Reinforcement of Stereolithographic Resins for Rapid Prototyping with Cellulose Nanocrystals

We report on the mechanical properties of optically curable stereolithographic resins (SLRs) which were reinforced through the addition of small amounts of cellulose nanocrystals (CNCs). The resin/filler mixtures are readily accessible via simple mixing processes. A detailed rheological investigation of such mixtures and the successful processing of these materials on a commercial SLR machine show that at low filler concentrations (below 5%) the processability of the materials is barely impacted. The storage modulus, <i>E</i>′, increased steadily with increasing CNC content in the regimes below and above the glass transition. A remarkable modulus enhancement was observed in the rubbery regime, where <i>E</i>′ increased by 166, 233, and 587% for CNC/SLR nanocomposites with 0.5, 1.0, and 5.0% w/w CNC, respectively. The modulus increase was less pronounced in the glassy state, where <i>E</i>′ increased by 21, 32 and 57%, for the same compositions. The increase in tensile strength was of similar magnitude. In comparison to previously reported CNC and carbon-nanofiller based nanocomposites, the presently investigated nanocomposites display a comparably large increase of stiffness and strength, which appear to originate from the high level of dispersion and the intimate contact of the CNCs with the SLR matrix. Through the fabrication of 3-dimensional parts, it was shown that the CNC-filled resins can be processed with standard equipment in a stereolithographic process that is widely used for rapid prototyping and rapid manufacturing

Additional file 3: of Physical basis of the ‘magnification rule’ for standardized Immunohistochemical scoring of HER2 in breast and gastric cancer

Figure S3. Scatter-plot of HER2 DAB-precipitates width and color intensity. For scoring intensities 1+ and 2+ (grey), width and intensity show a linear correlation (r = 0.73, dashed lined). Scoring category 3+ shows saturated intensity (n = 1200 measurements in 40 cases per scoring category). (JPEG 585 kb

Additional file 1: of Physical basis of the ‘magnification rule’ for standardized Immunohistochemical scoring of HER2 in breast and gastric cancer

Figure S1. Example photomicrographs of HER2-IHC. Images depict scoring categories 1+, 2+ and 3+ at magnifications reflecting different microscope objectives (2.5× - 63×. Inserts: Magnified details, 4× additional magnification). Note that the linear DAB-precipitates in categories 1+ and 2+ are not perceivable at low power magnification (2.5×, 5×). (TIFF 47314 kb