Total Monomer Concentration Research Articles

Antimicrobial Properties of Corn Stover Lignin Fractions Derived from Catalytic Transfer Hydrogenolysis in Supercritical Ethanol with a Ru/C Catalyst

Converting lignin to value-added products at high yields provides an avenue for making ethanol biorefineries more profitable while reducing the carbon footprint of products generally derived from petroleum. In this study, corn stover lignin was depolymerized by catalytic transfer hydrogenolysis (CTH) in supercritical ethanol with a Ru/C catalyst. The lignin-derived bio-oil was then sequentially extracted utilizing hexane, petroleum ether, chloroform, and ethyl acetate as solvents in order of less polar to polar, and the subsequent bio-oils were characterized using GPC, GC/MS, and HSQC NMR. Results show that the monomers in the bio-oil fractions contained primarily alkylated phenols, hydrogenated hydroxycinnamic acid derivatives, syringol and guaiacol-type lignins created from reductive cleavages of ether linkages, which were sequentially extracted into groups depending on the solvent polarity. The antimicrobial properties of the bio-oils were screened against Gram-positive (Bacillus subtilis, Lactobacillus amylovorus, and Staphylococcus epidermidis) and Gram-negative (Escherichia coli) bacteria and yeast (Saccharomyces cerevisiae) by examining microbial growth inhibition. Results show that CTH-derived bio-oils inhibited all tested organisms at concentrations less than 3 mg/mL. Total monomer concentration and the presence of specific monomers (i.e., syringyl propane) showed correlations to antimicrobial activity, likely due to cell death or membrane damage. This study provides insights into using sequential extraction to fractionate lignin-derived compounds and correlations between the properties of the extracted compounds and their antimicrobial activity.

Electrochemical Co-Polymerization of Neutral Red and Aniline for Electrocatalytic Hydrogen Evolution Reaction

Electrocatalytic hydrogen evolution reaction (HER) is promising to achieve conversion of renewable electricity into storable chemical energy. For practical installation of such technology, it is important to develop active and stable electrocatalysts without relying on rare metal elements. Recently, some metal-free conductive organic polymers such as poly-dopamine (PDA) and poly-guanine (PG) have been found to exhibit stably high catalytic activity towards HER1-3. Also, we have achieved polymerization of neutral red (NR) dye, which is chemically analogous to aniline and bears amino groups at a high density. Oxidative chemical vapor deposition (oCVD) or electrodepolymerization deposition (EPD) were the techniques to achieve formation of PNR. PNR exhibited a good catalytic activity for CO2 reduction reaction (CO2RR), although the one prepared by oCVD was about twice as active as that by EPD. Structural disordering of the oCVD sample was supposed to contribute to the catalysis. It is likely that there is an optimum for the balance between conductivity and the density of hydrogen bonding sites. In this study, we have studied electrochemical co-polymerization of NR and aniline to find the optimum design of the catalyst.Electro-polymerization of poly-aniline (PANI), PNR or co-polymer PANI-PNR was carried out at an F-doped tin oxide (FTO) coated conductive glass (Asahi-DU) or a carbon felt (CF, Jing Long Te Tan) substrate by potential cycling between -0.2 and +1.0V vs. Ag/AgCl in aqueous solutions containing ANI, NR or their mixtures at appropriate ratios at a total monomer concentration of 50 mM and 0.1 M H2SO4 for 50 (FTO) or 20 cycles (CF) under N2. Linear sweep voltammetry (LSV) was performed on polymer coated CF electrodes in a 0.5 M H2SO4 under N2 for evaluation of HER catalysis.PANI appeared dark green, PNR red, whereas PANI-PNR was black. These color differences already speak for successful loading of NR into PANI to achieve PANI-PNR copolymer. Cyclic voltammograms (CVs) during EPD of PANI and PNR show the characteristic redox peaks3 (Fig. 1 a, b). While redox peaks of PANI continue to grow, the reversible redox peaks of NR almost stay the same, since formation of cation radical of NR under the present acidic condition is inefficient.3 When ANI and NR are blended, however, CV that differ from those for homopolymers of PANI and PNR is obtained (Fig. 1c). Although this CV is not the exact superimpose of the two for PANI and PNR, it suggests the presence of NR in the film and its contribution to the redox behavior.HER current in LSV almost remains the same when CF is coated with PANI, indicating its disability of electrocatalysis (Fig. 1d). Although PANI should be the most conductive among the polymers we tested here, PANI does not possess hydrogen bonding amino groups. PNR only showed moderate catalysis partly due to the small film thickness we could achieve under the current preparation condition. The PANI-PNR copolymer indeed exhibited very high catalytic activity to reduce the overvoltage as small as 250 mV. It is likely that NR provides hydrogen bonding catalytic centers while PANI assures a high conductivity. Thus, a superior catalysis has been achieved by the co-polymer strategy than using the homopolymers. The optimal compositional balance between PANI and PNR should be found by further experimental elaboration.

Preparation of PP-g-(AA-MAH) Fibers Using Suspension Grafting and Melt-Blown Spinning and its Adsorption for Aniline.

This paper uses polypropylene (PP) as the matrix and acrylic acid (AA) and maleic anhydride (MAH) as functional monomers to prepare PP-g-(AA-MAH) fibers by suspension grafting and melt-blown spinning technology that are easy to industrially scale-up. The fibers can be used to adsorb aniline. Results showed that the grafting ratio reached the maximum of 12.47%. The corresponding optimal conditions were grafting time of 3 h, AA: MAH = 0.75, total monomer content of 55%, benzoyl peroxide 1.4%, xylene concentration of 6 mL/g PP, and deionized water content of 8 mL/g PP. Owing to its good fluidity and thermal stability, the product of suspension grafting can be used for melt-blown spinning. Infrared spectroscopic and nuclear magnetic resonance spectroscopic analyses indicated that AA and MAH were successfully grafted onto PP fibers. After grafting, the hydrophilicity of PP-g-(AA-MAH) fiber increased. Therefore, it had higher absorptivity for aniline and the adsorption capacity could reach 42.2 mg/g at 45 min and pH = 7. Moreover, the PP-g-(AA-MAH) fibers showed good regeneration performance.

A two-step biopolymer nucleation model shows a nonequilibrium critical point.

Biopolymer self-assembly pathways are complicated by the ability of their monomeric subunits to adopt different conformational states. This means nucleation often involves a two-step mechanism where the monomers first condense to form a metastable intermediate, which then converts to a stable polymer by conformational rearrangement of constituent monomers. Nucleation intermediates play a causative role in amyloid diseases such as Alzheimer's and Parkinson's. While existing mathematical models neglect the conversion dynamics, experiments show that conversion events frequently occur on comparable timescales to the condensation of intermediates and growth of mature polymers and thus cannot be ignored. We present a model that explicitly accounts for simultaneous assembly and conversion. To describe conversion, we propose an experimentally motivated initiation-propagation mechanism in which the stable phase arises locally within the intermediate and then spreads by nearest-neighbor interactions, in a manner analogous to one-dimensional Glauber dynamics. Our analysis shows that the competing timescales of assembly and conversion result in a nonequilibrium critical point, separating a regime where intermediates are kinetically unstable from one where conformationally mixed intermediates accumulate. This strongly affects the accumulation rate of the stable biopolymer phase. Our model is uniquely able to explain experimental phenomena such as the formation of mixed intermediates and abrupt changes in the scaling exponent γ, which relates the total monomer concentration to the accumulation rate of the stable phase. This provides a first step toward a general model of two-step biopolymer nucleation, which can quantitatively predict the concentration and composition of biologically crucial intermediates.

Rapid UV-radiation synthesis of polyacrylate cryogel oil-sorbents with adaptable structure and performance

Macro-porous poly(lauryl acrylate) cryogel sheets as oil-sorbents were prepared through UV-radiation cryo-polymerizations in 1, 4-dioxane at low temperatures (−5, −2 and 0 °C) within 30 min. The influences of total monomer concentration, crosslinking monomer amount and polymerization temperature on the formation of cryogels were studied. The chemical structure and porous morphology were characterized through the techniques of Fourier transform infrared spectroscopy, thermal gravimetric analysis, contact angle measurement and scanning electron microscopy, confirming the features of high hydrophobicity, macro-porosity and good thermal stability. As well, the comparison between conventional gels prepared at room temperature and cryogels at lower temperatures was made, showing the higher rate of cryo-polymerization than conventional polymerization under the same UV-radiation condition. The swelling investigation was carried out with several organic solvents and oils. Enhanced performance of oil absorption was observed for those cryogels considering the absorption capacity and absorption rate. Variation of initiator amount and acrylate monomers could also modulate the absorption capacity. Those cryogel oil-sorbents exhibited wide adaptability, good reusability and high-temperature tolerance. Thus, this rapid and low-cost fabrication opens out a novel pathway to prepare efficient oil-sorbents used in waste water treatment.

The effect of monomer and chiral dopant content on reverse-mode polymer stabilized cholesteric liquid crystal display

Liquid crystal (LC)/polymer composites have great application potential in many fields. LC/polymer composites can be classified into normal mode LC/polymer composites and reverse-mode LC/polymer composites (RLCPCs). As an important application, reverse-mode polymer stabilized cholesteric LC displays (RPSCLCDs) is widely studied. In this paper, a bifunctional monomer (BPEFDA) which has V-shaped polymerizable branched chains and a monofunctional monomer (OPPEA) has been introduced. The effects of total monomer content, ratio of different monomers and chiral dopant content on the electro-optical properties of RPSCLCDs without any surface treatment are studied. The sample with the best comprehensive performance is obtained in the experiment by optimizing the percentage of monomer and chiral dopant. Compared with the traditional RPSCLCDs with rubbed alignment layers, RPSCLCDs without any surface treatment have the simple fabrication processes, low saturation voltage, small hysteresis, and fast response speed.

Characterization of Ethylene-butene Polyethylene Copolymers by DSC and SSA

Two copolymers of M1 and M2 were studied by DSC and SSA. The SSA test was applied to characterized the distribution of methylene sequence length (MSL) in the M1 and M2 copolymers. The butene comonomer contents of M1 and M2 were 4.66 mol% and 4.83 mol%, respectively. The content of butene comonomer of M1 and M2 is low, and the distribution of MSL increases monotonously with that of MSL. The longest MSL of M1 is 195.4, and the mole fraction is 0.96%, which is higher than M2. The influence of MSL and distribution on the crystallinity and Tm is greater than that of the total monomer content, which are different with traditional opinions.

Soluble tubulin is significantly enriched at mitotic centrosomes.

During mitosis, the centrosome expands its capacity to nucleate microtubules. Understanding the mechanisms of centrosomal microtubule nucleation is, however, constrained by a lack of knowledge of the amount of soluble and polymeric tubulin at mitotic centrosomes. Here we combined light microscopy and serial-section electron tomography to measure the amount of dimeric and polymeric tubulin at mitotic centrosomes in early C. elegans embryos. We show that a C. elegans one-cell stage centrosome at metaphase contains >10,000 microtubules with a total polymer concentration of 230 µM. Centrosomes concentrate soluble α/β tubulin by about 10-fold over the cytoplasm, reaching peak values of 470 µM, giving a combined total monomer and polymer tubulin concentration at centrosomes of up to 660 µM. These findings support in vitro data suggesting that microtubule nucleation in C. elegans centrosomes is driven in part by concentrating soluble tubulin.

Macroporous Oil-Sorbents with a High Absorption Capacity and High-Temperature Tolerance Prepared through Cryo-Polymerization.

The facile preparation and admirable performance of macro-porous poly(lauryl acrylate)-based oil-sorbents for organic solvents and oils are reported in this manuscript. Cryo-polymerizations of lauryl acrylate (LA) with ethylene glycol dimethacrylate (EGDMA) as the cross-linker were carried out at temperatures below the freezing point of the polymerization mixture. The polymerization medium and pore-forming agent was 1,4-dioxane. The influences of the total monomer concentration, EGDMA content and cryo-polymerization temperature on the structure of the obtained P(LA-co-EGDMA) cryogels were investigated with the techniques of Fourier transform infrared spectroscopy, scanning electron microscopy, contact angle measurement and thermo-gravimetric analysis. Through the modulation of the crosslinking density and porosity of these cryogels, the P(LA-co-EGDMA) oil-sorbents demonstrated a high absorption capacity for organic solvents and oils, recyclability and high-temperature tolerance. The absorption capacity reached 20–21 and 16–17 g/g for toluene and gasoline oil, respectively. Those fabricated sorbents survived high temperatures up to 150 °C without any change in absorption capacity as well as porosity. Considering the convenient synthesis process and absorption performance, the present work offers a remarkable opportunity to bring polymer cryogels to practical application in waste oil clean-up.

Cationic starch-grafted-cationic polyacrylamide based graphene oxide ternary composite flocculant for the enhanced flocculation of oil sludge suspension

In this study, a novel, highly efficient and environmentally friendly ternary composites flocculant, namely, cationic starch-grafted-cationic polyacrylamide/graphene oxide (CS-g-CPAM/GO), was synthesized by ammonium persulfate initiation polymerization and condensation reaction. First, CS-g-CPAM was polymerized with cationic starch (CS), acrylamide (AM) and diallyl dimethyl ammonium chloride (DMDAAC), and CS-g-CPAM/GO was then synthesized by condensation reaction. The influence factors of graft polymerization were investigated, including total monomer concentration, initiator dosage, monomer mass ratio of mAM: mCS: mDMDAAC, post-polymerization temperature and post-polymerization time. The chemical structures and morphologies of the samples were characterized by Fourier transform-infrared spectroscopy (FT-IR), X-ray diffraction (XRD), thermo-gravimetric and differential scanning calorimetry (TG-DSC), and scanning electron microscope (SEM). The CS-g-CPAM/GO was used to flocculate the oil sludge suspension, the effects of CS-g-CPAM/GO dosage, temperature and pH value on the flocculation performance were investigated, and the flocculation mechanism of CS-g-CPAM/GO was also analyzed. The results show that CS-g-CPAM/GO has outstanding flocculation effect, and CS-g-CPAM/GO flocculates oil sludge particles by adsorption bridging and charge neutralization in acidic and alkaline conditions.

Concentration Insensitive Supramolecular Polymerization Enabled by Kinetically Interlocking Multiple-Units Strategy

Concentration Insensitive Supramolecular Polymerization Enabled by Kinetically Interlocking Multiple-Units Strategy

α-Helical Motif as Inhibitors of Toxic Amyloid-β Oligomer Generation via Highly Specific Recognition of Amyloid Surface.

SummaryAmyloid fibril surfaces can convert soluble proteins into toxic oligomers and are attractive targets for intervention of protein aggregation diseases. Thus far, molecules identified with inhibitory activity are either large proteins or flat cyclic compounds lacking in specificity. The main design difficulty is flatness of amyloid surfaces and the lack of knowledge on binding interfaces. Here, we demonstrate, for the first time, a rational design of alpha-helical peptide inhibitors targeting the amyloid-beta 40 (Aβ40) fibril surfaces, based on our in silico finding that a helical fragment of Aβ40 interacts in a unique way with side-chain arrays on the fibril surface. We strengthen the fragment's binding capability through mutations and helicity enhancement with our Terminal Aspartic acid strategy. The resulting inhibitor shows micromolar affinity for the fibril surface, effectively impedes the surface-mediated oligomerization of Aβ40, and mitigates its cytotoxicity. This work opens up an avenue to designing aggregation modulators for amyloid diseases.

Graft Copolymerization of Styrene‐Maleic Anhydride Onto Poly(Vinyl Chloride) and Its Cross‐linking by Toluene Diisocyanate: Characterization, Thermal, and Mechanical Properties

In this work, styrene‐maleic anhydride (St‐MA) copolymer was successfully grafted onto poly(vinyl chloride) (PVC) by means of chemical method in cyclohexanone medium. In this manner, the effects of various parameters such as total monomer content, monomers ratio, and initiator concentration on the grafting percentage (GP) and acid value (AV) were examined. The graft copolymers were characterized by Fourier‐transform infrared and nuclear magnetic resonance spectroscopy methods. Afterward, the cross‐linking reaction was carried out through MA hydrolysis and condensation reaction between maleic acid and produced diamines, by toluene diisocyanate (TDI) at the presence of hot water. The results showed that the GP and AV of PVC‐g‐(St‐MA) copolymers were considerably higher than those of PVC‐g‐MA and PVC‐g‐St with significant molecular weight. A gel content of 56% was attained with 1 phr TDI in PVC‐g‐(St‐MA) copolymer. The glass transition temperatures and mechanical properties of PVC‐g‐(St‐MA) samples were increased compared to pure PVC. Cross‐linked PVC‐g‐(St‐MA) showed improved mechanical properties than other samples, but the glass transition temperature of PVC backbone in this cross‐linked copolymer was disappeared due to its heavily dense structure. J. VINYL ADDIT. TECHNOL., 25:377–384, 2019. © 2019 Society of Plastics Engineers

N,N-DIMETHYLACRYLAMIDE HYDROGELS FOR CONTROLLED DRUG DELIVERY. INFLUENCE OF NETWORK STRUCTURE AND DRUG SOLUBILITY ON THE LOAD AND RELEASE MECHANISMS

The aim of the present work was to synthesize sustained-release hydrogels based on N,N-dimethylacrylamide (DMA) to study the effect of the polymer matrix structure and the solubility of drugs on the load and release mechanisms. A series of crosslinked DMA hydrogels were synthesized with different monomer concentration and crosslinker to monomer ratio by free radical aqueous solution polymerization at 37ºC using N,N-methylen-bis-acrylamide as crosslinking agent. The effect of total monomer concentration and degree of crosslinking on the water absorption, glass transition temperature values, mechanical properties, and load/release of different drugs was studied. Main results showed that: a) the structure of the network, obtained by varying the monomer and crosslinking agent concentration, is a factor that governs the chemical and physical properties of the hydrogel (water absorption, glass transition temperature, storage and loss moduli, network parameters), b) the rate and amount of drug released from swellable hydrogels depend on both the degree of hydrogel crosslinking and the water solubility of the drug. In all cases, as the concentration of the crosslinker agent increased, the swelling capacity of the hydrogels was reduced and drugs with high solubility in water were more easily released, probably due to their greater affinity for the medium.

Covalently Crosslinked Nanogels: An NMR Study of the Effect of Monomer Reactivity on Composition and Structure.

Covalently crosslinked nanogels are widely explored as drug delivery systems and sensors. Radical polymerization provides a simple, inexpensive, and broadly applicable approach for their preparation, although the random nature of the reaction requires careful study of the final chemical composition. We demonstrate how the different reactivities of the monomers influence the total degree of incorporation into the polymer matrix and the role played by the experimental parameters in maximizing polymerization efficiency. Nanogels based on N-isopropylacrylamide, N-n-propylacrylamide, and acrylamide crosslinked with N,N’-methylenebisacrylamide were included in this study, in combination with functional monomers N-acryloyl-l-proline, 2-acrylamido-2-methyl-1-propanesulfonic acid, and 4-vinyl-1H-imidazole. Total monomer concentration and initiator quantities are determining parameters for maximizing monomer conversions and chemical yields. The results show that the introduction of functional monomers, changes in the chemical structure of the polymerizable unit, and the addition of templating molecules can all have an effect on the polymerization kinetics. This can significantly impact the final composition of the matrices and their chemical structure, which in turn influence the morphology and properties of the nanogels.

Synthesis, Characterization, and Sludge Dewaterability Evaluation of the Chitosan-Based Flocculant CCPAD.

Carboxymethyl chitosan (CMCS), acrylamide, and methacryloxyethyltrimethyl ammonium chloride were used as co-monomers to produce a sludge dewatering agent carboxymethyl chitosan-graft-poly(acrylamide-methacryloxyethyltrimethyl ammonium chloride) (CCPAD) by UV-induced graft polymerization. Single-factor experiments and response surface methodology were employed to investigate and optimize the grafting rate, grafting efficiency, and intrinsic viscosity influenced by the total monomer concentration, CMCS concentration, cationic degree, pH value, and illumination time. The structure, surface morphology, and thermal stability of CCPAD were characterized by infrared spectroscopy, hydrogen nuclear magnetic resonance, X-ray diffraction, scanning electron microscopy, and differential thermal-thermogravimetry. The raw sludge with 97.9% water content was sourced from the concentrated tank of a sewage treatment plant and used in the sludge condition experiments. In addition, CCPAD was applied as the sludge conditioner to investigate the effects of cationic degree, intrinsic viscosity, and pH on the supernatant turbidity, moisture content, specific resistance to filtration, and sludge settling ratio. Moreover, the mechanism of sludge conditioning by CCPAD was discussed by examining the zeta potential and extracellular polymeric substance (EPS) content of the supernatant. The sludge dewatering results confirmed that CCPAD had excellent performance for improving sludge dewaterability.

Synthesis of cationic polyacrylamide via inverse emulsion polymerization method for the application in water treatment

In order to improve the flocculent efficiency of wastewater treatment, a cationic flocculant poly (acrylamide-[2-(methacryloyloxy) ethyl] trimethyl ammonium chloride) (P (AM-DMC)) (CPAM) has been synthesized successfully via an inverse emulsion polymerization. Acrylamide (AM) and [2-(methacryloyloxy) ethyl] trimethyl ammonium chloride (DMC) were served as monomers. The molecular structure of CPAM was characterized by Fourier transform infrared spectra (FT-IR) and 1H nuclear magnetic resonance spectrum (1H-NMR). The morphology of CPAM particles has been investigated by transmission electron microscope (TEM). Results showed that CPAM was the copolymer of AM and DMC and the particles of CPAM were uniform spheres (the size was about 200 nm). The synthetic conditions of CPAM have been studied and optimized by single-factor experiments. An optimized product was obtained at an intrinsic viscosity of 560 mL/g with a total monomer concentration of 25% and initiator concentration V50 of 0.2% (based on the total monomer mass). The amount of emulsion was 6% and the HLB (Hydrophile-Lipophile-Balance) of emulsion was 7.3. In addition, the flocculation property of CPAM was evaluated with kaolin suspension using jar test, and the result demonstrated that the flocculation property of CPAM performed better than kaolin flocculation.

Preparation and evaluation of a green solvent-based molecularly imprinted monolithic column for the recognition of proteins by high-performance liquid chromatography.

A protein-based molecularly imprinted monolithic column was synthesized based on ionic liquids (ILs) and deep eutectic solvents (DESs) in a stainless steel column (50 mm × 4.6 mm id). An IL (1-allyl-3-butylimidazolium Br) and acrylamide were used as dual monomers. Another type of IL (1,2-bis [N,N'-vinylimidazolium] ethane bis Br) and N,N'-methylenebisacrylamide were used as dual cross-linking agents, and the DES (choline chloride : ethylene glycol 1 : 2) was used as a porogen in the preparation of a monolithic polymer. Bovine serum albumin (BSA) and lysozyme (Lyz), which differ greatly in molecular size, isoelectric point, and charge, were selected for imprinting templates to evaluate the recognition property of the green solvent-based MIP monolithic column. Some important factors, such as template-monomer molar ratio, total monomer concentration, and cross-linking density, were investigated systematically. Under optimal conditions, the MIP monolithic column obtained showed higher binding affinity for the templates than its corresponding non-imprinted (NIP) monolithic column.

Association Equilibrium and Gelation in Solutions of Cross-Associating Chains Containing Inactive Fragments

Solutions of two cross-associating chain molecular species (n-chains and p-chains) containing both associative (“sticky”) and non-associative monomer links have been simulated by molecular dynamics. The inactive monomers increase the stickers’ association equilibrium constant due to the excluded volume effect. In a wide concentration range, the equilibrium constant can be approximated as a simple function of the total volume concentration of the inert monomers, the volume effectively excluded by one inert monomer being about the same at different mixture compositions. Characteristics of molecular aggregates formed at pre-gelation and gelation conditions are examined, including effects of local cyclization.

Ammonium persulfate-initiated polymerization of cationic starch-grafted-cationic polyacrylamide flocculant for the enhanced flocculation of oil sludge suspension

In this study, a novel, highly efficient and environmentally friendly flocculant, namely, cationic starch-grafted-cationic polyacrylamide (CS-g-CPAM), was synthesized by initiation polymerization of ammonium persulfate. First, CS-g-CPAM was polymerized with cationic starch(CS), acrylamide(AM) and diallyl dimethyl ammonium chloride (DMDAAC), and then the influence factors of graft polymerization were investigated, including total monomer concentration, initiator dosage, the monomer mass ratio of mAM: mCS: mDMDAAC, post-polymerization temperature and post-polymerization time. And the intrinsic viscosity of the CS-g-CPAM was measured by the one point method accurately. The chemical structures and morphology of the samples were characterized by Fourier transform-infrared spectroscopy (FT-IR), X-ray diffraction (XRD), thermo-gravimetric and differential scanning calorimetry (TG-DSC), and scanning electron microscope (SEM). The CS-g-CPAM was utilized to flocculate the oil sludge suspension, the effects of CS-g-CPAM dosage, temperature and pH value on the flocculation performance were investigated. The results show that CS-g-CPAM has outstanding flocculation effect.