Cellulose Blend Research Articles

Preparation of N-doped carbon materials from cellulose:chitosan blends and their potential application in electrocatalytic oxygen reduction

Carbon-based electrocatalysts for oxygen reduction reaction (ORR) are prepared by a direct pathway including a two-step thermal treatment process applied to porous spheres of natural biopolymer blends. Cellulose blends with chitosan are first thermally treated at moderate temperatures (e.g., 200 °C), then pyrolyzed at elevated temperature (800–1000 °C), both steps under a constant nitrogen flow. By blending of cellulose with chitosan, the nitrogen content in the final carbon-based catalyst can be considerably increased. The influence of the composition of the precursor biopolymer blend on the ORR electrocatalytic activity is analyzed in correlation with the elemental composition and other structural features of the catalyst. The polymer blend containing cellulose:chitosan = 75:25, thermally treated 1 h at 200 °C and pyrolyzed 1 h at 800 °C under nitrogen atmosphere, shows the highest electrocatalytic ORR activity. This is attributed to an increased surface area combined with relatively high nitrogen content and a higher pyridinic/pyrrolic species ratio.

Cellulose blends from gel extrusion and compounding with polylactic acid

AbstractCellulose, dissolved in ionic liquids (IL), can be used successfully in the processing of thermoplastics. To recover the ionic liquid while maintaining the thermoplastic properties, other spacers than IL might be introduced into the cellulose network. Such blend materials have been prepared before by solution blending as reported in the literature. In this study, the preparation and investigation of cellulose and polylactic acid (PLA) blends using an extrusion process with an ionic liquid and co‐solvent for intermediate compatibilization is reported. The obtained transparent films show a homogeneous morphology without phase separation. Thermal analysis showed no separated glass transition for PLA, and FTIR showed hydrogen bonding between cellulose and PLA chains. Thermal stability of the blends with a degradation onset around 270°C lies between regenerated cellulose and pure PLA. The blend tensile strength and elongation of ~40 MPa and 1.3%, respectively, were comparable to a multiphase composite containing twice the molecular weight of PLA. Generally, mechanical performance of the blends was strongly influenced by degradation reactions mainly caused by the ionic liquid used, as well as blend morphology. The study shows that transfer from solution to extrusion processing is generally possible to obtain novel cellulose blends.

Hydrophilic Surface Modification of TFC Reverse Osmosis Membrane Using Blends of Sodium Carboxymethyl Cellulose and Chitosan

ABSTRACT The present work showed a scalable protocol for anchoring hydrophilic layer over the polyamide using biodegradable polysaccharide solutions of carboxymethyl cellulose sodium (CMC) and chitosan. CMC and chitosan were blended in different concentration ratios with and without an oxidative environment. The membrane treated with CMC: Chitosan blend demonstrated upto 153.97% and 240.47% increment in water permeance without and with oxidative environment respectively as compared to the virgin thin film composite reverse osmosis membrane. The modified membranes had shown considerable decline in contact angle from 48.37° to 35.66°, changes in surface roughness, morphology and chemical structural changes of the top surface.

Evaluation of Keratin-Cellulose Blend Fibers as Precursors for Carbon Fibers.

One main challenge to utilize cellulose-based fibers as the precursor for carbon fibers is their inherently low carbon yield. This study aims to evaluate the use of keratin in chicken feathers, a byproduct of the poultry industry generated in large quantities, as a natural charring agent to improve the yield of cellulose-derived carbon fibers. Keratin–cellulose composite fibers are prepared through direct dissolution of the pulp and feather keratin in the ionic liquid 1,5-diazabicyclo[4.3.0]non-5-enium acetate ([DBNH]OAc) and subsequent dry jet wet spinning (so-called Ioncell process). Thermogravimetric analysis reveals that there is an increase in the carbon yield by ∼53 wt % with 30 wt % keratin incorporation. This increase is comparable to the one observed for lignin–cellulose composite fibers, in which lignin acts as a carbon booster due to its higher carbon content. Keratin, however, reduces the mechanical properties of cellulose precursor fibers to a lesser extent than lignin. Keratin introduces nitrogen and induces the formation of pores in the precursor fibers and the resulting carbon fibers. Carbon materials derived from the keratin–cellulose composite fiber show potential for applications where nitrogen doping and pores or voids in the carbon are desirable, for example, for low-cost bio-based carbons for energy harvest or storage.

Fabrication of sustainable organic solvent nanofiltration membranes using cellulose–chitosan biopolymer blends

Membrane technologies have emerged as a promising alternative to energy-intensive separation processes in various industrial sectors. To address the sustainability challenge associated with the fabrication of separation membranes, a paradigm shift from the use of petrochemical-based raw materials to greener biobased sources is highly desired. In this study, blends of cellulose — as a plant-based material — and chitosan — obtained from shrimp farming waste and used as a biomass material — were investigated for the fabrication of oil and solvent-resistant nanofiltration membranes. The structural, thermal, mechanical, and morphological properties of the prepared membranes were characterized. Molecular simulations were performed to study the fractional free volume and interaction energy among membrane constituents. Adjusting the cellulose–chitosan ratio allowed fine-tuning the molecular sieving properties of the membranes, which exhibited outstanding separation performance and chemical stability even in harsh solvents, such as polar aprotic solvents, at the maximum temperature of 100 °C. Cellulose membranes containing 25 wt% chitosan achieved the lowest molecular weight cutoff value of 413 g mol−1 and a permeance of 24 L m−2 h−1 bar−1 in acetonitrile. The membranes showed stable separation performance over 7 days of continuous cross-flow nanofiltration. Moreover, the cellulose membranes blended with 10–25 wt% chitosan showed decreased water permeance from 52 to 38 L m−2 h−1 bar−1 and increased oil-removal efficiency from 73.8% to 98.6%. Furthermore, the membranes successfully underwent biodegradation, confirming their potential to close the loop of the sustainable lifecycle of membranes from cradle to grave.

Development and Characterization of Pullulan-Carboxymethyl Cellulose Blend Film for Packaging Applications

Edible packaging materials have widespread applications in pharmaceutical industries. In this study, the physical, thermal, colour, mechanical, and water barrier properties of a novel edible film based on pullulan (PUL) and carboxymethyl cellulose (CMC) were investigated. The blend films were made by the solution casting method with 3 g of total solid content. The following percentages of 100/0, 75/25, 50/50, 25/75, and 0/100 were used to prepare the films. Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), and thermogravimetric analysis (TGA) were used to analyze the interaction between PUL and CMC. At the level of 75/25 percentage of PUL, CMC film showed the lowest EAB% (5.55%), the highest values for TS (17.30 MPa), WVP value ( 4.12 × 10 − 10 g m-1s-1Pa-1), and water contact angle of 63.43°. By increasing the CMC concentration, blend films became slightly greenish and yellowish but appeared transparent with UV blocking ability. This study reveals that 75/25 (PUL/CMC) blend film has a good potential that can be used in producing edible packaging films to protect the quality of pharmaceutical products with interesting specifications.

An Insight into the Impact of Thermal Process on Dissolution Profile and Physical Characteristics of Theophylline Tablets Made through 3D Printing Compared to Conventional Methods.

The dissolution profile is of great importance in drug delivery and is affected by the manufacturing method. Thus, it is important to study the influence of the thermal process on drug release in emerging technologies such as 3D printing-fused deposition modeling (FDM). For this purpose, the characteristics of 3D printed tablets were compared to those of tablets prepared by other thermal methods such as hot-melt extrusion (HME) and non-thermal methods such as physical mixture (PM). Theophylline was used as a drug model and blends of ethyl cellulose (EC) and hydroxypropyl cellulose (HPC) were used as a matrix former. The solid state of the drug in all formulations was investigated by differential scanning calorimetry, X-ray powder diffraction, and Fourier-transformed infrared spectroscopy. All studied tablets had the same weight and surface area/volume (SA/V). Dissolution data showed that, for some formulations, printed tablets interestingly had a faster release profile despite having the highest hardness values (>550 N) compared to HME and PM tablets. Porosity investigations showed that 100% infill printed tablets had the highest porosity (~20%) compared to HME (<10%) and PM tablets (≤11%). True density records were the lowest in printed tablets (~1.22 g/m3) compared to tablets made from both HME and PM methods (~1.26 g/m3), reflecting the possible increase in polymer specific volume while printing. This increase in the volume of polymer network may accelerate water and drug diffusion from/within the matrix. Thus, it is a misconception that the 3D printing process will always retard drug release based on increased tablet hardness. Hardness, porosity, density, solid-state of the drug, SA/V, weight, and formulation components are all factors contributing to the release profile where the total balance can either slow down or accelerate the release profile.

Shifting to Transparent/Hazy Properties: The Case of Alginate/Network Cellulose All-Polysaccharide Composite Films.

Light-management films made entirely from natural polymers with tunable haze properties are developed via a facile approach. A novel green method based simply on the blending of network cellulose (NC)/water suspension with alginate (CaAlg) aqueous solution is proposed. The unique NC suspension created by a controlled hydrolysis of microcrystalline cellulose acts as the scatterer media while alginate serves as the transparent host matrix. NC features isotropic intertwined network of nanofibers that contributes to light scattering and produces optical haze. The opaque but hazy NC is dispersed purposefully in the alginate film, where its original properties are preserved owing to its poor solubility in water. Additionally, the dispersion notably increases the roughness of the composite film surface and acts as a light scatterer. Eventually, composite CaAlg/NC film with high transparency (>94%) and customized haze (15-73%) at 550 cm-1 wavelength is fabricated. Herein, the transparent alginate is successfully combined with the hazy cellulose of uniformly distributed nanofibers by blending to fabricate transparent/hazy all-natural films. The fabricated films exhibit high transparency with tailored transmission haze. The film is highly fitting for large-scale production and adequate to meet different haze requirements to accommodate different applications such as privacy protection films and antiglare/antireflection coatings.

Effect of zinc oxide nanoparticles on physical properties of carboxymethyl cellulose/ poly (ethylene oxide) matrix

Zinc oxide nanoparticles (ZnO NPs) with sizes 20–80 nm were successfully prepared using the Sol-Gel technique. They were loaded with different weight ratios (wt.%) ∼ 0, 0.3, 0.8, 2, 4, and 6 wt% on a polymer blend of carboxymethyl cellulose (CMC)/polyethylene oxide (PEO) (70:30) utilizing the solution casting route. The formed ZnO NPs loaded with CMC/PEO blend demonstrate a notable decrement in the bandgap from 4.51 to 3.34 eV. A significant increase in the refractive index from 1.79 to 1.97 was observed with increasing ZnO NPs content from 0 to 6 wt %. AC conductivity (σac) measurements at 298 K revealed a measurable enhancement in conductivity and dielectric parameters with the increase of ZnO NPs contents reaching their optimum values at 2 wt%. Furthermore, the temperature dependence of the σac and dielectric parameters was investigated for the optimum concentration, highlighting its unique characteristics for solid-state supercapacitors.

Formulation and Evaluation of Nano Lipid Carrier-Based Ocular Gel System: Optimization to Antibacterial Activity

The present research work was designed to prepare Azithromycin (AM)-loaded nano lipid carriers (NLs) for ocular delivery. NLs were prepared by the emulsification–homogenization method and further optimized by the Box Behnken design. AM-NLs were optimized using the independent constraints of homogenization speed (A), surfactant concentration (B), and lipid concentration (C) to obtain optimal NLs (AM-NLop). The selected AM-NLop was further converted into a sol-gel system using a mucoadhesive polymer blend of sodium alginate and hydroxyl propyl methyl cellulose (AM-NLopIG). The sol-gel system was further characterized for drug release, permeation, hydration, irritation, histopathology, and antibacterial activity. The prepared NLs showed nano-metric size particles (154.7 ± 7.3 to 352.2 ± 15.8 nm) with high encapsulation efficiency (48.8 ± 1.1 to 80.9 ± 2.9%). AM-NLopIG showed a more prolonged drug release (98.6 ± 4.6% in 24 h) than the eye drop (99.4 ± 5.3% in 3 h). The ex vivo permeation result depicted AM-NLopIG, AM-IG, and eye drop. AM-NLopIG exhibited significant higher AM permeation (60.7 ± 4.1%) than AM-IG (33.46 ± 3.04%) and eye drop (23.3 ± 3.7%). The corneal hydration was found to be 76.45%, which is within the standard limit. The histopathology and HET-CAM results revealed that the prepared formulation is safe for ocular use. The antibacterial study revealed enhanced activity from the AM-NLopIG.

Enhanced structural, optical, electrical properties and antibacterial activity of PEO/CMC doped ZnO nanorods for energy storage and food packaging applications

The zinc oxide nanorods (ZnONRs) have been successfully prepared via sol–gel way. A series of Poly(ethylene oxide) and Carboxymethyl cellulose (PEO/CMC) blend samples filled with different concentration of ZnONRs were prepared using casting method. Transmission electron microscopic (TEM) image showed that the synthesized ZnONPs had a diameter in the range of 29.29 to 59.09 nm. These samples were characterized by different analytical techniques. On the basis of results obtained from XRD and FT-IR analysis, blends are miscible. Fourier transform infrared (FT-IR) spectroscopy exhibited the complexation between PEO/CMC blend and ZnONRs. The optical energy gap was calculated using the UV/vis. data. The maximum value of AC conductivity for the pure blend was 1.98 × 10–7 S.cm−1, and by raising the filling of ZnONRs increased to 3.26 × 10–6 S.cm−1 at highest concentration. After the added of ZnONRs, an improvement for the dielectric constant (ε′) and dielectric loss (ɛ") of PEO/CMC are detected. These samples can be employment in the semiconductor industries and portable electrochemical batteries, electric vehicles and grid energy storage, due to the noticed enhancements in optical, and AC conductivity. PEO/CMC/ZnONRs films were screened for their in vitro antibacterial activity against S. aureus and E. coli bacteria have been tested. The excellent antimicrobial activity of these films provides a novel and simple way for the synthesis nanocomposites as functional biomaterials and has the possibility for usage in food packaging applications.

Enhancement of physico-chemical, optical, dielectric and antimicrobial properties of polyvinyl alcohol/carboxymethyl cellulose blend films by addition of silver doped hydroxyapatite nanoparticles

Hydroxyapatite nanoparticles doped with silver AgHA-NPs were synthesized successfully then added with various mass fractions to a mixed solution of polyvinyl alcohol (PVA)/ carboxymethyl cellulose (CMC) using the casting technique. Experimentally, the influence of silver doped hydroxyapatite nanoparticles on the structural, optical, dielectric and antimicrobial properties of nanocomposite films was investigated. X-ray diffraction and Fourier transformation infrared spectroscopy were used to explore the structural features of these films. The XRD analysis revealed the amorphous nature of PVA/CMC blend and the intensity of the characteristic peak of the virgin polymers in the nanocomposite spectrum being much reduced as the doping level was increased. The FT-IR spectra indicated that the blend components were miscible by revealing the functional groups of two polymers that interacted through the formation of a hydrogen bond while, the FT-IR spectra of nanocomposite confirmed the good interaction between the blend chains and AgHA-NPs. The morphological graphs of the prepared blend were formed as hexagonal grains with size distribution around 18.36–24.11 μm. The addition of AgHA-NPs changed the surface morphology of the blend significantly. The optical properties of PVA/ CMC blend and nanocomposites films were measured in the 200–800 nm wavelength range. Optical measurements showed that the optical transmittance for pure blend was nearly 90% while it decreased to 50% with increasing AgHA-NPs contents up to 40 wt.%. The energy gap values calculated by Tauc's model and those determined by ASF model are consistent, where their values reduced by AgHA-NPs incorporation. The dielectric constant of all samples were studied in range of temperatures (303–405 K) and from100 kHz to 1.0 MHz, range of frequencies. The Correlated Barrier Hopping (CBH) is the most appropriate conduction mechanism based on the frequency dependence of the ac conductivity. Silver ion release was examined showed that he film loaded with 10 wt.% AgHA-NPs has a small release of silver ion, while the amount of the Ag+ released from the samples increased slowly with increasing the content of AgHA-NPs. PVA/CMC/AgHA films were tested for antibacterial activity against both (Bacillus subtilis) and (Escherichia coli) as well as the anti-fungal activity against (Candida albicans),their results showing an increase in the activity index as the filling level of AgHA-NPs increases. The study confirmed that doping of AgHA-NPs into PVA/CMC improves both electrical conductivity and antimicrobial efficiency and these nanocomposites might be recommended for further work in biomedical applications such as wound dressing and infection control.

Photocatalytic Degradation of Textile Dye on Blended Cellulose Acetate Membranes.

This work aimed to investigate the degradation performance of natural cellulose acetate (CA) membranes filled with ZnO nanostructures. Photocatalytic degradation of reactive toxic dye methylene blue (MB) was studied as a model reaction using UV light. A CA membrane was previously casted and fabricated through the phase inversion processes and laboratory-synthesized ZnO microparticles as filler. The prepared membrane was characterized for pore size, ultrafiltration (UF) performance, porosity, morphology using scanning electron micrographs (SEM), water contact angle and catalytic degradation of MB. The prepared membrane shows a significant amount of photocatalytic oxidation under UV. The photocatalytic results under UV-light radiation in CA filled with ZnO nanoparticles (CA/ZnO) demonstrated faster and more efficient MB degradation, resulting in more than 30% of initial concentration. The results also revealed how the CA/ZnO combination effectively improves the membrane’s photocatalytic activity toward methylene blue (MB), showing that the degradation process of dye solutions to UV light is chemically and physically stable and cost-effective. This photocatalytic activity toward MB of the cellulose acetate membranes has the potential to make these membranes serious competitors for removing textile dye and other pollutants from aqueous solutions. Hence, polymer–ZnO composite membranes were considered a valuable and attractive topic in membrane technology.

Synthesis and Characterization of Blended Cellulose Acetate Membranes.

The casting and preparation of ultrafiltration ZnO modified cellulose acetate membrane (CA/ZnO) were investigated in this work. CA membranes were fabricated by phase inversion using dimethylformamide (DMF) as a solvent and ZnO as nanostructures materials. Ultrafiltration (UF) performance, mechanical stability, morphology, contact angle, and porosity were evaluated on both CA- and ZnO-modified CA samples. Scanning electron microscopy (SEM) was used to determine the morphology of the membranes, showing different pore sizes either on rough surfaces and cross-sections of the samples, an asymmetric structure and ultra-scale pores with an average pore radius 0.0261 to 0.045 µm. Contact angle measurements showed the highest hydrophobicity values for the samples with no ZnO addition, ranging between 48° and 82.7° on their airside. The permeability values decreased with the increasing CA concentration in the casting solution, as expected; however, ZnO-modified membranes produced lower flux than the pure CA ones. Nevertheless, ZnO modified CA membranes have higher surface pore size, pore density and porosity, and improved surface hydrophilicity compared with pure CA membranes. The results indicated that the incorporated nano-ZnO tends to limit the packing of the polymer chains onto the membrane structure while showing antifouling properties leading to better hydrophilicity and permeation with consistent UF applications.

Cellulose blends with polylactic acid or polyamide 6 from solution blending: Microstructure and polymer interactions

The use of cellulose in polymer blends is limited due to missing thermoplasticity and incompatibility with most synthetic polymers. In this work, a solvent-based rapid precipitation method was used to overcome these limitations. Blends of cellulose with polylactic acid or polyamide 6 were prepared using a previously presented ionic liquid-based solution-precipitation method. The structural properties of the blends and the specific intermolecular interactions were studied by FTIR, DSC, XRD and SEM. With polylactic acid, cellulose formed single-phase amorphous blends with intense intermolecular hydrogen bonding detected by FTIR. Less pronounced interactions were concluded for polyamide 6 and cellulose from FTIR, DSC and XRD, resulting in a two-phase morphological structure with continuous cellulose and dispersed polyamide 6 domains. Homogeneous blend formation between polylactic acid and cellulose could be promising for further material developments.

Effects of different hydrocolloids on the production of bacterial cellulose by Acetobacter xylinum using Hestrin–Schramm medium under anaerobic condition

In this study, the effect of hydrocolloids on the efficiency of bacterial cellulose (BC) biosynthesis by Acetobacter xylinum was investigated under anaerobic conditions using Hestrin–Schramm medium. With initial glucose concentration of 50 g/L, there was no BC formation while bacterial growth was still noticed through a decrease in pH, total acidity, and sugar content. However, the addition of xanthan gum (XG), blend of microcrystalline cellulose and carboxymethylcellulose (MCC), and konjac glucomannan (KJ) induced cellulose formation, leading to the presence of BC layers on the top of static fermentation medium. After 13 days of fermentation, HS medium supplemented with 0.2% KJ and 0.2% XG resulted in the highest BC production with dried BC content of 6.97 and 6.52 g/L, respectively. In addition, the thickness of the two samples XG and KJ was in the range of 2.54–3.54 mm, and MCC exhibited lowest effectiveness, regardless of its concentration.

Properties and applications of cellulose regenerated from cellulose/imidazolium-based ionic liquid/co-solvent solutions: A short review

AbstractAn improvement of ecological conscience currently has increased the consciousness of researchers in reducing the processing time and cost of solvent for the dissolution of cellulose. Latterly, ionic liquids have been employed to process cellulose as they are recyclable and nonvolatile. Besides that, biopolymers such as chitosan, chitin, starch, protein, and cellulose acetate can also be processed by using ionic liquids for diverse applications. In this short review, examples of imidazolium-based ionic liquids that are commonly used for the dissolution of cellulose are implied. Furthermore, examples of organic liquids that are utilized as co-solvents for ionic liquids were revealed. In addition, examples of imidazolium-based ionic liquid/co-solvent mixtures utilized in the dissolution of cellulose and other biopolymers are also demonstrated. The properties and applications of cellulose and its blends regenerated from different types of cellulose/imidazolium-based ionic liquid/co-solvent solutions are also shortly reviewed. The information acquired from this review gives a better understanding of the changes in the properties of regenerated cellulose and regenerated cellulose blends. In addition, this short review serves as a model basis for the creation of novel applications of regenerated cellulose and regenerated cellulose blends by utilizing imidazolium-based ionic liquid/co-solvent mixtures.

Biodegradable all-cellulose composite hydrogel as eco-friendly and efficient coating material for slow-release MAP fertilizer

In the attempt to develop a novel coated fertilizer with combined slow release and water retention properties, all-cellulose hydrogel formulation was applied as waterborne and swellable coating material of monoammonium phosphate fertilizer (MAP). The biodegradable formulation was prepared from sodium carboxymethyl cellulose/hydroxyethyl cellulose blend filled with 5% of spherical regenerated cellulose particles (CH@5RC). The coating process was performed in rotating pan and final coated products with two coating thicknesses and two crosslinking conditions were elaborated. A uniformly covered surface with increased crushing resistance up to 90.55 N and a positive impact on the soil water retention capacity were obtained after coating. Furthermore, the release experiment of phosphorus and nitrogen in water and soil media showed extended-release durations with maximal longevities of 12 h in water and 19–20 days in soil as compared to 1–2 h in water and 9–10 days in soil of uncoated MAP. The effect of the coating thickness and crosslinking condition on all investigated properties was taken into account. We assume in this work that cellulosic materials, being the main coating former of fertilizer, are capable to double the release time of MAP fertilizer with better preservation of the soil moisture.

New Insights on Solvent Implications in the Design of Materials Based on Cellulose Derivatives Using Experimental and Theoretical Approaches.

The current paper presents a strategic way to design and develop materials with properties adapted for various applications from biomedicine to environmental applications. In this context, blends of (hydroxypropyl)methyl cellulose (HPMC) and poly(vinylpyrrolidone) (PVP) were obtained to create new materials that can modulate the membrane properties in various fields. Thus, to explore the possibility of using the HPMC/PVP system in practical applications, the solubility parameters in various solvents were initially evaluated using experimental and theoretical approaches. In this frame, the study is aimed at presenting the background and steps of preliminary studies to validate the blends behavior for targeted application before being designed. Subsequently, the analysis of the behavior in aqueous dilute solution of HPMC/PVP blend offers information about the conformational modifications and interactions manifested in system depending on the structural characteristics of polymers (hydrophilicity, flexibility), polymer mixtures composition, and used solvent. Given this background, based on experimental and theoretical studies, knowledge of hydrodynamic parameters and analysis of the optimal compositions of polymer mixtures are essential for establishing the behavior of obtained materials and validation for most suitable applications. Additionally, to guarantee the quality and functionality of these composite materials in the targeted applications, e.g., biomedical or environmental, the choice of a suitable solvent played an important role.

Analysis of the Heterogeneities of First and Second Order of Cellulose Derivatives: A Complex Challenge

The complexity of the substituent distribution in polysaccharide derivatives is discussed and defined. The challenges regarding analytical characterization that results from various interrelated categories of distributions, including molecular weight, chemical composition, and microstructure, are outlined. Due to these convoluted levels of complexity, results should always be interpreted with carefulness. Various analytical approaches which have been applied to starch and cellulose derivatives are recapped, including enzymatic, mass spectrometric, and chromatographic methods. The relation of heterogeneities of first and second order among and along the polysaccharide chains is addressed. Finally, examples of own analytical work on cellulose ethers are presented, including the MS analysis of methyl cellulose (MC) blends and fractionation studies of fully esterified MC, especially its 4-methoxybenzoates by gradient HPLC on normal phase. Preparative fractionation according to the degree of substitution (DS) allows follow-up analysis in order to get more detailed information on the substituent distribution in such sub-fractions.