Please Help: Vector Logo Created in Illustrator is Pixelated Outside of Illustrator

I created a simple logo for my friend using the shape builder tool and plain text, and text typed on a path. I convertted everything to outlines. Then I exported my artwork as png files and when I opened them, they were pixelated. I have tried making sure the anti-aliasing box is checked, my artboards are set at 72dpi, I saved for web, exported for screens, nothing seems to be working. I have tried saving different file types and all are pixelated. Please help.