPC) film dispersed with ultrahigh refractive index hyperbranched-polymer (HBP) organic nanoparticles. We employ a new photosensitizer-initiator system consisting of cyanine dye, triazine compound and borate salt for efficient radical generation in the red. We investigate the electron transfer and radical generation processes of the system by measuring fluorescence quenching and photopolymerization dynamics to find the optimum composition of the system for volume holographic recording. We show that recorded volume gratings of 0.5-µm spacing possess the saturated peak-to-mean refractive index modulation amplitudes as large as 3×10−2 at a readout wavelength of 640 nm. Our results show the usefulness of photopolymerizable HBP-dispersed NPCs for volume holographic recording materials for various photonic applications including security and color holograms, and volume Bragg grating devices in head-mounted displays.

High-Throughput Zwitterion-Modified MoS2 Membranes: Preparation and Application in Dye Desalination.

Although loose nanofiltration membranes have been extensively studied for dye desalination, high-throughput membranes with antifouling and antibacterial properties are still highly needed. In this study, a zwitterion-modified molybdenum disulfide (MoS2) dual-layer loose nanofiltration membrane was prepared with the integration of antibacterial, antifouling, and high-flux properties. To be specific, MoS2 nanosheets were loaded on a polyacrylonitrile ultrafiltration membrane through pressure-assisted self-assembly. Then, poly (sulfobetaine methacrylate) (PSBMA) was coated on the surface of the MoS2 membrane via a simple polydopamine (PDA)-assisted one-step codeposition to prepare PSBMA/PDA/MoS2 nanofiltration membranes. Elemental and morphological analyses confirmed the formation of the MoS2 layer and PSBMA/PDA coating. In addition, the effect of the PSBMA amount and codeposition time on surface properties and membrane performances was investigated. Under optimum conditions, the as-prepared membrane showed excellent water permeance of 262 LMH/bar with good dye rejection (99.8% for methylene blue) and salt permeability, as well as excellent antifouling and antibacterial properties benefiting from the synergy of PSBMA/PDA coating layers and MoS2 layers.

Effect of Reactive Dye Structures and Substituents on Cellulose Fabric Dyeing

Traditional dyeing of cotton fabrics with reactive dyes has produced many environmental problems. Therefore, it is important to investigate the relationship between dye molecular structures and dyeing properties for cleaner procedures. Here, the properties of five azo-based reactive dyes with different substituents and reactive groups were studied. The dyes had similar molecular shapes, sizes, and chromophore structures. Differences were in the aromatic rings, the number of sulfonate groups, and the position of vinyl sulfonate on the benzene ring. The dye substantivity (S%), exhaustion (E%), reactivity (R%), fixation (F%), color strength, salt effects, alkali effects, and color fastness were investigated and analyzed. Different substituents on the dyes had a little effect on the ultraviolet-visible absorption maximum wavelength. In addition, the requirements of salt and alkali to produce the maximum color strength varied for different dye structures. The dye containing a naphthalene ring, three sulfonate groups, and a vinyl sulfonate at the para-position of the benzene ring produced the highest color strength and fixation values. Color fastness was almost the same for each dyed sample, except for the wet-rubbing fastness. The results should be useful for developing new dyes and environmentally friendly dyeing techniques.

Modification of epoxy groups of poly(hydroxylmethyl methacrylate-co-glycidyl methacrylate) cryogel with H3PO4 as adsorbent for removal of hazardous pollutants.

Poly(hydroxylmethyl methacrylate-co-glycidyl methacrylate) (p(HEMA-GMA)) macroporous cryogel with high density of epoxy groups was synthesized, and the epoxy groups of the cryogel were modified into phosphonate groups. The effects of dye concentrations, adsorption time, pH, salt concentration, and adsorption temperature on the adsorption of Direct Blue-53 (DB-53) and Reactive Blue-160 (RB-160) dyes were studied. The maximum adsorption capacity was found to be 245.3 and 155.8 mg/g (0.255 or 0.119 mmol/g) for the DB-53 and RB-160 dyes, respectively. The higher adsorption capacity achieved for the DB-53 compared with the RB-160 dye can result from the pendant primary amino groups of the DB-53 dye as well as the smaller size of the dye molecule. The Langmuir isotherm model and the pseudo-second-order kinetic model well described the experimental data. The p(HEMA-GMA)-PO42- adsorbent has many operational advantages for the removal of pollutants. It could be a promising adsorbent to be used in industrial wastewater treatment.

Layer-by-layer assembled GO-based membranes with high long-standing stability and chemical resistance applied in dye separation and desalination

The Graphene oxide (GO) membranes, as the most studied and accessible two-dimensional (2D) membranes, have performed their expected separation performance, but instability of these delicate membranes still hinders their development. Layer-by-layer (LBL) self-assembly is one smart method for preparing versatile 2D membranes with stable structure by chemical bonds or other forces. Herein, the 2D GO laminar membranes were prepared on the modified Nylon-6 substrates via LBL method by employing positively charged P–GO (guanidine modified GO nanosheets) and negatively charged S–GO (sulfonated GO nanosheets) as assembly flakes. This smart strategy was established on the superiority of LBL method by adjusting the assembly layer number and outermost charge when faced up with the different targeted contaminants. Benefited from the compact structures and intense charge, the LBL membranes can almost remove all the employed dyes (above 98% rejection for ML11 membrane). Furthermore, these membranes also show the high selectivity to water molecular in desalination (93.4% rejection to Na2SO4 and 72.7% rejection to NaCl for ML11 membrane). The membranes can endure the filtration of dye wasterwater and salt solution for above 168 h under cross-flow mode without rejection decline. Also, these versatile LBL membranes reveal high resistance to both chemical corrosion and bacterial attack, which is suitable for the continuous separation even under hostile external environment.

Degradation and toxicity evaluation of azo dye Direct red 83:1 by an advanced oxidation process driven by pulsed light

Water contamination by dyes is an ecological problem that can be alleviated by advanced oxidation processes (AOPs). A common AOP uses hydroxyl radicals generated by splitting H2O2 using UV light. Pulsed light (PL) technology can be used as light source in AOPs having the advantage of producing fast effects. Direct red 83:1 (DR) is an azo dye that is being used to study the elimination of dyes from wastewaters but details about its degradation by a PL/H2O2 process are missed. In this work, the effect of H2O2 and dye concentrations, pH and salts on the decolourization of DR were determined by spectrophotometry. The PL/H2O2 process was able to degrade nearly 80 % of the dye after 45 light pulses. Absence of photolysis and inhibition by hydroxyl scavenging indicate that the degradation was due to oxidation hydroxyl radicals. The decolouration was higher at low dye concentration, high H2O2 concentration and alkaline conditions, and was inhibited by salts. These results are useful for the further use of DR as model dye to study the potential of PL as an alternative light source in AOPs for dye degradation. Further studies are recommended to estimate the treatment conditions required for enhancing toxicity abatement.

Highly selective separation and resource recovery using forward osmosis membrane assembled by polyphenol network

We report a novel forward osmosis (FO) membrane prepared by a green tannic acid/iron (TA/Fe) coordination chemistry to selectively separate and recover organic source from salty water. The microscopic and x-ray photoelectron spectroscopy (XPS) characterizations confirmed the formation of a thin continuous TA/Fe rejection layer with a thickness of 20–30 nm on a polyacrylonitrile (PAN) substrate. This TA/Fe-PAN membrane showed a high water permeability (A) of 14.2 ± 1.7 Lm−2h−1bar−1, a high rejection of 99.5 ± 0.1% for a low-molecular dye sunset yellow and low rejection of 27.6 ± 2.7% for NaCl under reverse osmosis (RO) mode. The membrane selectivity to sunset yellow was nearly three orders of magnitude greater than that of NaCl, revealing its preference towards organic dye retention and salt passage. As a result of its higher water permeability and the prevention of salt accumulation during FO tests, the TA/Fe-PAN membrane showed significantly higher FO water flux compared to that of a commercially available polyamide thin film composite membrane. It could concentrate sunset yellow from a salty FS solution with a concentration ratio of 9.6 and mild salt accumulation at the water recovery ratio of 90%. The results demonstrated the feasibility of selective separation and resource recovery for target solutes from salty even more complicated water matrix via proper membrane chemistry design in FO.

In Vivo Percutaneous Penetration of Dye into IgWAT and IBAT Using Dissolving Microneedle and Iontophoresis

Abstract Objectives Browning subcutaneous (subQ) white adipose tissue (WAT) or activating brown adipose tissue (BAT) is a promising approach for combating obesity and its comorbidities. Transdermal delivery of browning compounds efficiently to subQ WAT or BAT via microneedle (MN) and iontophoresis, if successful, will represent a new paradigm for treating obesity and its related metabolic disorders in a much more effective, comfortable, easy and safe regimen. The purpose of this study was to investigate the application of dissolving MN in combination with iontophoresis on the skin of mice for transdermal delivery of dye to inguinal WAT (IgWAT) or interscapular BAT (IBAT). Methods Dissolving MN was fabricated using poly (lactic-co-glycolic acid) (PLGA). C57BL/6 J mice received the following 4 treatments: 1. Control (no MN or iontophoresis), 2. MN alone, 3. Iontophoresis alone and 4. MN plus iontophoresis. The 1,1′-dioctadecyl-3,3,3′,3′- tetramethylindodicarbocyanine, 4-chlorobenzenesulfonate salt (DID) dye was loaded into the MN. Treatments were applied on the skin above IgWAT and IBAT of mice. After 24 hours, dye distribution in the body was imaged using an in vivo imaging system (IVIS). After sacrifice, the IgWAT, IBAT, liver, kidneys, lung, and heart were dissected for further analysis. The IVIS imaging system in this study was used to analyze all fluorescence data. Results The average fluorescent intensity from the treated IgWAT and IBAT area of mice was 2.04 102 and 4.16 102 fold higher in MN plus iontophoresis than MN or iontophoresis alone, respectively. The same pattern was also seen in dissected IgWAT and IBAT with 2.73 102 and 3.57 102 fold higher average fluorescent intensity in MN plus iontophoresis treatment than MN or iontophoresis alone. In summary, mice treated with MN plus iontophoresis had higher fluorescent signals in IgWAT and IBAT than the other groups of mice. No fluorescent signals were detected in other collected organs. Conclusions MN in combination with iontophoresis can synergistically enhance transdermal delivery of dye or browning agents to IgWAT and IBAT mice, which might combat obesity via enhancing subQ WAT browning or increasing BAT activity. Funding Sources NIH 1R15AT010395 and AHA 19AIREA34480011.

Large Area Self-Assembled Ultrathin Polyimine Nanofilms Formed at the Liquid-Liquid Interface Used for Molecular Separation.

Separation membranes with higher molecular weight cut-offs are needed to separate ions and small molecules from a mixed feed. The molecular sieving phenomenon can be utilized to separate smaller species with well-defined dimensions from a mixture. Here, the formation of freestanding polyimine nanofilms with thicknesses down to ≈14 nm synthesized via self-assembly of pre-synthesized imine oligomers is reported. Nanofilms are fabricated at the water-xylene interface followed by reversible condensation of polymerization according to the Pieranski theory. Polyimine nanofilm composite membranes are made via transferring the freestanding nanofilm onto ultrafiltration supports. High water permeance of 49.5 L m-2 h-1 bar-1 is achieved with a complete rejection of brilliant blue-R (BBR; molecular weight = 825 g mol-1 ) and no more than 10% rejection of monovalent and divalent salts. However, for a mixed feed of BBR dye and monovalent salt, the salt rejection is increased to ≈18%. Membranes are also capable of separating small dyes (e.g., methyl orange; MO; molecular weight = 327 g mol-1 ) from a mixed feed of BBR and MO. Considering a thickness of ≈14 nm and its separation efficiency, the present membrane has significance in separation processes.

Removal of Acid Yellow 36 and Rhodamine B from single and binary systems by reverse micelles

In the present study reverse micelles are employed to encapsulate ionic dyes such as, azo dye Acid Yellow 36 (AY36) also known as Metanil Yellow and cationic dye Rhodamine B (RhB). This method proved to be highly efficient in the removal of high concentrations of dyes as much as 40mg/100ml from aqueous solutions of single and binary systems. The effect of different parameters like initial dye concentration, surfactant concentration, pH and salt (KCl) concentration on the percentage removal of the dyes were studied. It was observed that the percentage removal for both anionic and cationic dye decreased with the increase in the initial dye concentration and increased with the increase in the surfactant concentration in case of both the dyes in single and binary systems. Further, it was noticed that for anionic dye the percentage removal increased with the increase of both pH and KCl concentration while the results were exactly the reverse in case of RhB dye which exists in both cationic and zwitterionic forms at pH above 4. In binary systems, it was found that the removal of RhB increased compared to its removal from single system, while the removal of AY36 decreased in binary system

Preparation of molecular selective GO/DTiO2-PDA-PEI composite nanofiltration membrane for highly pure dye separation

The state-of-the-art graphene oxide (GO) has been wildly used in water purification due to its tunable nanoscale interlayer between the two-dimensional nanosheets. However, the structural instability and flux decline performances significantly limit the practical application of GO-based membranes. Herein, a novel GO/DTiO2-PDA-PEI (dopamine modified TiO2) composite nanofiltration membrane has been prepared via a multi-coupled strategy, combining with the self-assembly, copolymerization and surface grafting. Tuning the nanoscale interspace between the GO nanosheets, and constructing the membrane with positively charged surface and negatively charged subsurface, the loose GO/DTiO2-PDA-PEI composite nanofiltration membrane (GDP1P2-0.6 membrane with a mean pore size = 0.87 nm) show the filtration performance with water permeance as high as 41.6 L m−2 h−1 bar−1 and dye rejection around 99.9%, and the molecular selective factor (Eriochrome black T/Na2SO4) of α = 47.6. Long-term performance and stimulation have been investigated to further analyze the dye concentration and salt removing. The investigations demonstrate that the GO/DTiO2-PDA-PEI composite nanofiltration membrane enriches 14.9-fold Eriochrome black T (ET) and reduces Na2SO4 to 0.36% in the term of the concentration factor 15 and batch diafiltration factor 5.

An exploration of the rapid transformation method for Dunaliella salina system

As a new expression system, Dunaliella salina (D. salina) has bright prospects and applications in various fields. However, its application is currently restricted because of the low expression and instability of foreign gene in D. salina cells. During genetic operation, transformation is a crucial step for genes expression in D. salina system. Although several transformation methods are existing currently, many inherent deficiencies and limitations still can be found in actual practice. Thus, we attempted to set up a rapid transformation method using the change of salt concentrations for D. salina. Based on osmotic pressure difference, exogenous genes can be spontaneously transferred into D. salina cells. After that, transformed D. salina cells were subjected to histochemical and molecular analysis. The results showed that the reporter gene, beta-glucuronidase genes were successfully expressed in the positive transformants, and detected in all of transformed cells by PCR analysis. Moreover, different transformation parameters, containing the salt gradient, time, dye dosage and Triton X-100 concentration, were optimized to obtain an optimal transformation result. Taken together, we preliminarily established a rapid transformation method with the features of fast, simple, economic, and high-efficient. This method will provide a strong genetic manipulation tool for the future transformation of D. salina system.

An Investigation Into the Effect of Different Parameters on the Dyeing of High-Performance M-Aramid Fiber and Its Optimization

M-aramid fibers have very good flame-retardant properties and are mostly used in protective textiles such as racing or firefighter suits. The dyeing and fastness properties of m-aramid fibers are investigated in this article in a batch process to optimize dyeing parameters such as dye concentration, salt, swelling agent, and temperature. The exhaustion at an acidic pH, preferably in the range of 4–5, indicated good results. The color yield of m-aramid fibers was found to be dependent on the concentration of swelling agent, salt, and dye, as well as the dyeing temperature. The effect of swelling agent on the K/S of m-aramid fibers with cationic dyes, along with their fastness properties, is investigated and reported in detail.